feat: expand platform management, admin controls, and learning workflows

.gitignore

@@ -21,3 +21,6 @@
 .DS_Store
 .idea/
 .vscode/
+
+# Local PDF corpus for RAG generation
+data/local_pdfs/

README.md

@@ -106,6 +106,12 @@ OI_IMPORT_SCRIPT_PATH=/app/scripts/import_luogu_csp.py
 OI_IMPORT_CLEAR_ALL_PROBLEMS=true
 ```
 
+## 6.1 本地 PDF + RAG + LLM 扩充题库（CSP-J/S）
+
+`/imports` 页面支持切换到 `local_pdf_rag` 模式：从本地 PDF 抽取文本做 RAG，调用 LLM 生成 CSP-J/S 题目，并按现有题库相似度去重，跳过雷同题目，直到目标题量（如 5000）。
+
+默认目录：`/data/local_pdfs`（Compose 已挂载 `./data/local_pdfs:/data/local_pdfs`），建议先把 PDF 放到该目录。
+
 如果你还要使用旧的 PDF + LLM 导入流程，可手动运行 `scripts/import_winterant_oi.py`。
 
 ## 7. CSP-J 题目自动生成（RAG + 去重）

backend/include/csp/controllers/admin_controller.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <drogon/HttpController.h>
+
+#include <cstdint>
+
+namespace csp::controllers {
+
+class AdminController : public drogon::HttpController<AdminController> {
+ public:
+  METHOD_LIST_BEGIN
+  ADD_METHOD_TO(AdminController::listUsers, "/api/v1/admin/users", drogon::Get);
+  ADD_METHOD_TO(AdminController::updateUserRating,
+                "/api/v1/admin/users/{1}/rating",
+                drogon::Patch);
+  ADD_METHOD_TO(AdminController::listRedeemItems, "/api/v1/admin/redeem-items", drogon::Get);
+  ADD_METHOD_TO(AdminController::createRedeemItem, "/api/v1/admin/redeem-items", drogon::Post);
+  ADD_METHOD_TO(AdminController::updateRedeemItem,
+                "/api/v1/admin/redeem-items/{1}",
+                drogon::Patch);
+  ADD_METHOD_TO(AdminController::deleteRedeemItem,
+                "/api/v1/admin/redeem-items/{1}",
+                drogon::Delete);
+  ADD_METHOD_TO(AdminController::listRedeemRecords,
+                "/api/v1/admin/redeem-records",
+                drogon::Get);
+  METHOD_LIST_END
+
+  void listUsers(const drogon::HttpRequestPtr& req,
+                 std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void updateUserRating(const drogon::HttpRequestPtr& req,
+                        std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+                        int64_t user_id);
+
+  void listRedeemItems(const drogon::HttpRequestPtr& req,
+                       std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void createRedeemItem(const drogon::HttpRequestPtr& req,
+                        std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void updateRedeemItem(const drogon::HttpRequestPtr& req,
+                        std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+                        int64_t item_id);
+
+  void deleteRedeemItem(const drogon::HttpRequestPtr& req,
+                        std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+                        int64_t item_id);
+
+  void listRedeemRecords(const drogon::HttpRequestPtr& req,
+                         std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+};
+
+}  // namespace csp::controllers

backend/include/csp/controllers/meta_controller.h

@@ -8,12 +8,32 @@ class MetaController : public drogon::HttpController<MetaController> {
  public:
   METHOD_LIST_BEGIN
   ADD_METHOD_TO(MetaController::openapi, "/api/openapi.json", drogon::Get);
+  ADD_METHOD_TO(MetaController::backendLogs, "/api/v1/backend/logs", drogon::Get);
+  ADD_METHOD_TO(MetaController::kbRefreshStatus, "/api/v1/backend/kb/refresh", drogon::Get);
+  ADD_METHOD_TO(MetaController::triggerKbRefresh, "/api/v1/backend/kb/refresh", drogon::Post);
+  ADD_METHOD_TO(MetaController::triggerMissingSolutions, "/api/v1/backend/solutions/generate-missing",
+                drogon::Post);
   ADD_METHOD_TO(MetaController::mcp, "/api/v1/mcp", drogon::Post);
   METHOD_LIST_END
 
   void openapi(const drogon::HttpRequestPtr& req,
                std::function<void(const drogon::HttpResponsePtr&)>&& cb);
 
+  void backendLogs(const drogon::HttpRequestPtr& req,
+                   std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void kbRefreshStatus(
+      const drogon::HttpRequestPtr& req,
+      std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void triggerKbRefresh(
+      const drogon::HttpRequestPtr& req,
+      std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
+  void triggerMissingSolutions(
+      const drogon::HttpRequestPtr& req,
+      std::function<void(const drogon::HttpResponsePtr&)>&& cb);
+
   void mcp(const drogon::HttpRequestPtr& req,
            std::function<void(const drogon::HttpResponsePtr&)>&& cb);
 };

backend/include/csp/controllers/submission_controller.h

@@ -12,6 +12,7 @@ class SubmissionController : public drogon::HttpController<SubmissionController>
   ADD_METHOD_TO(SubmissionController::submitProblem, "/api/v1/problems/{1}/submit", drogon::Post);
   ADD_METHOD_TO(SubmissionController::listSubmissions, "/api/v1/submissions", drogon::Get);
   ADD_METHOD_TO(SubmissionController::getSubmission, "/api/v1/submissions/{1}", drogon::Get);
+  ADD_METHOD_TO(SubmissionController::analyzeSubmission, "/api/v1/submissions/{1}/analysis", drogon::Post);
   ADD_METHOD_TO(SubmissionController::runCpp, "/api/v1/run/cpp", drogon::Post);
   METHOD_LIST_END
 
@@ -26,6 +27,10 @@ class SubmissionController : public drogon::HttpController<SubmissionController>
                      std::function<void(const drogon::HttpResponsePtr&)>&& cb,
                      int64_t submission_id);
 
+  void analyzeSubmission(const drogon::HttpRequestPtr& req,
+                         std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+                         int64_t submission_id);
+
   void runCpp(const drogon::HttpRequestPtr& req,
               std::function<void(const drogon::HttpResponsePtr&)>&& cb);
 };

backend/include/csp/domain/entities.h

@@ -73,6 +73,7 @@ struct Submission {
   std::string code;
   SubmissionStatus status = SubmissionStatus::Pending;
   int32_t score = 0;
+  int32_t rating_delta = 0;
   int32_t time_ms = 0;
   int32_t memory_kb = 0;
   std::string compile_log;

backend/include/csp/services/auth_service.h

@@ -20,6 +20,7 @@ class AuthService {
   // Throws on error; for controller we will catch and convert to JSON.
   AuthResult Register(const std::string& username, const std::string& password);
   AuthResult Login(const std::string& username, const std::string& password);
+  void ResetPassword(const std::string& username, const std::string& new_password);
 
   std::optional<int> VerifyToken(const std::string& token);
 

backend/include/csp/services/import_runner.h

@@ -8,7 +8,11 @@
 namespace csp::services {
 
 struct ImportRunOptions {
+  std::string mode = "luogu";
   bool clear_all_problems = false;
+  std::string local_pdf_dir;
+  int target_total = 5000;
+  int workers = 3;
 };
 
 class ImportRunner {

backend/include/csp/services/kb_import_runner.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+#include <mutex>
+#include <optional>
+#include <string>
+
+namespace csp::services {
+
+class KbImportRunner {
+ public:
+  static KbImportRunner& Instance();
+
+  void Configure(std::string db_path);
+  bool TriggerAsync(const std::string& trigger);
+
+  bool IsRunning() const;
+  std::string LastCommand() const;
+  std::optional<int> LastExitCode() const;
+  int64_t LastStartedAt() const;
+  int64_t LastFinishedAt() const;
+  std::string LastTrigger() const;
+
+ private:
+  KbImportRunner() = default;
+
+  mutable std::mutex mu_;
+  std::string db_path_;
+  bool running_ = false;
+  std::string last_command_;
+  std::optional<int> last_exit_code_;
+  int64_t last_started_at_ = 0;
+  int64_t last_finished_at_ = 0;
+  std::string last_trigger_;
+};
+
+}  // namespace csp::services

backend/include/csp/services/problem_solution_runner.h

@@ -1,28 +1,59 @@
 #pragma once
 
+#include "csp/db/sqlite_db.h"
+
 #include <cstdint>
+#include <cstddef>
+#include <deque>
 #include <mutex>
 #include <optional>
-#include <set>
 #include <string>
+#include <unordered_map>
 
 namespace csp::services {
 
 class ProblemSolutionRunner {
  public:
+  struct TriggerMissingSummary {
+    int missing_total = 0;
+    int candidate_count = 0;
+    int queued_count = 0;
+  };
+
   static ProblemSolutionRunner& Instance();
 
   void Configure(std::string db_path);
 
   bool TriggerAsync(int64_t problem_id, int64_t job_id, int max_solutions);
+  TriggerMissingSummary TriggerMissingAsync(db::SqliteDb& db,
+                                            int64_t created_by,
+                                            int max_solutions,
+                                            int limit);
+  void AutoStartMissingIfEnabled(db::SqliteDb& db);
   bool IsRunning(int64_t problem_id) const;
+  size_t PendingCount() const;
 
  private:
+  struct Task {
+    int64_t problem_id = 0;
+    int64_t job_id = 0;
+    int max_solutions = 3;
+  };
+
   ProblemSolutionRunner() = default;
+  void StartWorkerIfNeededLocked();
+  void WorkerLoop();
+  void RecoverQueuedJobsLocked();
+  void StartAutoPumpIfNeeded(db::SqliteDb* db, int max_solutions, int limit, int interval_sec);
 
   std::string db_path_;
   mutable std::mutex mu_;
-  std::set<int64_t> running_problem_ids_;
+  std::deque<Task> queue_;
+  std::unordered_map<int64_t, size_t> pending_problem_counts_;
+  size_t pending_jobs_ = 0;
+  bool worker_running_ = false;
+  bool recovered_from_db_ = false;
+  bool auto_pump_started_ = false;
 };
 
 }  // namespace csp::services

backend/include/csp/services/problem_workspace_service.h

@@ -34,6 +34,7 @@ struct ProblemSolution {
 struct ProblemSolutionJob {
   int64_t id = 0;
   int64_t problem_id = 0;
+  std::string problem_title;
   std::string status;
   int progress = 0;
   std::string message;
@@ -60,7 +61,13 @@ class ProblemWorkspaceService {
 
   int64_t CreateSolutionJob(int64_t problem_id, int64_t created_by, int max_solutions);
   std::optional<ProblemSolutionJob> GetLatestSolutionJob(int64_t problem_id);
+  std::vector<ProblemSolutionJob> ListRecentSolutionJobs(int limit);
+  std::vector<ProblemSolutionJob> ListSolutionJobsByStatus(const std::string& status,
+                                                           int limit);
   std::vector<ProblemSolution> ListSolutions(int64_t problem_id);
+  int CountProblemsWithoutSolutions();
+  std::vector<int64_t> ListProblemIdsWithoutSolutions(int limit,
+                                                      bool exclude_queued_or_running_jobs);
 
  private:
   db::SqliteDb& db_;

backend/include/csp/services/redeem_service.h

@@ -0,0 +1,77 @@
+#pragma once
+
+#include "csp/db/sqlite_db.h"
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace csp::services {
+
+struct RedeemItem {
+  int64_t id = 0;
+  std::string name;
+  std::string description;
+  std::string unit_label;
+  int holiday_cost = 0;
+  int studyday_cost = 0;
+  bool is_active = true;
+  bool is_global = true;
+  int64_t created_by = 0;
+  int64_t created_at = 0;
+  int64_t updated_at = 0;
+};
+
+struct RedeemItemWrite {
+  std::string name;
+  std::string description;
+  std::string unit_label = "小时";
+  int holiday_cost = 5;
+  int studyday_cost = 25;
+  bool is_active = true;
+  bool is_global = true;
+};
+
+struct RedeemRecord {
+  int64_t id = 0;
+  int64_t user_id = 0;
+  int64_t item_id = 0;
+  std::string item_name;
+  int quantity = 1;
+  std::string day_type;
+  int unit_cost = 0;
+  int total_cost = 0;
+  std::string note;
+  int64_t created_at = 0;
+  std::string username;
+};
+
+struct RedeemRequest {
+  int64_t user_id = 0;
+  int64_t item_id = 0;
+  int quantity = 1;
+  std::string day_type = "studyday";
+  std::string note;
+};
+
+class RedeemService {
+ public:
+  explicit RedeemService(db::SqliteDb& db) : db_(db) {}
+
+  std::vector<RedeemItem> ListItems(bool include_inactive);
+  std::optional<RedeemItem> GetItemById(int64_t item_id);
+  RedeemItem CreateItem(int64_t admin_user_id, const RedeemItemWrite& input);
+  RedeemItem UpdateItem(int64_t item_id, const RedeemItemWrite& input);
+  void DeactivateItem(int64_t item_id);
+
+  std::vector<RedeemRecord> ListRecordsByUser(int64_t user_id, int limit);
+  std::vector<RedeemRecord> ListRecordsAll(std::optional<int64_t> user_id, int limit);
+
+  RedeemRecord Redeem(const RedeemRequest& request);
+
+ private:
+  db::SqliteDb& db_;
+};
+
+}  // namespace csp::services

backend/include/csp/services/solution_access_service.h

@@ -0,0 +1,44 @@
+#pragma once
+
+#include "csp/db/sqlite_db.h"
+
+#include <cstdint>
+#include <optional>
+#include <string>
+
+namespace csp::services {
+
+struct SolutionViewChargeResult {
+  bool granted = true;
+  bool charged = false;
+  bool daily_free = false;
+  int cost = 0;
+  int rating_before = 0;
+  int rating_after = 0;
+  int daily_used_count = 0;
+  int64_t viewed_at = 0;
+  std::string day_key;
+  std::string deny_reason;
+};
+
+struct SolutionViewStats {
+  bool has_viewed = false;
+  int total_views = 0;
+  int total_cost = 0;
+  std::optional<int64_t> last_viewed_at;
+};
+
+class SolutionAccessService {
+ public:
+  explicit SolutionAccessService(db::SqliteDb& db) : db_(db) {}
+
+  // Daily policy: first answer view is free, then each full view costs 2 rating.
+  SolutionViewChargeResult ConsumeSolutionView(int64_t user_id, int64_t problem_id);
+
+  SolutionViewStats QueryUserProblemViewStats(int64_t user_id, int64_t problem_id);
+
+ private:
+  db::SqliteDb& db_;
+};
+
+}  // namespace csp::services

backend/include/csp/services/submission_feedback_service.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "csp/db/sqlite_db.h"
+#include "csp/domain/entities.h"
+
+#include <cstdint>
+#include <optional>
+#include <string>
+
+namespace csp::services {
+
+struct SubmissionFeedback {
+  int64_t submission_id = 0;
+  std::string feedback_md;
+  std::string links_json;
+  std::string model_name;
+  std::string status;
+  int64_t created_at = 0;
+  int64_t updated_at = 0;
+};
+
+class SubmissionFeedbackService {
+ public:
+  explicit SubmissionFeedbackService(db::SqliteDb& db) : db_(db) {}
+
+  std::optional<SubmissionFeedback> GetBySubmissionId(int64_t submission_id);
+
+  SubmissionFeedback GenerateAndSave(const domain::Submission& submission,
+                                     const domain::Problem& problem,
+                                     bool force_refresh);
+
+ private:
+  db::SqliteDb& db_;
+};
+
+}  // namespace csp::services

backend/include/csp/services/user_service.h

@@ -9,12 +9,19 @@
 
 namespace csp::services {
 
+struct UserListResult {
+  std::vector<domain::GlobalLeaderboardEntry> items;
+  int total_count = 0;
+};
+
 class UserService {
  public:
   explicit UserService(db::SqliteDb& db) : db_(db) {}
 
   std::optional<domain::User> GetById(int64_t id);
   std::vector<domain::GlobalLeaderboardEntry> GlobalLeaderboard(int limit = 100);
+  UserListResult ListUsers(int page, int page_size);
+  void SetRating(int64_t user_id, int rating);
 
  private:
   db::SqliteDb& db_;

backend/src/controllers/admin_controller.cc

@@ -0,0 +1,320 @@
+#include "csp/controllers/admin_controller.h"
+
+#include "csp/app_state.h"
+#include "csp/services/redeem_service.h"
+#include "csp/services/user_service.h"
+#include "http_auth.h"
+
+#include <algorithm>
+#include <cctype>
+#include <exception>
+#include <optional>
+#include <stdexcept>
+#include <string>
+
+namespace csp::controllers {
+
+namespace {
+
+drogon::HttpResponsePtr JsonError(drogon::HttpStatusCode code,
+                                  const std::string& msg) {
+  Json::Value j;
+  j["ok"] = false;
+  j["error"] = msg;
+  auto resp = drogon::HttpResponse::newHttpJsonResponse(j);
+  resp->setStatusCode(code);
+  return resp;
+}
+
+drogon::HttpResponsePtr JsonOk(const Json::Value& data) {
+  Json::Value j;
+  j["ok"] = true;
+  j["data"] = data;
+  auto resp = drogon::HttpResponse::newHttpJsonResponse(j);
+  resp->setStatusCode(drogon::k200OK);
+  return resp;
+}
+
+int ParseClampedInt(const std::string& s,
+                    int default_value,
+                    int min_value,
+                    int max_value) {
+  if (s.empty()) return default_value;
+  const int v = std::stoi(s);
+  return std::max(min_value, std::min(max_value, v));
+}
+
+bool ParseBoolLike(const std::string& raw, bool default_value) {
+  if (raw.empty()) return default_value;
+  std::string v = raw;
+  std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
+    return static_cast<char>(std::tolower(c));
+  });
+  if (v == "1" || v == "true" || v == "yes" || v == "on") return true;
+  if (v == "0" || v == "false" || v == "no" || v == "off") return false;
+  return default_value;
+}
+
+std::optional<int64_t> ParseOptionalInt64(const std::string& raw) {
+  if (raw.empty()) return std::nullopt;
+  return std::stoll(raw);
+}
+
+services::RedeemItemWrite ParseRedeemItemWrite(const Json::Value& json) {
+  services::RedeemItemWrite write;
+  write.name = json.get("name", "").asString();
+  write.description = json.get("description", "").asString();
+  write.unit_label = json.get("unit_label", "小时").asString();
+  write.holiday_cost = json.get("holiday_cost", 5).asInt();
+  write.studyday_cost = json.get("studyday_cost", 25).asInt();
+  write.is_active = json.get("is_active", true).asBool();
+  write.is_global = json.get("is_global", true).asBool();
+  return write;
+}
+
+Json::Value ToJson(const services::RedeemItem& item) {
+  Json::Value j;
+  j["id"] = Json::Int64(item.id);
+  j["name"] = item.name;
+  j["description"] = item.description;
+  j["unit_label"] = item.unit_label;
+  j["holiday_cost"] = item.holiday_cost;
+  j["studyday_cost"] = item.studyday_cost;
+  j["is_active"] = item.is_active;
+  j["is_global"] = item.is_global;
+  j["created_by"] = Json::Int64(item.created_by);
+  j["created_at"] = Json::Int64(item.created_at);
+  j["updated_at"] = Json::Int64(item.updated_at);
+  return j;
+}
+
+std::optional<int64_t> RequireAdminUserId(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>& cb) {
+  std::string auth_error;
+  const auto user_id = GetAuthedUserId(req, auth_error);
+  if (!user_id.has_value()) {
+    cb(JsonError(drogon::k401Unauthorized, auth_error));
+    return std::nullopt;
+  }
+
+  services::UserService users(csp::AppState::Instance().db());
+  const auto user = users.GetById(*user_id);
+  if (!user.has_value() || user->username != "admin") {
+    cb(JsonError(drogon::k403Forbidden, "admin only"));
+    return std::nullopt;
+  }
+  return user_id;
+}
+
+}  // namespace
+
+void AdminController::listUsers(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
+    const int page = ParseClampedInt(req->getParameter("page"), 1, 1, 100000);
+    const int page_size =
+        ParseClampedInt(req->getParameter("page_size"), 50, 1, 200);
+
+    services::UserService users(csp::AppState::Instance().db());
+    const auto result = users.ListUsers(page, page_size);
+
+    Json::Value arr(Json::arrayValue);
+    for (const auto& item : result.items) {
+      Json::Value one;
+      one["id"] = Json::Int64(item.user_id);
+      one["username"] = item.username;
+      one["rating"] = item.rating;
+      one["created_at"] = Json::Int64(item.created_at);
+      arr.append(one);
+    }
+
+    Json::Value payload;
+    payload["items"] = arr;
+    payload["total_count"] = result.total_count;
+    payload["page"] = page;
+    payload["page_size"] = page_size;
+    cb(JsonOk(payload));
+  } catch (const std::invalid_argument&) {
+    cb(JsonError(drogon::k400BadRequest, "invalid query parameter"));
+  } catch (const std::out_of_range&) {
+    cb(JsonError(drogon::k400BadRequest, "query parameter out of range"));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::updateUserRating(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+    int64_t user_id) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
+    const auto json = req->getJsonObject();
+    if (!json) {
+      cb(JsonError(drogon::k400BadRequest, "body must be json"));
+      return;
+    }
+
+    if (!(*json).isMember("rating")) {
+      cb(JsonError(drogon::k400BadRequest, "rating is required"));
+      return;
+    }
+    const int rating = (*json)["rating"].asInt();
+    if (rating < 0) {
+      cb(JsonError(drogon::k400BadRequest, "rating must be >= 0"));
+      return;
+    }
+
+    services::UserService users(csp::AppState::Instance().db());
+    users.SetRating(user_id, rating);
+
+    const auto updated = users.GetById(user_id);
+    if (!updated.has_value()) {
+      cb(JsonError(drogon::k404NotFound, "user not found"));
+      return;
+    }
+
+    Json::Value payload;
+    payload["id"] = Json::Int64(updated->id);
+    payload["username"] = updated->username;
+    payload["rating"] = updated->rating;
+    payload["updated"] = true;
+    cb(JsonOk(payload));
+  } catch (const std::invalid_argument&) {
+    cb(JsonError(drogon::k400BadRequest, "invalid rating"));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::listRedeemItems(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
+    const bool include_inactive =
+        ParseBoolLike(req->getParameter("include_inactive"), true);
+    services::RedeemService redeem(csp::AppState::Instance().db());
+    const auto items = redeem.ListItems(include_inactive);
+
+    Json::Value arr(Json::arrayValue);
+    for (const auto& item : items) arr.append(ToJson(item));
+    cb(JsonOk(arr));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::createRedeemItem(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    const auto admin_user_id = RequireAdminUserId(req, cb);
+    if (!admin_user_id.has_value()) return;
+
+    const auto json = req->getJsonObject();
+    if (!json) {
+      cb(JsonError(drogon::k400BadRequest, "body must be json"));
+      return;
+    }
+
+    const auto input = ParseRedeemItemWrite(*json);
+    services::RedeemService redeem(csp::AppState::Instance().db());
+    const auto item = redeem.CreateItem(*admin_user_id, input);
+    cb(JsonOk(ToJson(item)));
+  } catch (const std::runtime_error& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::updateRedeemItem(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+    int64_t item_id) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
+    const auto json = req->getJsonObject();
+    if (!json) {
+      cb(JsonError(drogon::k400BadRequest, "body must be json"));
+      return;
+    }
+
+    const auto input = ParseRedeemItemWrite(*json);
+    services::RedeemService redeem(csp::AppState::Instance().db());
+    const auto item = redeem.UpdateItem(item_id, input);
+    cb(JsonOk(ToJson(item)));
+  } catch (const std::runtime_error& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::deleteRedeemItem(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+    int64_t item_id) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+    services::RedeemService redeem(csp::AppState::Instance().db());
+    redeem.DeactivateItem(item_id);
+
+    Json::Value payload;
+    payload["id"] = Json::Int64(item_id);
+    payload["deleted"] = true;
+    cb(JsonOk(payload));
+  } catch (const std::runtime_error& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void AdminController::listRedeemRecords(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
+  try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
+    const auto user_id = ParseOptionalInt64(req->getParameter("user_id"));
+    const int limit = ParseClampedInt(req->getParameter("limit"), 200, 1, 500);
+
+    services::RedeemService redeem(csp::AppState::Instance().db());
+    const auto rows = redeem.ListRecordsAll(user_id, limit);
+
+    Json::Value arr(Json::arrayValue);
+    for (const auto& row : rows) {
+      Json::Value j;
+      j["id"] = Json::Int64(row.id);
+      j["user_id"] = Json::Int64(row.user_id);
+      j["username"] = row.username;
+      j["item_id"] = Json::Int64(row.item_id);
+      j["item_name"] = row.item_name;
+      j["quantity"] = row.quantity;
+      j["day_type"] = row.day_type;
+      j["unit_cost"] = row.unit_cost;
+      j["total_cost"] = row.total_cost;
+      j["note"] = row.note;
+      j["created_at"] = Json::Int64(row.created_at);
+      arr.append(j);
+    }
+    cb(JsonOk(arr));
+  } catch (const std::invalid_argument&) {
+    cb(JsonError(drogon::k400BadRequest, "invalid query parameter"));
+  } catch (const std::out_of_range&) {
+    cb(JsonError(drogon::k400BadRequest, "query parameter out of range"));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+}  // namespace csp::controllers

backend/src/controllers/import_controller.cc

@@ -3,9 +3,12 @@
 #include "csp/app_state.h"
 #include "csp/services/import_runner.h"
 #include "csp/services/import_service.h"
+#include "csp/services/user_service.h"
+#include "http_auth.h"
 
 #include <algorithm>
 #include <exception>
+#include <optional>
 #include <string>
 
 namespace csp::controllers {
@@ -40,6 +43,25 @@ int ParsePositiveInt(const std::string& s,
   return std::max(min_value, std::min(max_value, v));
 }
 
+std::optional<int64_t> RequireAdminUserId(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>& cb) {
+  std::string auth_error;
+  const auto user_id = GetAuthedUserId(req, auth_error);
+  if (!user_id.has_value()) {
+    cb(JsonError(drogon::k401Unauthorized, auth_error));
+    return std::nullopt;
+  }
+
+  services::UserService users(csp::AppState::Instance().db());
+  const auto user = users.GetById(*user_id);
+  if (!user.has_value() || user->username != "admin") {
+    cb(JsonError(drogon::k403Forbidden, "admin only"));
+    return std::nullopt;
+  }
+  return user_id;
+}
+
 Json::Value ToJson(const services::ImportJob& job) {
   Json::Value j;
   j["id"] = Json::Int64(job.id);
@@ -94,9 +116,11 @@ Json::Value ToJson(const services::ImportJobItem& item) {
 }  // namespace
 
 void ImportController::latestJob(
-    const drogon::HttpRequestPtr& /*req*/,
+    const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     services::ImportService svc(csp::AppState::Instance().db());
     Json::Value payload;
     const auto job = svc.GetLatestJob();
@@ -113,10 +137,12 @@ void ImportController::latestJob(
 }
 
 void ImportController::jobById(
-    const drogon::HttpRequestPtr& /*req*/,
+    const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb,
     int64_t job_id) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     services::ImportService svc(csp::AppState::Instance().db());
     const auto job = svc.GetById(job_id);
     if (!job.has_value()) {
@@ -136,6 +162,8 @@ void ImportController::jobItems(
     std::function<void(const drogon::HttpResponsePtr&)>&& cb,
     int64_t job_id) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     services::ImportJobItemQuery query;
     query.status = req->getParameter("status");
     query.page = ParsePositiveInt(req->getParameter("page"), 1, 1, 100000);
@@ -164,12 +192,26 @@ void ImportController::runJob(
     const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     services::ImportRunOptions opts;
     const auto json = req->getJsonObject();
     if (json) {
+      if ((*json).isMember("mode")) {
+        opts.mode = (*json)["mode"].asString();
+      }
       opts.clear_all_problems =
           (*json).isMember("clear_all_problems") &&
           (*json)["clear_all_problems"].asBool();
+      if ((*json).isMember("local_pdf_dir")) {
+        opts.local_pdf_dir = (*json)["local_pdf_dir"].asString();
+      }
+      if ((*json).isMember("target_total")) {
+        opts.target_total = std::max(1, std::min(50000, (*json)["target_total"].asInt()));
+      }
+      if ((*json).isMember("workers")) {
+        opts.workers = std::max(1, std::min(16, (*json)["workers"].asInt()));
+      }
     }
     const bool started =
         services::ImportRunner::Instance().TriggerAsync("manual", opts);
@@ -181,6 +223,7 @@ void ImportController::runJob(
     Json::Value payload;
     payload["started"] = true;
     payload["running"] = true;
+    payload["mode"] = opts.mode;
     cb(JsonOk(payload));
   } catch (const std::exception& e) {
     cb(JsonError(drogon::k500InternalServerError, e.what()));

backend/src/controllers/meta_controller.cc

@@ -9,10 +9,12 @@
 #include "csp/services/problem_solution_runner.h"
 #include "csp/services/problem_workspace_service.h"
 #include "csp/services/submission_service.h"
+#include "csp/services/user_service.h"
 #include "http_auth.h"
 
 #include <algorithm>
 #include <exception>
+#include <optional>
 #include <string>
 
 namespace csp::controllers {
@@ -47,6 +49,25 @@ int ParsePositiveInt(const std::string& s,
   return std::max(min_value, std::min(max_value, v));
 }
 
+std::optional<int64_t> RequireAdminUserId(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>& cb) {
+  std::string auth_error;
+  const auto user_id = GetAuthedUserId(req, auth_error);
+  if (!user_id.has_value()) {
+    cb(JsonError(drogon::k401Unauthorized, auth_error));
+    return std::nullopt;
+  }
+
+  services::UserService users(csp::AppState::Instance().db());
+  const auto user = users.GetById(*user_id);
+  if (!user.has_value() || user->username != "admin") {
+    cb(JsonError(drogon::k403Forbidden, "admin only"));
+    return std::nullopt;
+  }
+  return user_id;
+}
+
 Json::Value BuildOpenApiSpec() {
   Json::Value root;
   root["openapi"] = "3.1.0";
@@ -173,6 +194,8 @@ void MetaController::backendLogs(
     const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     const int limit =
         ParsePositiveInt(req->getParameter("limit"), 100, 1, 500);
     const int running_limit =
@@ -274,9 +297,11 @@ void MetaController::backendLogs(
 }
 
 void MetaController::kbRefreshStatus(
-    const drogon::HttpRequestPtr& /*req*/,
+    const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
+    if (!RequireAdminUserId(req, cb).has_value()) return;
+
     const auto& runner = services::KbImportRunner::Instance();
     Json::Value payload;
     payload["running"] = runner.IsRunning();
@@ -299,12 +324,7 @@ void MetaController::triggerKbRefresh(
     const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
-    std::string auth_error;
-    const auto user_id = GetAuthedUserId(req, auth_error);
-    if (!user_id.has_value()) {
-      cb(JsonError(drogon::k401Unauthorized, auth_error));
-      return;
-    }
+    if (!RequireAdminUserId(req, cb).has_value()) return;
 
     auto& runner = services::KbImportRunner::Instance();
     const bool started = runner.TriggerAsync("manual");
@@ -332,12 +352,8 @@ void MetaController::triggerMissingSolutions(
     const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb) {
   try {
-    std::string auth_error;
-    const auto user_id = GetAuthedUserId(req, auth_error);
-    if (!user_id.has_value()) {
-      cb(JsonError(drogon::k401Unauthorized, auth_error));
-      return;
-    }
+    const auto user_id = RequireAdminUserId(req, cb);
+    if (!user_id.has_value()) return;
 
     int limit = 50000;
     int max_solutions = 3;

backend/src/controllers/problem_controller.cc

@@ -5,6 +5,7 @@
 #include "csp/services/problem_service.h"
 #include "csp/services/problem_solution_runner.h"
 #include "csp/services/problem_workspace_service.h"
+#include "csp/services/solution_access_service.h"
 #include "http_auth.h"
 
 #include <algorithm>
@@ -192,7 +193,7 @@ void ProblemController::saveDraft(
 }
 
 void ProblemController::listSolutions(
-    const drogon::HttpRequestPtr& /*req*/,
+    const drogon::HttpRequestPtr& req,
     std::function<void(const drogon::HttpResponsePtr&)>&& cb,
     int64_t problem_id) {
   try {
@@ -203,28 +204,72 @@ void ProblemController::listSolutions(
     }
 
     const auto rows = svc.ListSolutions(problem_id);
+    const bool has_solutions = !rows.empty();
     const auto latest_job = svc.GetLatestSolutionJob(problem_id);
+    const std::string mode = req->getParameter("mode");
+    const bool need_full = mode == "full";
 
     Json::Value arr(Json::arrayValue);
-    for (const auto& item : rows) {
-      Json::Value j;
-      j["id"] = Json::Int64(item.id);
-      j["problem_id"] = Json::Int64(item.problem_id);
-      j["variant"] = item.variant;
-      j["title"] = item.title;
-      j["idea_md"] = item.idea_md;
-      j["explanation_md"] = item.explanation_md;
-      j["code_cpp"] = item.code_cpp;
-      j["complexity"] = item.complexity;
-      j["tags_json"] = item.tags_json;
-      j["source"] = item.source;
-      j["created_at"] = Json::Int64(item.created_at);
-      j["updated_at"] = Json::Int64(item.updated_at);
-      arr.append(j);
+    Json::Value access(Json::objectValue);
+    access["required"] = true;
+    access["daily_free_quota"] = 1;
+    access["cost_after_free"] = 2;
+
+    if (need_full && has_solutions) {
+      std::string auth_error;
+      const auto user_id = GetAuthedUserId(req, auth_error);
+      if (!user_id.has_value()) {
+        cb(JsonError(drogon::k401Unauthorized, auth_error));
+        return;
+      }
+
+      services::SolutionAccessService access_svc(csp::AppState::Instance().db());
+      const auto charge = access_svc.ConsumeSolutionView(*user_id, problem_id);
+      if (!charge.granted) {
+        cb(JsonError(drogon::k402PaymentRequired,
+                     "rating 不足：首次免费后每次查看答案需 2 分"));
+        return;
+      }
+
+      access["mode"] = "full";
+      access["charged"] = charge.charged;
+      access["daily_free"] = charge.daily_free;
+      access["cost"] = charge.cost;
+      access["day_key"] = charge.day_key;
+      access["daily_used_count"] = charge.daily_used_count;
+      access["rating_before"] = charge.rating_before;
+      access["rating_after"] = charge.rating_after;
+      access["viewed_at"] = Json::Int64(charge.viewed_at);
+
+      for (const auto& item : rows) {
+        Json::Value j;
+        j["id"] = Json::Int64(item.id);
+        j["problem_id"] = Json::Int64(item.problem_id);
+        j["variant"] = item.variant;
+        j["title"] = item.title;
+        j["idea_md"] = item.idea_md;
+        j["explanation_md"] = item.explanation_md;
+        j["code_cpp"] = item.code_cpp;
+        j["complexity"] = item.complexity;
+        j["tags_json"] = item.tags_json;
+        j["source"] = item.source;
+        j["created_at"] = Json::Int64(item.created_at);
+        j["updated_at"] = Json::Int64(item.updated_at);
+        arr.append(j);
+      }
+    } else {
+      access["mode"] = "preview";
+      access["charged"] = false;
+      access["daily_free"] = false;
+      access["cost"] = 0;
+      access["daily_used_count"] = 0;
     }
 
     Json::Value payload;
     payload["items"] = arr;
+    payload["has_solutions"] = has_solutions;
+    payload["answer_status"] = has_solutions ? "已有" : "待生成";
+    payload["access"] = access;
     payload["runner_running"] =
         services::ProblemSolutionRunner::Instance().IsRunning(problem_id);
     if (latest_job.has_value()) {
@@ -280,16 +325,20 @@ void ProblemController::generateSolutions(
     }
 
     const int64_t job_id = svc.CreateSolutionJob(problem_id, *user_id, max_solutions);
-    const bool started = services::ProblemSolutionRunner::Instance().TriggerAsync(
+    auto& runner = services::ProblemSolutionRunner::Instance();
+    const bool queued = runner.TriggerAsync(
         problem_id, job_id, max_solutions);
-    if (!started) {
-      cb(JsonError(drogon::k409Conflict, "solution generation is already running"));
+    if (!queued) {
+      cb(JsonError(drogon::k500InternalServerError,
+                   "solution generation queue is unavailable"));
       return;
     }
 
     Json::Value payload;
+    payload["queued"] = true;
     payload["started"] = true;
     payload["job_id"] = Json::Int64(job_id);
+    payload["pending_jobs"] = Json::UInt64(runner.PendingCount());
     cb(JsonOk(payload));
   } catch (const std::exception& e) {
     cb(JsonError(drogon::k500InternalServerError, e.what()));

backend/src/controllers/submission_controller.cc

@@ -4,11 +4,16 @@
 #include "csp/domain/enum_strings.h"
 #include "csp/domain/json.h"
 #include "csp/services/contest_service.h"
+#include "csp/services/problem_service.h"
+#include "csp/services/solution_access_service.h"
+#include "csp/services/submission_feedback_service.h"
 #include "csp/services/submission_service.h"
 #include "http_auth.h"
 
 #include <algorithm>
+#include <cctype>
 #include <exception>
+#include <memory>
 #include <optional>
 #include <string>
 
@@ -49,6 +54,32 @@ std::optional<int64_t> ParseOptionalInt64(const std::string& s) {
   return std::stoll(s);
 }
 
+bool ParseBoolLike(const std::string& s, bool default_value) {
+  if (s.empty()) return default_value;
+  std::string v = s;
+  std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
+    return static_cast<char>(std::tolower(c));
+  });
+  if (v == "1" || v == "true" || v == "yes" || v == "on") return true;
+  if (v == "0" || v == "false" || v == "no" || v == "off") return false;
+  return default_value;
+}
+
+Json::Value ParseLinksArray(const std::string& links_json) {
+  Json::CharReaderBuilder builder;
+  Json::Value parsed;
+  std::string errs;
+  std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  if (!reader->parse(links_json.data(),
+                     links_json.data() + links_json.size(),
+                     &parsed,
+                     &errs) ||
+      !parsed.isArray()) {
+    return Json::Value(Json::arrayValue);
+  }
+  return parsed;
+}
+
 }  // namespace
 
 void SubmissionController::submitProblem(
@@ -153,7 +184,91 @@ void SubmissionController::getSubmission(
       cb(JsonError(drogon::k404NotFound, "submission not found"));
       return;
     }
-    cb(JsonOk(domain::ToJson(*s)));
+    Json::Value payload = domain::ToJson(*s);
+    payload["code"] = s->code;
+
+    services::SolutionAccessService access_svc(csp::AppState::Instance().db());
+    const auto stats =
+        access_svc.QueryUserProblemViewStats(s->user_id, s->problem_id);
+    payload["has_viewed_answer"] = stats.has_viewed;
+    payload["answer_view_count"] = stats.total_views;
+    payload["answer_view_total_cost"] = stats.total_cost;
+    if (stats.last_viewed_at.has_value()) {
+      payload["last_answer_view_at"] = Json::Int64(*stats.last_viewed_at);
+    } else {
+      payload["last_answer_view_at"] = Json::nullValue;
+    }
+
+    services::SubmissionFeedbackService feedback_svc(csp::AppState::Instance().db());
+    if (const auto feedback = feedback_svc.GetBySubmissionId(s->id);
+        feedback.has_value()) {
+      Json::Value analysis;
+      analysis["feedback_md"] = feedback->feedback_md;
+      analysis["links"] = ParseLinksArray(feedback->links_json);
+      analysis["model_name"] = feedback->model_name;
+      analysis["status"] = feedback->status;
+      analysis["created_at"] = Json::Int64(feedback->created_at);
+      analysis["updated_at"] = Json::Int64(feedback->updated_at);
+      payload["analysis"] = analysis;
+    } else {
+      payload["analysis"] = Json::nullValue;
+    }
+
+    cb(JsonOk(payload));
+  } catch (const std::exception& e) {
+    cb(JsonError(drogon::k500InternalServerError, e.what()));
+  }
+}
+
+void SubmissionController::analyzeSubmission(
+    const drogon::HttpRequestPtr& req,
+    std::function<void(const drogon::HttpResponsePtr&)>&& cb,
+    int64_t submission_id) {
+  try {
+    std::string auth_error;
+    if (!GetAuthedUserId(req, auth_error).has_value()) {
+      cb(JsonError(drogon::k401Unauthorized, auth_error));
+      return;
+    }
+
+    bool force_refresh = ParseBoolLike(req->getParameter("refresh"), false);
+    if (const auto json = req->getJsonObject();
+        json && (*json).isMember("refresh")) {
+      force_refresh = (*json)["refresh"].asBool();
+    }
+
+    services::SubmissionService submission_svc(csp::AppState::Instance().db());
+    const auto submission = submission_svc.GetById(submission_id);
+    if (!submission.has_value()) {
+      cb(JsonError(drogon::k404NotFound, "submission not found"));
+      return;
+    }
+
+    services::ProblemService problem_svc(csp::AppState::Instance().db());
+    const auto problem = problem_svc.GetById(submission->problem_id);
+    if (!problem.has_value()) {
+      cb(JsonError(drogon::k404NotFound, "problem not found"));
+      return;
+    }
+
+    services::SubmissionFeedbackService feedback_svc(csp::AppState::Instance().db());
+    const auto feedback =
+        feedback_svc.GenerateAndSave(*submission, *problem, force_refresh);
+
+    Json::Value payload;
+    payload["submission_id"] = Json::Int64(feedback.submission_id);
+    payload["feedback_md"] = feedback.feedback_md;
+    payload["links"] = ParseLinksArray(feedback.links_json);
+    payload["model_name"] = feedback.model_name;
+    payload["status"] = feedback.status;
+    payload["created_at"] = Json::Int64(feedback.created_at);
+    payload["updated_at"] = Json::Int64(feedback.updated_at);
+    payload["refresh"] = force_refresh;
+    cb(JsonOk(payload));
+  } catch (const std::invalid_argument&) {
+    cb(JsonError(drogon::k400BadRequest, "invalid request field"));
+  } catch (const std::runtime_error& e) {
+    cb(JsonError(drogon::k400BadRequest, e.what()));
   } catch (const std::exception& e) {
     cb(JsonError(drogon::k500InternalServerError, e.what()));
   }

backend/src/domain/json.cc

@@ -40,6 +40,7 @@ Json::Value ToJson(const Submission& s) {
   j["language"] = ToString(s.language);
   j["status"] = ToString(s.status);
   j["score"] = s.score;
+  j["rating_delta"] = s.rating_delta;
   j["time_ms"] = s.time_ms;
   j["memory_kb"] = s.memory_kb;
   j["compile_log"] = s.compile_log;

backend/src/main.cc

@@ -3,6 +3,7 @@
 #include "csp/app_state.h"
 #include "csp/services/auth_service.h"
 #include "csp/services/import_runner.h"
+#include "csp/services/kb_import_runner.h"
 #include "csp/services/problem_gen_runner.h"
 #include "csp/services/problem_solution_runner.h"
 
@@ -16,6 +17,7 @@ int main(int argc, char** argv) {
 
   csp::AppState::Instance().Init(db_path);
   csp::services::ImportRunner::Instance().Configure(db_path);
+  csp::services::KbImportRunner::Instance().Configure(db_path);
   csp::services::ProblemSolutionRunner::Instance().Configure(db_path);
   csp::services::ProblemGenRunner::Instance().Configure(db_path);
 
@@ -26,10 +28,14 @@ int main(int argc, char** argv) {
     if (u && p && std::string(u).size() > 0 && std::string(p).size() > 0) {
       try {
         csp::services::AuthService auth(csp::AppState::Instance().db());
-        auth.Register(u, p);
-        LOG_INFO << "seed admin user created: " << u;
+        try {
+          auth.Register(u, p);
+          LOG_INFO << "seed admin user created: " << u;
+        } catch (const std::exception&) {
+          auth.ResetPassword(u, p);
+          LOG_INFO << "seed admin password reset: " << u;
+        }
       } catch (const std::exception& e) {
-        // Most likely UNIQUE constraint (already exists)
         LOG_INFO << "seed admin user skipped: " << e.what();
       }
     }
@@ -37,6 +43,9 @@ int main(int argc, char** argv) {
 
   // Auto-run PDF -> LLM import workflow on startup unless explicitly disabled.
   csp::services::ImportRunner::Instance().AutoStartIfEnabled();
+  // Auto-queue missing problem solutions on startup (C++14 async generation).
+  csp::services::ProblemSolutionRunner::Instance().AutoStartMissingIfEnabled(
+      csp::AppState::Instance().db());
   // Auto-generate one CSP-J new problem (RAG + dedupe) on startup by default.
   csp::services::ProblemGenRunner::Instance().AutoStartIfEnabled();
 

backend/src/services/import_runner.cc

@@ -1,11 +1,16 @@
 #include "csp/services/import_runner.h"
 
 #include <drogon/drogon.h>
+#include <json/json.h>
+#include <sqlite3.h>
 
+#include <algorithm>
 #include <chrono>
 #include <cctype>
 #include <cstdlib>
 #include <filesystem>
+#include <memory>
+#include <string>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -39,6 +44,13 @@ int EnvInt(const char* key, int default_value) {
   }
 }
 
+std::string EnvString(const char* key, const std::string& default_value) {
+  const char* raw = std::getenv(key);
+  if (!raw) return default_value;
+  const std::string value(raw);
+  return value.empty() ? default_value : value;
+}
+
 std::string ShellQuote(const std::string& text) {
   std::string out = "'";
   for (char c : text) {
@@ -52,7 +64,16 @@ std::string ShellQuote(const std::string& text) {
   return out;
 }
 
-std::string ResolveScriptPath() {
+std::string NormalizeMode(std::string mode) {
+  for (auto& c : mode) c = static_cast<char>(::tolower(static_cast<unsigned char>(c)));
+  if (mode == "local_pdf_rag" || mode == "local-pdf-rag" || mode == "local_rag" ||
+      mode == "rag") {
+    return "local_pdf_rag";
+  }
+  return "luogu";
+}
+
+std::string ResolveLuoguScriptPath() {
   const char* env_path = std::getenv("OI_IMPORT_SCRIPT_PATH");
   if (env_path && std::filesystem::exists(env_path)) return env_path;
 
@@ -72,11 +93,28 @@ std::string ResolveScriptPath() {
   return "/app/scripts/import_luogu_csp.py";
 }
 
-std::string BuildCommand(const std::string& db_path,
-                         const std::string& trigger,
-                         const ImportRunOptions& options) {
-  const std::string script_path = ResolveScriptPath();
-  const int workers = std::max(1, EnvInt("OI_IMPORT_WORKERS", 3));
+std::string ResolveLocalRagScriptPath() {
+  const char* env_path = std::getenv("OI_IMPORT_LOCAL_RAG_SCRIPT_PATH");
+  if (env_path && std::filesystem::exists(env_path)) return env_path;
+
+  const std::vector<std::string> candidates = {
+      "/app/scripts/import_local_pdf_rag.py",
+      "scripts/import_local_pdf_rag.py",
+      "../scripts/import_local_pdf_rag.py",
+      "../../scripts/import_local_pdf_rag.py",
+  };
+  for (const auto& p : candidates) {
+    if (std::filesystem::exists(p)) return p;
+  }
+  return "/app/scripts/import_local_pdf_rag.py";
+}
+
+std::string BuildLuoguCommand(const std::string& db_path,
+                              const std::string& trigger,
+                              const ImportRunOptions& options) {
+  const std::string script_path = ResolveLuoguScriptPath();
+  const int workers =
+      std::max(1, options.workers > 0 ? options.workers : EnvInt("OI_IMPORT_WORKERS", 3));
   const int llm_limit = EnvInt("OI_IMPORT_LLM_LIMIT", 0);
   const int max_problems = EnvInt("OI_IMPORT_MAX_PROBLEMS", 0);
   const bool skip_llm = EnvBool("OI_IMPORT_SKIP_LLM", false);
@@ -88,9 +126,8 @@ std::string BuildCommand(const std::string& db_path,
           : std::string("winterant/oi");
 
   std::string cmd = "python3 " + ShellQuote(script_path) + " --db-path " +
-                    ShellQuote(db_path) + " --workers " +
-                    std::to_string(workers) + " --job-trigger " +
-                    ShellQuote(trigger);
+                    ShellQuote(db_path) + " --workers " + std::to_string(workers) +
+                    " --job-trigger " + ShellQuote(trigger);
 
   if (max_problems > 0) cmd += " --max-problems " + std::to_string(max_problems);
   if (skip_llm) cmd += " --skip-llm";
@@ -107,6 +144,125 @@ std::string BuildCommand(const std::string& db_path,
   return cmd;
 }
 
+std::string BuildLocalRagCommand(const std::string& db_path,
+                                 const std::string& trigger,
+                                 const ImportRunOptions& options) {
+  const std::string script_path = ResolveLocalRagScriptPath();
+  const int workers =
+      std::max(1, options.workers > 0 ? options.workers : EnvInt("OI_IMPORT_WORKERS", 3));
+  const int target_total = std::max(
+      1,
+      options.target_total > 0 ? options.target_total : EnvInt("OI_IMPORT_TARGET_TOTAL", 5000));
+  const int attempt_multiplier =
+      std::max(2, EnvInt("OI_IMPORT_RAG_ATTEMPT_MULTIPLIER", 8));
+  const std::string pdf_dir = options.local_pdf_dir.empty()
+                                  ? EnvString("OI_LOCAL_PDF_DIR", "/data/local_pdfs")
+                                  : options.local_pdf_dir;
+
+  std::string cmd = "python3 " + ShellQuote(script_path) + " --db-path " +
+                    ShellQuote(db_path) + " --workers " + std::to_string(workers) +
+                    " --target-total " + std::to_string(target_total) +
+                    " --job-trigger " + ShellQuote(trigger) +
+                    " --max-attempt-multiplier " +
+                    std::to_string(attempt_multiplier);
+
+  if (!pdf_dir.empty()) {
+    cmd += " --pdf-dir " + ShellQuote(pdf_dir);
+  }
+
+  const char* dedupe = std::getenv("OI_IMPORT_RAG_DEDUPE_THRESHOLD");
+  if (dedupe && std::string(dedupe).size() > 0) {
+    cmd += " --dedupe-threshold " + ShellQuote(dedupe);
+  }
+
+  return cmd;
+}
+
+std::string BuildCommand(const std::string& db_path,
+                         const std::string& trigger,
+                         const ImportRunOptions& options) {
+  const std::string mode = NormalizeMode(options.mode);
+  if (mode == "local_pdf_rag") {
+    return BuildLocalRagCommand(db_path, trigger, options);
+  }
+  return BuildLuoguCommand(db_path, trigger, options);
+}
+
+std::optional<ImportRunOptions> ParseRunOptionsFromJson(const std::string& raw_json) {
+  if (raw_json.empty()) return std::nullopt;
+
+  Json::CharReaderBuilder builder;
+  Json::Value root;
+  std::string errs;
+  std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  if (!reader->parse(raw_json.data(), raw_json.data() + raw_json.size(), &root,
+                     &errs) ||
+      !root.isObject()) {
+    return std::nullopt;
+  }
+
+  ImportRunOptions opts;
+  opts.mode = NormalizeMode(root.get("mode", root.get("source", "luogu")).asString());
+  opts.clear_all_problems = root.get("clear_all_problems", false).asBool();
+  opts.workers = std::max(1, root.get("workers", 3).asInt());
+  opts.target_total = std::max(1, root.get("target_total", 5000).asInt());
+  if (root.isMember("local_pdf_dir")) {
+    opts.local_pdf_dir = root["local_pdf_dir"].asString();
+  } else if (root.isMember("pdf_dir")) {
+    opts.local_pdf_dir = root["pdf_dir"].asString();
+  }
+  return opts;
+}
+
+std::optional<ImportRunOptions> RecoverInterruptedRunOptions(const std::string& db_path) {
+  if (!EnvBool("OI_IMPORT_RESUME_ON_RESTART", true)) return std::nullopt;
+
+  sqlite3* db = nullptr;
+  if (sqlite3_open_v2(db_path.c_str(), &db, SQLITE_OPEN_READWRITE, nullptr) !=
+      SQLITE_OK) {
+    if (db) sqlite3_close(db);
+    return std::nullopt;
+  }
+  sqlite3_busy_timeout(db, 5000);
+
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT options_json FROM import_jobs WHERE status='running' ORDER BY id DESC LIMIT 1";
+  if (sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr) != SQLITE_OK) {
+    sqlite3_close(db);
+    return std::nullopt;
+  }
+
+  std::optional<ImportRunOptions> options;
+  if (sqlite3_step(stmt) == SQLITE_ROW) {
+    const unsigned char* txt = sqlite3_column_text(stmt, 0);
+    const std::string raw = txt ? reinterpret_cast<const char*>(txt) : std::string();
+    options = ParseRunOptionsFromJson(raw);
+    if (!options.has_value()) {
+      ImportRunOptions fallback;
+      fallback.mode = "luogu";
+      options = fallback;
+    }
+  }
+  sqlite3_finalize(stmt);
+
+  if (options.has_value()) {
+    sqlite3_exec(
+        db,
+        "UPDATE import_jobs "
+        "SET status='interrupted',"
+        "last_error='backend restarted, auto-resume scheduled',"
+        "finished_at=strftime('%s','now'),updated_at=strftime('%s','now') "
+        "WHERE status='running'",
+        nullptr,
+        nullptr,
+        nullptr);
+  }
+
+  sqlite3_close(db);
+  return options;
+}
+
 }  // namespace
 
 ImportRunner& ImportRunner::Instance() {
@@ -115,8 +271,21 @@ ImportRunner& ImportRunner::Instance() {
 }
 
 void ImportRunner::Configure(std::string db_path) {
-  std::lock_guard<std::mutex> lock(mu_);
-  db_path_ = std::move(db_path);
+  std::optional<ImportRunOptions> resume_opts;
+  {
+    std::lock_guard<std::mutex> lock(mu_);
+    db_path_ = std::move(db_path);
+    resume_opts = RecoverInterruptedRunOptions(db_path_);
+  }
+
+  if (resume_opts.has_value()) {
+    const bool started = TriggerAsync("resume", *resume_opts);
+    if (started) {
+      LOG_INFO << "import runner resumed interrupted job";
+    } else {
+      LOG_INFO << "import runner resume skipped";
+    }
+  }
 }
 
 bool ImportRunner::TriggerAsync(const std::string& trigger,
@@ -147,7 +316,14 @@ bool ImportRunner::TriggerAsync(const std::string& trigger,
 
 void ImportRunner::AutoStartIfEnabled() {
   if (!EnvBool("OI_IMPORT_AUTO_RUN", true)) return;
-  const bool started = TriggerAsync("auto", ImportRunOptions{});
+
+  ImportRunOptions opts;
+  opts.mode = NormalizeMode(EnvString("OI_IMPORT_AUTO_MODE", "luogu"));
+  opts.workers = std::max(1, EnvInt("OI_IMPORT_WORKERS", 3));
+  opts.target_total = std::max(1, EnvInt("OI_IMPORT_TARGET_TOTAL", 5000));
+  opts.local_pdf_dir = EnvString("OI_LOCAL_PDF_DIR", "/data/local_pdfs");
+
+  const bool started = TriggerAsync("auto", opts);
   if (started) {
     LOG_INFO << "import runner auto-started";
   } else {

backend/src/services/kb_import_runner.cc

@@ -0,0 +1,130 @@
+#include "csp/services/kb_import_runner.h"
+
+#include <drogon/drogon.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <filesystem>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+namespace csp::services {
+
+namespace {
+
+int64_t NowSec() {
+  using namespace std::chrono;
+  return duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
+}
+
+std::string ShellQuote(const std::string& text) {
+  std::string out = "'";
+  for (char c : text) {
+    if (c == '\'') {
+      out += "'\"'\"'";
+    } else {
+      out.push_back(c);
+    }
+  }
+  out.push_back('\'');
+  return out;
+}
+
+std::string ResolveScriptPath() {
+  const char* env_path = std::getenv("CSP_KB_IMPORT_SCRIPT_PATH");
+  if (env_path && std::filesystem::exists(env_path)) return env_path;
+
+  const std::vector<std::string> candidates = {
+      "/app/scripts/import_kb_learning_resources.py",
+      "scripts/import_kb_learning_resources.py",
+      "../scripts/import_kb_learning_resources.py",
+      "../../scripts/import_kb_learning_resources.py",
+  };
+  for (const auto& path : candidates) {
+    if (std::filesystem::exists(path)) return path;
+  }
+
+  return "/app/scripts/import_kb_learning_resources.py";
+}
+
+std::string BuildCommand(const std::string& db_path) {
+  const std::string script_path = ResolveScriptPath();
+  return "python3 " + ShellQuote(script_path) + " --db-path " +
+         ShellQuote(db_path) +
+         " --timeout 20 --retries 5 --max-sources-per-track 3 --max-chars-per-source 900";
+}
+
+}  // namespace
+
+KbImportRunner& KbImportRunner::Instance() {
+  static KbImportRunner inst;
+  return inst;
+}
+
+void KbImportRunner::Configure(std::string db_path) {
+  std::lock_guard<std::mutex> lock(mu_);
+  db_path_ = std::move(db_path);
+}
+
+bool KbImportRunner::TriggerAsync(const std::string& trigger) {
+  std::string command;
+  {
+    std::lock_guard<std::mutex> lock(mu_);
+    if (running_) return false;
+    if (db_path_.empty()) return false;
+
+    command = BuildCommand(db_path_);
+    running_ = true;
+    last_command_ = command;
+    last_trigger_ = trigger;
+    last_started_at_ = NowSec();
+    last_exit_code_.reset();
+  }
+
+  std::thread([this, command = std::move(command)]() {
+    LOG_INFO << "kb import started: " << command;
+    const int rc = std::system(command.c_str());
+    {
+      std::lock_guard<std::mutex> lock(mu_);
+      running_ = false;
+      last_exit_code_ = rc;
+      last_finished_at_ = NowSec();
+    }
+    LOG_INFO << "kb import finished, code=" << rc;
+  }).detach();
+
+  return true;
+}
+
+bool KbImportRunner::IsRunning() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return running_;
+}
+
+std::string KbImportRunner::LastCommand() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return last_command_;
+}
+
+std::optional<int> KbImportRunner::LastExitCode() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return last_exit_code_;
+}
+
+int64_t KbImportRunner::LastStartedAt() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return last_started_at_;
+}
+
+int64_t KbImportRunner::LastFinishedAt() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return last_finished_at_;
+}
+
+std::string KbImportRunner::LastTrigger() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return last_trigger_;
+}
+
+}  // namespace csp::services

backend/src/services/problem_solution_runner.cc

@@ -1,6 +1,13 @@
 #include "csp/services/problem_solution_runner.h"
 
+#include "csp/services/problem_workspace_service.h"
+
+#include <drogon/drogon.h>
+#include <sqlite3.h>
+
 #include <algorithm>
+#include <cctype>
+#include <chrono>
 #include <cstdlib>
 #include <filesystem>
 #include <thread>
@@ -39,6 +46,43 @@ std::string ResolveScriptPath() {
   return "/app/scripts/generate_problem_solutions.py";
 }
 
+bool EnvBool(const char* key, bool default_value) {
+  const char* raw = std::getenv(key);
+  if (!raw) return default_value;
+  std::string val(raw);
+  for (auto& c : val) c = static_cast<char>(::tolower(static_cast<unsigned char>(c)));
+  if (val == "1" || val == "true" || val == "yes" || val == "on") return true;
+  if (val == "0" || val == "false" || val == "no" || val == "off") return false;
+  return default_value;
+}
+
+int EnvInt(const char* key, int default_value) {
+  const char* raw = std::getenv(key);
+  if (!raw) return default_value;
+  try {
+    return std::stoi(raw);
+  } catch (...) {
+    return default_value;
+  }
+}
+
+bool IsDatabaseLockedMessage(const std::string& msg) {
+  return msg.find("database is locked") != std::string::npos ||
+         msg.find("database is busy") != std::string::npos;
+}
+
+std::string BuildCommand(const std::string& db_path,
+                         int64_t problem_id,
+                         int64_t job_id,
+                         int max_solutions) {
+  const std::string script_path = ResolveScriptPath();
+  const int clamped = std::max(1, std::min(5, max_solutions));
+  return "python3 " + ShellQuote(script_path) + " --db-path " +
+         ShellQuote(db_path) + " --problem-id " + std::to_string(problem_id) +
+         " --job-id " + std::to_string(job_id) + " --max-solutions " +
+         std::to_string(clamped);
+}
+
 }  // namespace
 
 ProblemSolutionRunner& ProblemSolutionRunner::Instance() {
@@ -49,38 +93,225 @@ ProblemSolutionRunner& ProblemSolutionRunner::Instance() {
 void ProblemSolutionRunner::Configure(std::string db_path) {
   std::lock_guard<std::mutex> lock(mu_);
   db_path_ = std::move(db_path);
+  RecoverQueuedJobsLocked();
+  StartWorkerIfNeededLocked();
 }
 
 bool ProblemSolutionRunner::TriggerAsync(int64_t problem_id,
                                          int64_t job_id,
                                          int max_solutions) {
-  std::string cmd;
-  {
-    std::lock_guard<std::mutex> lock(mu_);
-    if (db_path_.empty()) return false;
-    if (running_problem_ids_.count(problem_id) > 0) return false;
-    running_problem_ids_.insert(problem_id);
-
-    const std::string script_path = ResolveScriptPath();
-    const int clamped = std::max(1, std::min(5, max_solutions));
-    cmd = "python3 " + ShellQuote(script_path) + " --db-path " +
-          ShellQuote(db_path_) + " --problem-id " + std::to_string(problem_id) +
-          " --job-id " + std::to_string(job_id) + " --max-solutions " +
-          std::to_string(clamped);
-  }
-
-  std::thread([this, problem_id, command = std::move(cmd)]() {
-    std::system(command.c_str());
-    std::lock_guard<std::mutex> lock(mu_);
-    running_problem_ids_.erase(problem_id);
-  }).detach();
-
+  std::lock_guard<std::mutex> lock(mu_);
+  if (db_path_.empty()) return false;
+  Task task;
+  task.problem_id = problem_id;
+  task.job_id = job_id;
+  task.max_solutions = std::max(1, std::min(5, max_solutions));
+  queue_.push_back(task);
+  ++pending_problem_counts_[problem_id];
+  ++pending_jobs_;
+  StartWorkerIfNeededLocked();
   return true;
 }
 
+ProblemSolutionRunner::TriggerMissingSummary
+ProblemSolutionRunner::TriggerMissingAsync(db::SqliteDb& db,
+                                           int64_t created_by,
+                                           int max_solutions,
+                                           int limit) {
+  services::ProblemWorkspaceService workspace(db);
+  TriggerMissingSummary summary;
+  summary.missing_total = workspace.CountProblemsWithoutSolutions();
+  const int clamped_limit = std::max(1, std::min(200000, limit));
+  const int clamped_max_solutions = std::max(1, std::min(5, max_solutions));
+  const auto problem_ids = workspace.ListProblemIdsWithoutSolutions(
+      clamped_limit, true);
+  summary.candidate_count = static_cast<int>(problem_ids.size());
+  for (int64_t problem_id : problem_ids) {
+    int64_t job_id = 0;
+    bool created = false;
+    for (int attempt = 1; attempt <= 4; ++attempt) {
+      try {
+        job_id = workspace.CreateSolutionJob(
+            problem_id, created_by, clamped_max_solutions);
+        created = true;
+        break;
+      } catch (const std::exception& e) {
+        const std::string msg = e.what();
+        if (!IsDatabaseLockedMessage(msg) || attempt >= 4) {
+          LOG_ERROR << "create solution job failed for problem_id=" << problem_id
+                    << ", err=" << msg;
+          break;
+        }
+        std::this_thread::sleep_for(std::chrono::milliseconds(120 * attempt));
+      }
+    }
+    if (!created) continue;
+    if (TriggerAsync(problem_id, job_id, clamped_max_solutions)) {
+      ++summary.queued_count;
+    }
+  }
+  return summary;
+}
+
+void ProblemSolutionRunner::AutoStartMissingIfEnabled(db::SqliteDb& db) {
+  try {
+    if (!EnvBool("CSP_SOLUTION_AUTO_RUN_MISSING", true)) {
+      LOG_INFO << "solution auto-run missing skipped by env";
+      return;
+    }
+    const int limit = std::max(1, std::min(200000, EnvInt("CSP_SOLUTION_AUTO_LIMIT", 50000)));
+    const int max_solutions =
+        std::max(1, std::min(5, EnvInt("CSP_SOLUTION_AUTO_MAX_SOLUTIONS", 3)));
+    const int interval_sec =
+        std::max(3, std::min(300, EnvInt("CSP_SOLUTION_AUTO_INTERVAL_SEC", 12)));
+    const auto summary = TriggerMissingAsync(db, /*created_by=*/0, max_solutions, limit);
+    LOG_INFO << "solution auto-run missing queued=" << summary.queued_count
+             << ", candidates=" << summary.candidate_count
+             << ", missing_total=" << summary.missing_total
+             << ", pending_jobs=" << PendingCount();
+    StartAutoPumpIfNeeded(&db, max_solutions, limit, interval_sec);
+  } catch (const std::exception& e) {
+    LOG_ERROR << "solution auto-run missing failed: " << e.what();
+  }
+}
+
 bool ProblemSolutionRunner::IsRunning(int64_t problem_id) const {
   std::lock_guard<std::mutex> lock(mu_);
-  return running_problem_ids_.count(problem_id) > 0;
+  return pending_problem_counts_.count(problem_id) > 0;
+}
+
+size_t ProblemSolutionRunner::PendingCount() const {
+  std::lock_guard<std::mutex> lock(mu_);
+  return pending_jobs_;
+}
+
+void ProblemSolutionRunner::StartWorkerIfNeededLocked() {
+  if (worker_running_ || queue_.empty()) return;
+  worker_running_ = true;
+  std::thread([this]() { WorkerLoop(); }).detach();
+}
+
+void ProblemSolutionRunner::WorkerLoop() {
+  while (true) {
+    Task task;
+    std::string db_path;
+    {
+      std::lock_guard<std::mutex> lock(mu_);
+      if (queue_.empty()) {
+        worker_running_ = false;
+        return;
+      }
+      task = queue_.front();
+      queue_.pop_front();
+      db_path = db_path_;
+    }
+
+    const std::string cmd =
+        BuildCommand(db_path, task.problem_id, task.job_id, task.max_solutions);
+    const int rc = std::system(cmd.c_str());
+    if (rc != 0) {
+      LOG_INFO << "solution job " << task.job_id
+               << " finished with non-zero rc: " << rc;
+    }
+
+    std::lock_guard<std::mutex> lock(mu_);
+    auto it = pending_problem_counts_.find(task.problem_id);
+    if (it != pending_problem_counts_.end()) {
+      if (it->second <= 1) {
+        pending_problem_counts_.erase(it);
+      } else {
+        --it->second;
+      }
+    }
+    if (pending_jobs_ > 0) --pending_jobs_;
+  }
+}
+
+void ProblemSolutionRunner::RecoverQueuedJobsLocked() {
+  if (recovered_from_db_ || db_path_.empty()) return;
+  recovered_from_db_ = true;
+
+  sqlite3* db = nullptr;
+  if (sqlite3_open_v2(db_path_.c_str(), &db, SQLITE_OPEN_READWRITE, nullptr) !=
+      SQLITE_OK) {
+    if (db) sqlite3_close(db);
+    return;
+  }
+  sqlite3_busy_timeout(db, 5000);
+
+  sqlite3_exec(
+      db,
+      "UPDATE problem_solution_jobs "
+      "SET status='queued',progress=0,message='requeued after backend restart',"
+      "started_at=NULL,finished_at=NULL,updated_at=strftime('%s','now') "
+      "WHERE status='running'",
+      nullptr,
+      nullptr,
+      nullptr);
+
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT id,problem_id,max_solutions FROM problem_solution_jobs "
+      "WHERE status='queued' ORDER BY id ASC";
+  if (sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr) != SQLITE_OK) {
+    sqlite3_close(db);
+    return;
+  }
+
+  int recovered = 0;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    Task task;
+    task.job_id = sqlite3_column_int64(stmt, 0);
+    task.problem_id = sqlite3_column_int64(stmt, 1);
+    task.max_solutions = sqlite3_column_int(stmt, 2);
+    queue_.push_back(task);
+    ++pending_problem_counts_[task.problem_id];
+    ++pending_jobs_;
+    ++recovered;
+  }
+  sqlite3_finalize(stmt);
+  sqlite3_close(db);
+
+  if (recovered > 0) {
+    LOG_INFO << "recovered queued solution jobs: " << recovered;
+  }
+}
+
+void ProblemSolutionRunner::StartAutoPumpIfNeeded(db::SqliteDb* db,
+                                                  int max_solutions,
+                                                  int limit,
+                                                  int interval_sec) {
+  std::lock_guard<std::mutex> lock(mu_);
+  if (auto_pump_started_ || !db) return;
+  auto_pump_started_ = true;
+
+  std::thread([this, db, max_solutions, limit, interval_sec]() {
+    while (true) {
+      std::this_thread::sleep_for(std::chrono::seconds(interval_sec));
+
+      if (!EnvBool("CSP_SOLUTION_AUTO_RUN_MISSING", true)) continue;
+
+      bool idle = false;
+      {
+        std::lock_guard<std::mutex> inner(mu_);
+        idle = pending_jobs_ == 0;
+      }
+      if (!idle) continue;
+
+      try {
+        const auto summary = TriggerMissingAsync(
+            *db, /*created_by=*/0, max_solutions, limit);
+        if (summary.queued_count > 0) {
+          LOG_INFO << "solution auto-pump queued=" << summary.queued_count
+                   << ", candidates=" << summary.candidate_count
+                   << ", missing_total=" << summary.missing_total
+                   << ", pending_jobs=" << PendingCount();
+        }
+      } catch (const std::exception& e) {
+        LOG_ERROR << "solution auto-pump failed: " << e.what();
+      }
+    }
+  }).detach();
 }
 
 }  // namespace csp::services

backend/src/services/problem_workspace_service.cc

@@ -6,6 +6,7 @@
 #include <chrono>
 #include <stdexcept>
 #include <string>
+#include <utility>
 
 namespace csp::services {
 
@@ -191,6 +192,116 @@ std::optional<ProblemSolutionJob> ProblemWorkspaceService::GetLatestSolutionJob(
   return row;
 }
 
+std::vector<ProblemSolutionJob> ProblemWorkspaceService::ListRecentSolutionJobs(
+    int limit) {
+  const int capped = std::max(1, std::min(500, limit));
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT j.id,j.problem_id,j.status,j.progress,j.message,j.created_by,j.max_solutions,"
+      "j.created_at,j.started_at,j.finished_at,j.updated_at,p.title "
+      "FROM problem_solution_jobs j "
+      "LEFT JOIN problems p ON p.id=j.problem_id "
+      "ORDER BY j.id DESC LIMIT ?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare recent solution jobs");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, capped), db, "bind recent jobs limit");
+
+  std::vector<ProblemSolutionJob> rows;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    auto row = ReadSolutionJob(stmt);
+    row.problem_title = ColText(stmt, 11);
+    rows.push_back(std::move(row));
+  }
+  sqlite3_finalize(stmt);
+  return rows;
+}
+
+std::vector<ProblemSolutionJob> ProblemWorkspaceService::ListSolutionJobsByStatus(
+    const std::string& status,
+    int limit) {
+  const int capped = std::max(1, std::min(1000, limit));
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const bool queued = status == "queued";
+  const char* sql = queued
+                        ? "SELECT j.id,j.problem_id,j.status,j.progress,j.message,j.created_by,j.max_solutions,"
+                          "j.created_at,j.started_at,j.finished_at,j.updated_at,p.title "
+                          "FROM problem_solution_jobs j "
+                          "LEFT JOIN problems p ON p.id=j.problem_id "
+                          "WHERE j.status=? "
+                          "ORDER BY j.id ASC LIMIT ?"
+                        : "SELECT j.id,j.problem_id,j.status,j.progress,j.message,j.created_by,j.max_solutions,"
+                          "j.created_at,j.started_at,j.finished_at,j.updated_at,p.title "
+                          "FROM problem_solution_jobs j "
+                          "LEFT JOIN problems p ON p.id=j.problem_id "
+                          "WHERE j.status=? "
+                          "ORDER BY j.updated_at DESC, j.id DESC LIMIT ?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare solution jobs by status");
+  CheckSqlite(sqlite3_bind_text(stmt, 1, status.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind solution jobs status");
+  CheckSqlite(sqlite3_bind_int(stmt, 2, capped), db, "bind solution jobs limit");
+
+  std::vector<ProblemSolutionJob> rows;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    auto row = ReadSolutionJob(stmt);
+    row.problem_title = ColText(stmt, 11);
+    rows.push_back(std::move(row));
+  }
+  sqlite3_finalize(stmt);
+  return rows;
+}
+
+int ProblemWorkspaceService::CountProblemsWithoutSolutions() {
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT COUNT(*) "
+      "FROM problems p "
+      "WHERE NOT EXISTS (SELECT 1 FROM problem_solutions s WHERE s.problem_id=p.id)";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare count missing solutions");
+  CheckSqlite(sqlite3_step(stmt), db, "step count missing solutions");
+  const int count = sqlite3_column_int(stmt, 0);
+  sqlite3_finalize(stmt);
+  return count;
+}
+
+std::vector<int64_t> ProblemWorkspaceService::ListProblemIdsWithoutSolutions(
+    int limit,
+    bool exclude_queued_or_running_jobs) {
+  const int capped = std::max(1, std::min(200000, limit));
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql_all =
+      "SELECT p.id "
+      "FROM problems p "
+      "WHERE NOT EXISTS (SELECT 1 FROM problem_solutions s WHERE s.problem_id=p.id) "
+      "ORDER BY p.id ASC LIMIT ?";
+  const char* sql_skip_busy =
+      "SELECT p.id "
+      "FROM problems p "
+      "WHERE NOT EXISTS (SELECT 1 FROM problem_solutions s WHERE s.problem_id=p.id) "
+      "AND NOT EXISTS ("
+      "  SELECT 1 FROM problem_solution_jobs j "
+      "  WHERE j.problem_id=p.id AND j.status IN ('queued','running')"
+      ") "
+      "ORDER BY p.id ASC LIMIT ?";
+  const char* sql = exclude_queued_or_running_jobs ? sql_skip_busy : sql_all;
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare list missing solution problem ids");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, capped), db,
+              "bind list missing solution problem ids limit");
+
+  std::vector<int64_t> rows;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    rows.push_back(sqlite3_column_int64(stmt, 0));
+  }
+  sqlite3_finalize(stmt);
+  return rows;
+}
+
 std::vector<ProblemSolution> ProblemWorkspaceService::ListSolutions(int64_t problem_id) {
   sqlite3* db = db_.raw();
   sqlite3_stmt* stmt = nullptr;

backend/src/services/redeem_service.cc

@@ -0,0 +1,360 @@
+#include "csp/services/redeem_service.h"
+
+#include <sqlite3.h>
+
+#include <algorithm>
+#include <chrono>
+#include <cctype>
+#include <stdexcept>
+#include <string>
+#include <utility>
+
+namespace csp::services {
+
+namespace {
+
+int64_t NowSec() {
+  using namespace std::chrono;
+  return duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
+}
+
+void CheckSqlite(int rc, sqlite3* db, const char* what) {
+  if (rc == SQLITE_OK || rc == SQLITE_ROW || rc == SQLITE_DONE) return;
+  throw std::runtime_error(std::string(what) + ": " + sqlite3_errmsg(db));
+}
+
+std::string ColText(sqlite3_stmt* stmt, int col) {
+  const unsigned char* txt = sqlite3_column_text(stmt, col);
+  return txt ? reinterpret_cast<const char*>(txt) : std::string();
+}
+
+RedeemItem ReadItem(sqlite3_stmt* stmt) {
+  RedeemItem item;
+  item.id = sqlite3_column_int64(stmt, 0);
+  item.name = ColText(stmt, 1);
+  item.description = ColText(stmt, 2);
+  item.unit_label = ColText(stmt, 3);
+  item.holiday_cost = sqlite3_column_int(stmt, 4);
+  item.studyday_cost = sqlite3_column_int(stmt, 5);
+  item.is_active = sqlite3_column_int(stmt, 6) != 0;
+  item.is_global = sqlite3_column_int(stmt, 7) != 0;
+  item.created_by = sqlite3_column_int64(stmt, 8);
+  item.created_at = sqlite3_column_int64(stmt, 9);
+  item.updated_at = sqlite3_column_int64(stmt, 10);
+  return item;
+}
+
+RedeemRecord ReadRecord(sqlite3_stmt* stmt) {
+  RedeemRecord row;
+  row.id = sqlite3_column_int64(stmt, 0);
+  row.user_id = sqlite3_column_int64(stmt, 1);
+  row.item_id = sqlite3_column_int64(stmt, 2);
+  row.item_name = ColText(stmt, 3);
+  row.quantity = sqlite3_column_int(stmt, 4);
+  row.day_type = ColText(stmt, 5);
+  row.unit_cost = sqlite3_column_int(stmt, 6);
+  row.total_cost = sqlite3_column_int(stmt, 7);
+  row.note = ColText(stmt, 8);
+  row.created_at = sqlite3_column_int64(stmt, 9);
+  row.username = ColText(stmt, 10);
+  return row;
+}
+
+std::string NormalizeDayType(std::string day_type) {
+  for (auto& c : day_type) {
+    c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
+  }
+  if (day_type == "holiday" || day_type == "vacation" || day_type == "weekend") {
+    return "holiday";
+  }
+  return "studyday";
+}
+
+void ValidateItemWrite(const RedeemItemWrite& input) {
+  if (input.name.empty()) throw std::runtime_error("item name required");
+  if (input.name.size() > 120) throw std::runtime_error("item name too long");
+  if (input.description.size() > 1000) throw std::runtime_error("description too long");
+  if (input.unit_label.empty() || input.unit_label.size() > 20) {
+    throw std::runtime_error("invalid unit label");
+  }
+  if (input.holiday_cost < 0 || input.studyday_cost < 0) {
+    throw std::runtime_error("cost must be >= 0");
+  }
+}
+
+int QueryUserRating(sqlite3* db, int64_t user_id) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "SELECT rating FROM users WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare query user rating");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, user_id), db, "bind user_id");
+  if (sqlite3_step(stmt) != SQLITE_ROW) {
+    sqlite3_finalize(stmt);
+    throw std::runtime_error("user not found");
+  }
+  const int rating = sqlite3_column_int(stmt, 0);
+  sqlite3_finalize(stmt);
+  return rating;
+}
+
+void DeductUserRating(sqlite3* db, int64_t user_id, int delta) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "UPDATE users SET rating=rating-? WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare deduct user rating");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, delta), db, "bind delta");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_step(stmt), db, "exec deduct user rating");
+  sqlite3_finalize(stmt);
+}
+
+}  // namespace
+
+std::vector<RedeemItem> RedeemService::ListItems(bool include_inactive) {
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql_all =
+      "SELECT id,name,description,unit_label,holiday_cost,studyday_cost,is_active,is_global,created_by,created_at,updated_at "
+      "FROM redeem_items ORDER BY id ASC";
+  const char* sql_active =
+      "SELECT id,name,description,unit_label,holiday_cost,studyday_cost,is_active,is_global,created_by,created_at,updated_at "
+      "FROM redeem_items WHERE is_active=1 ORDER BY id ASC";
+  CheckSqlite(sqlite3_prepare_v2(db, include_inactive ? sql_all : sql_active, -1, &stmt, nullptr),
+              db,
+              "prepare list redeem items");
+
+  std::vector<RedeemItem> out;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    out.push_back(ReadItem(stmt));
+  }
+  sqlite3_finalize(stmt);
+  return out;
+}
+
+std::optional<RedeemItem> RedeemService::GetItemById(int64_t item_id) {
+  if (item_id <= 0) return std::nullopt;
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT id,name,description,unit_label,holiday_cost,studyday_cost,is_active,is_global,created_by,created_at,updated_at "
+      "FROM redeem_items WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare get redeem item");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, item_id), db, "bind item_id");
+  if (sqlite3_step(stmt) != SQLITE_ROW) {
+    sqlite3_finalize(stmt);
+    return std::nullopt;
+  }
+  auto item = ReadItem(stmt);
+  sqlite3_finalize(stmt);
+  return item;
+}
+
+RedeemItem RedeemService::CreateItem(int64_t admin_user_id, const RedeemItemWrite& input) {
+  ValidateItemWrite(input);
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const int64_t now = NowSec();
+  const char* sql =
+      "INSERT INTO redeem_items(name,description,unit_label,holiday_cost,studyday_cost,is_active,is_global,created_by,created_at,updated_at) "
+      "VALUES(?,?,?,?,?,?,?,?,?,?)";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare create redeem item");
+  CheckSqlite(sqlite3_bind_text(stmt, 1, input.name.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind name");
+  CheckSqlite(sqlite3_bind_text(stmt, 2, input.description.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind description");
+  CheckSqlite(sqlite3_bind_text(stmt, 3, input.unit_label.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind unit_label");
+  CheckSqlite(sqlite3_bind_int(stmt, 4, input.holiday_cost), db, "bind holiday_cost");
+  CheckSqlite(sqlite3_bind_int(stmt, 5, input.studyday_cost), db, "bind studyday_cost");
+  CheckSqlite(sqlite3_bind_int(stmt, 6, input.is_active ? 1 : 0), db, "bind is_active");
+  CheckSqlite(sqlite3_bind_int(stmt, 7, input.is_global ? 1 : 0), db, "bind is_global");
+  CheckSqlite(sqlite3_bind_int64(stmt, 8, admin_user_id), db, "bind created_by");
+  CheckSqlite(sqlite3_bind_int64(stmt, 9, now), db, "bind created_at");
+  CheckSqlite(sqlite3_bind_int64(stmt, 10, now), db, "bind updated_at");
+  CheckSqlite(sqlite3_step(stmt), db, "create redeem item");
+  sqlite3_finalize(stmt);
+
+  const auto item = GetItemById(sqlite3_last_insert_rowid(db));
+  if (!item.has_value()) throw std::runtime_error("create redeem item failed");
+  return *item;
+}
+
+RedeemItem RedeemService::UpdateItem(int64_t item_id, const RedeemItemWrite& input) {
+  ValidateItemWrite(input);
+  if (item_id <= 0) throw std::runtime_error("invalid item_id");
+
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const int64_t now = NowSec();
+  const char* sql =
+      "UPDATE redeem_items "
+      "SET name=?,description=?,unit_label=?,holiday_cost=?,studyday_cost=?,is_active=?,is_global=?,updated_at=? "
+      "WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare update redeem item");
+  CheckSqlite(sqlite3_bind_text(stmt, 1, input.name.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind name");
+  CheckSqlite(sqlite3_bind_text(stmt, 2, input.description.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind description");
+  CheckSqlite(sqlite3_bind_text(stmt, 3, input.unit_label.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind unit_label");
+  CheckSqlite(sqlite3_bind_int(stmt, 4, input.holiday_cost), db, "bind holiday_cost");
+  CheckSqlite(sqlite3_bind_int(stmt, 5, input.studyday_cost), db, "bind studyday_cost");
+  CheckSqlite(sqlite3_bind_int(stmt, 6, input.is_active ? 1 : 0), db, "bind is_active");
+  CheckSqlite(sqlite3_bind_int(stmt, 7, input.is_global ? 1 : 0), db, "bind is_global");
+  CheckSqlite(sqlite3_bind_int64(stmt, 8, now), db, "bind updated_at");
+  CheckSqlite(sqlite3_bind_int64(stmt, 9, item_id), db, "bind item_id");
+  CheckSqlite(sqlite3_step(stmt), db, "update redeem item");
+  sqlite3_finalize(stmt);
+  if (sqlite3_changes(db) <= 0) throw std::runtime_error("redeem item not found");
+
+  const auto item = GetItemById(item_id);
+  if (!item.has_value()) throw std::runtime_error("reload redeem item failed");
+  return *item;
+}
+
+void RedeemService::DeactivateItem(int64_t item_id) {
+  if (item_id <= 0) throw std::runtime_error("invalid item_id");
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "UPDATE redeem_items SET is_active=0,updated_at=? WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare deactivate redeem item");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, NowSec()), db, "bind updated_at");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, item_id), db, "bind item_id");
+  CheckSqlite(sqlite3_step(stmt), db, "deactivate redeem item");
+  sqlite3_finalize(stmt);
+  if (sqlite3_changes(db) <= 0) throw std::runtime_error("redeem item not found");
+}
+
+std::vector<RedeemRecord> RedeemService::ListRecordsByUser(int64_t user_id, int limit) {
+  return ListRecordsAll(user_id, limit);
+}
+
+std::vector<RedeemRecord> RedeemService::ListRecordsAll(std::optional<int64_t> user_id,
+                                                        int limit) {
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const int safe_limit = std::max(1, std::min(500, limit));
+
+  const char* sql_all =
+      "SELECT r.id,r.user_id,r.item_id,r.item_name,r.quantity,r.day_type,r.unit_cost,r.total_cost,r.note,r.created_at,"
+      "COALESCE(u.username,'') "
+      "FROM redeem_records r LEFT JOIN users u ON u.id=r.user_id "
+      "ORDER BY r.id DESC LIMIT ?";
+  const char* sql_by_user =
+      "SELECT r.id,r.user_id,r.item_id,r.item_name,r.quantity,r.day_type,r.unit_cost,r.total_cost,r.note,r.created_at,"
+      "COALESCE(u.username,'') "
+      "FROM redeem_records r LEFT JOIN users u ON u.id=r.user_id "
+      "WHERE r.user_id=? ORDER BY r.id DESC LIMIT ?";
+
+  CheckSqlite(sqlite3_prepare_v2(db, user_id.has_value() ? sql_by_user : sql_all, -1, &stmt, nullptr),
+              db,
+              "prepare list redeem records");
+
+  if (user_id.has_value()) {
+    CheckSqlite(sqlite3_bind_int64(stmt, 1, *user_id), db, "bind user_id");
+    CheckSqlite(sqlite3_bind_int(stmt, 2, safe_limit), db, "bind limit");
+  } else {
+    CheckSqlite(sqlite3_bind_int(stmt, 1, safe_limit), db, "bind limit");
+  }
+
+  std::vector<RedeemRecord> out;
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    out.push_back(ReadRecord(stmt));
+  }
+  sqlite3_finalize(stmt);
+  return out;
+}
+
+RedeemRecord RedeemService::Redeem(const RedeemRequest& request) {
+  if (request.user_id <= 0 || request.item_id <= 0) {
+    throw std::runtime_error("invalid user_id/item_id");
+  }
+  if (request.quantity <= 0 || request.quantity > 24) {
+    throw std::runtime_error("quantity must be in [1,24]");
+  }
+  if (request.note.size() > 1000) {
+    throw std::runtime_error("note too long");
+  }
+
+  sqlite3* db = db_.raw();
+  db_.Exec("BEGIN IMMEDIATE");
+  bool committed = false;
+  try {
+    const auto item = GetItemById(request.item_id);
+    if (!item.has_value()) {
+      throw std::runtime_error("redeem item not found");
+    }
+    if (!item->is_active) {
+      throw std::runtime_error("redeem item is inactive");
+    }
+
+    const std::string day_type = NormalizeDayType(request.day_type);
+    const int unit_cost = day_type == "holiday" ? item->holiday_cost : item->studyday_cost;
+    const int total_cost = unit_cost * request.quantity;
+
+    const int current_rating = QueryUserRating(db, request.user_id);
+    if (current_rating < total_cost) {
+      throw std::runtime_error("rating not enough");
+    }
+
+    DeductUserRating(db, request.user_id, total_cost);
+
+    sqlite3_stmt* stmt = nullptr;
+    const int64_t now = NowSec();
+    const char* sql =
+        "INSERT INTO redeem_records(user_id,item_id,item_name,quantity,day_type,unit_cost,total_cost,note,created_at) "
+        "VALUES(?,?,?,?,?,?,?,?,?)";
+    CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+                "prepare insert redeem record");
+    CheckSqlite(sqlite3_bind_int64(stmt, 1, request.user_id), db, "bind user_id");
+    CheckSqlite(sqlite3_bind_int64(stmt, 2, request.item_id), db, "bind item_id");
+    CheckSqlite(sqlite3_bind_text(stmt, 3, item->name.c_str(), -1, SQLITE_TRANSIENT), db,
+                "bind item_name");
+    CheckSqlite(sqlite3_bind_int(stmt, 4, request.quantity), db, "bind quantity");
+    CheckSqlite(sqlite3_bind_text(stmt, 5, day_type.c_str(), -1, SQLITE_TRANSIENT), db,
+                "bind day_type");
+    CheckSqlite(sqlite3_bind_int(stmt, 6, unit_cost), db, "bind unit_cost");
+    CheckSqlite(sqlite3_bind_int(stmt, 7, total_cost), db, "bind total_cost");
+    CheckSqlite(sqlite3_bind_text(stmt, 8, request.note.c_str(), -1, SQLITE_TRANSIENT), db,
+                "bind note");
+    CheckSqlite(sqlite3_bind_int64(stmt, 9, now), db, "bind created_at");
+    CheckSqlite(sqlite3_step(stmt), db, "insert redeem record");
+    sqlite3_finalize(stmt);
+
+    const int64_t record_id = sqlite3_last_insert_rowid(db);
+    db_.Exec("COMMIT");
+    committed = true;
+
+    auto rows = ListRecordsAll(request.user_id, 1);
+    if (!rows.empty() && rows.front().id == record_id) {
+      return rows.front();
+    }
+
+    RedeemRecord fallback;
+    fallback.id = record_id;
+    fallback.user_id = request.user_id;
+    fallback.item_id = request.item_id;
+    fallback.item_name = item->name;
+    fallback.quantity = request.quantity;
+    fallback.day_type = day_type;
+    fallback.unit_cost = unit_cost;
+    fallback.total_cost = total_cost;
+    fallback.note = request.note;
+    fallback.created_at = now;
+    return fallback;
+  } catch (...) {
+    if (!committed) {
+      try {
+        db_.Exec("ROLLBACK");
+      } catch (...) {
+      }
+    }
+    throw;
+  }
+}
+
+}  // namespace csp::services

backend/src/services/solution_access_service.cc

@@ -0,0 +1,203 @@
+#include "csp/services/solution_access_service.h"
+
+#include <sqlite3.h>
+
+#include <chrono>
+#include <ctime>
+#include <stdexcept>
+#include <string>
+
+namespace csp::services {
+
+namespace {
+
+constexpr int kViewCost = 2;
+
+int64_t NowSec() {
+  using namespace std::chrono;
+  return duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
+}
+
+void CheckSqlite(int rc, sqlite3* db, const char* what) {
+  if (rc == SQLITE_OK || rc == SQLITE_ROW || rc == SQLITE_DONE) return;
+  throw std::runtime_error(std::string(what) + ": " + sqlite3_errmsg(db));
+}
+
+std::string ColText(sqlite3_stmt* stmt, int col) {
+  const unsigned char* txt = sqlite3_column_text(stmt, col);
+  return txt ? reinterpret_cast<const char*>(txt) : std::string();
+}
+
+std::string BuildDayKeyChina(int64_t ts_sec) {
+  const std::time_t shifted = static_cast<std::time_t>(ts_sec + 8 * 3600);
+  std::tm tm {};
+  gmtime_r(&shifted, &tm);
+  char buf[16] = {0};
+  std::strftime(buf, sizeof(buf), "%Y-%m-%d", &tm);
+  return std::string(buf);
+}
+
+int QueryRating(sqlite3* db, int64_t user_id) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "SELECT rating FROM users WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare query rating");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, user_id), db, "bind user_id");
+  if (sqlite3_step(stmt) != SQLITE_ROW) {
+    sqlite3_finalize(stmt);
+    throw std::runtime_error("user not found");
+  }
+  const int rating = sqlite3_column_int(stmt, 0);
+  sqlite3_finalize(stmt);
+  return rating;
+}
+
+int QueryDailyUsage(sqlite3* db, int64_t user_id, const std::string& day_key) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT COUNT(1) FROM problem_solution_view_logs WHERE user_id=? AND day_key=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare query daily usage");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_bind_text(stmt, 2, day_key.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind day_key");
+  CheckSqlite(sqlite3_step(stmt), db, "step query daily usage");
+  const int used = sqlite3_column_int(stmt, 0);
+  sqlite3_finalize(stmt);
+  return used;
+}
+
+void InsertViewLog(sqlite3* db,
+                   int64_t user_id,
+                   int64_t problem_id,
+                   const std::string& day_key,
+                   int64_t viewed_at,
+                   bool charged,
+                   int cost) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "INSERT INTO problem_solution_view_logs(user_id,problem_id,day_key,viewed_at,charged,cost,created_at) "
+      "VALUES(?,?,?,?,?,?,?)";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare insert solution view log");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, problem_id), db, "bind problem_id");
+  CheckSqlite(sqlite3_bind_text(stmt, 3, day_key.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind day_key");
+  CheckSqlite(sqlite3_bind_int64(stmt, 4, viewed_at), db, "bind viewed_at");
+  CheckSqlite(sqlite3_bind_int(stmt, 5, charged ? 1 : 0), db, "bind charged");
+  CheckSqlite(sqlite3_bind_int(stmt, 6, cost), db, "bind cost");
+  CheckSqlite(sqlite3_bind_int64(stmt, 7, viewed_at), db, "bind created_at");
+  CheckSqlite(sqlite3_step(stmt), db, "insert solution view log");
+  sqlite3_finalize(stmt);
+}
+
+void DeductRating(sqlite3* db, int64_t user_id, int cost) {
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "UPDATE users SET rating=rating-? WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare deduct rating");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, cost), db, "bind cost");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_step(stmt), db, "deduct rating");
+  sqlite3_finalize(stmt);
+}
+
+}  // namespace
+
+SolutionViewChargeResult SolutionAccessService::ConsumeSolutionView(
+    int64_t user_id,
+    int64_t problem_id) {
+  if (user_id <= 0 || problem_id <= 0) {
+    throw std::runtime_error("invalid user_id/problem_id");
+  }
+
+  sqlite3* db = db_.raw();
+  const int64_t now = NowSec();
+  const std::string day_key = BuildDayKeyChina(now);
+
+  db_.Exec("BEGIN IMMEDIATE");
+  bool committed = false;
+  try {
+    SolutionViewChargeResult result;
+    result.day_key = day_key;
+    result.viewed_at = now;
+
+    const int used_before = QueryDailyUsage(db, user_id, day_key);
+    result.daily_used_count = used_before;
+    const int rating_before = QueryRating(db, user_id);
+    result.rating_before = rating_before;
+
+    if (used_before <= 0) {
+      result.daily_free = true;
+      result.charged = false;
+      result.cost = 0;
+      result.rating_after = rating_before;
+    } else {
+      if (rating_before < kViewCost) {
+        result.granted = false;
+        result.charged = false;
+        result.cost = kViewCost;
+        result.rating_after = rating_before;
+        result.deny_reason = "rating not enough";
+        db_.Exec("ROLLBACK");
+        return result;
+      }
+      result.daily_free = false;
+      result.charged = true;
+      result.cost = kViewCost;
+      result.rating_after = rating_before - kViewCost;
+      DeductRating(db, user_id, kViewCost);
+    }
+
+    InsertViewLog(db,
+                  user_id,
+                  problem_id,
+                  day_key,
+                  now,
+                  result.charged,
+                  result.cost);
+    result.daily_used_count = used_before + 1;
+
+    db_.Exec("COMMIT");
+    committed = true;
+    return result;
+  } catch (...) {
+    if (!committed) {
+      try {
+        db_.Exec("ROLLBACK");
+      } catch (...) {
+      }
+    }
+    throw;
+  }
+}
+
+SolutionViewStats SolutionAccessService::QueryUserProblemViewStats(
+    int64_t user_id,
+    int64_t problem_id) {
+  SolutionViewStats stats;
+  if (user_id <= 0 || problem_id <= 0) return stats;
+
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT COUNT(1),COALESCE(SUM(cost),0),MAX(viewed_at) "
+      "FROM problem_solution_view_logs WHERE user_id=? AND problem_id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare query solution view stats");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, problem_id), db, "bind problem_id");
+
+  CheckSqlite(sqlite3_step(stmt), db, "step query solution view stats");
+  stats.total_views = sqlite3_column_int(stmt, 0);
+  stats.total_cost = sqlite3_column_int(stmt, 1);
+  if (sqlite3_column_type(stmt, 2) != SQLITE_NULL) {
+    stats.last_viewed_at = sqlite3_column_int64(stmt, 2);
+  }
+  stats.has_viewed = stats.total_views > 0;
+  sqlite3_finalize(stmt);
+  return stats;
+}
+
+}  // namespace csp::services

backend/src/services/submission_feedback_service.cc

@@ -0,0 +1,228 @@
+#include "csp/services/submission_feedback_service.h"
+
+#include "csp/domain/enum_strings.h"
+#include "csp/services/crypto.h"
+
+#include <json/json.h>
+#include <sqlite3.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <cstdio>
+#include <filesystem>
+#include <fstream>
+#include <memory>
+#include <stdexcept>
+#include <string>
+#include <sys/wait.h>
+#include <vector>
+
+namespace csp::services {
+
+namespace {
+
+int64_t NowSec() {
+  using namespace std::chrono;
+  return duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
+}
+
+void CheckSqlite(int rc, sqlite3* db, const char* what) {
+  if (rc == SQLITE_OK || rc == SQLITE_ROW || rc == SQLITE_DONE) return;
+  throw std::runtime_error(std::string(what) + ": " + sqlite3_errmsg(db));
+}
+
+std::string ColText(sqlite3_stmt* stmt, int col) {
+  const unsigned char* txt = sqlite3_column_text(stmt, col);
+  return txt ? reinterpret_cast<const char*>(txt) : std::string();
+}
+
+std::string ShellQuote(const std::string& text) {
+  std::string out = "'";
+  for (char c : text) {
+    if (c == '\'') {
+      out += "'\"'\"'";
+    } else {
+      out.push_back(c);
+    }
+  }
+  out.push_back('\'');
+  return out;
+}
+
+std::string ResolveScriptPath() {
+  const char* env_path = std::getenv("CSP_SUBMISSION_ANALYSIS_SCRIPT_PATH");
+  if (env_path && std::filesystem::exists(env_path)) return env_path;
+
+  const std::vector<std::string> candidates = {
+      "/app/scripts/analyze_submission_feedback.py",
+      "scripts/analyze_submission_feedback.py",
+      "../scripts/analyze_submission_feedback.py",
+      "../../scripts/analyze_submission_feedback.py",
+  };
+  for (const auto& path : candidates) {
+    if (std::filesystem::exists(path)) return path;
+  }
+  return "/app/scripts/analyze_submission_feedback.py";
+}
+
+int ExitCodeFromSystem(int rc) {
+  if (rc == -1) return -1;
+  if (WIFEXITED(rc)) return WEXITSTATUS(rc);
+  if (WIFSIGNALED(rc)) return 128 + WTERMSIG(rc);
+  return -1;
+}
+
+SubmissionFeedback ReadSubmissionFeedback(sqlite3_stmt* stmt) {
+  SubmissionFeedback row;
+  row.submission_id = sqlite3_column_int64(stmt, 0);
+  row.feedback_md = ColText(stmt, 1);
+  row.links_json = ColText(stmt, 2);
+  row.model_name = ColText(stmt, 3);
+  row.status = ColText(stmt, 4);
+  row.created_at = sqlite3_column_int64(stmt, 5);
+  row.updated_at = sqlite3_column_int64(stmt, 6);
+  return row;
+}
+
+std::string JsonToString(const Json::Value& value) {
+  Json::StreamWriterBuilder builder;
+  builder["indentation"] = "";
+  return Json::writeString(builder, value);
+}
+
+}  // namespace
+
+std::optional<SubmissionFeedback> SubmissionFeedbackService::GetBySubmissionId(
+    int64_t submission_id) {
+  if (submission_id <= 0) return std::nullopt;
+
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT submission_id,feedback_md,links_json,model_name,status,created_at,updated_at "
+      "FROM submission_feedback WHERE submission_id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare get submission feedback");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, submission_id), db,
+              "bind submission_id");
+
+  if (sqlite3_step(stmt) != SQLITE_ROW) {
+    sqlite3_finalize(stmt);
+    return std::nullopt;
+  }
+
+  auto row = ReadSubmissionFeedback(stmt);
+  sqlite3_finalize(stmt);
+  return row;
+}
+
+SubmissionFeedback SubmissionFeedbackService::GenerateAndSave(
+    const domain::Submission& submission,
+    const domain::Problem& problem,
+    bool force_refresh) {
+  if (!force_refresh) {
+    if (const auto existing = GetBySubmissionId(submission.id); existing.has_value()) {
+      return *existing;
+    }
+  }
+
+  Json::Value input;
+  input["submission_id"] = Json::Int64(submission.id);
+  input["problem_id"] = Json::Int64(problem.id);
+  input["problem_title"] = problem.title;
+  input["problem_statement"] = problem.statement_md;
+  input["sample_input"] = problem.sample_input;
+  input["sample_output"] = problem.sample_output;
+  input["status"] = domain::ToString(submission.status);
+  input["score"] = submission.score;
+  input["time_ms"] = submission.time_ms;
+  input["language"] = domain::ToString(submission.language);
+  input["code"] = submission.code;
+  input["compile_log"] = submission.compile_log;
+  input["runtime_log"] = submission.runtime_log;
+
+  namespace fs = std::filesystem;
+  const fs::path temp_file =
+      fs::path("/tmp") / ("csp_submission_feedback_" + crypto::RandomHex(8) + ".json");
+  {
+    std::ofstream out(temp_file, std::ios::out | std::ios::binary | std::ios::trunc);
+    if (!out) throw std::runtime_error("failed to create temp input file");
+    out << JsonToString(input);
+  }
+
+  const std::string script = ResolveScriptPath();
+  const std::string cmd =
+      "/usr/bin/timeout 45s python3 " + ShellQuote(script) + " --input-file " +
+      ShellQuote(temp_file.string()) + " 2>&1";
+
+  std::string output;
+  int exit_code = -1;
+  {
+    FILE* pipe = popen(cmd.c_str(), "r");
+    if (!pipe) {
+      fs::remove(temp_file);
+      throw std::runtime_error("failed to start feedback script");
+    }
+    char buffer[4096];
+    while (fgets(buffer, sizeof(buffer), pipe) != nullptr) {
+      output += buffer;
+    }
+    exit_code = ExitCodeFromSystem(pclose(pipe));
+  }
+  fs::remove(temp_file);
+
+  if (exit_code != 0) {
+    throw std::runtime_error("feedback script failed: " + output);
+  }
+
+  Json::CharReaderBuilder builder;
+  Json::Value parsed;
+  std::string errs;
+  std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  if (!reader->parse(output.data(), output.data() + output.size(), &parsed, &errs) ||
+      !parsed.isObject()) {
+    throw std::runtime_error("feedback script returned invalid json");
+  }
+
+  const std::string feedback_md = parsed.get("feedback_md", "").asString();
+  const std::string model_name = parsed.get("model_name", "").asString();
+  const std::string status = parsed.get("status", "ready").asString();
+  const Json::Value links = parsed.isMember("links") ? parsed["links"] : Json::Value(Json::arrayValue);
+  const std::string links_json = JsonToString(links);
+
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const int64_t now = NowSec();
+  const char* upsert_sql =
+      "INSERT INTO submission_feedback(submission_id,feedback_md,links_json,model_name,status,created_at,updated_at) "
+      "VALUES(?,?,?,?,?,?,?) "
+      "ON CONFLICT(submission_id) DO UPDATE SET "
+      "feedback_md=excluded.feedback_md,"
+      "links_json=excluded.links_json,"
+      "model_name=excluded.model_name,"
+      "status=excluded.status,"
+      "updated_at=excluded.updated_at";
+  CheckSqlite(sqlite3_prepare_v2(db, upsert_sql, -1, &stmt, nullptr), db,
+              "prepare upsert submission feedback");
+  CheckSqlite(sqlite3_bind_int64(stmt, 1, submission.id), db, "bind submission_id");
+  CheckSqlite(sqlite3_bind_text(stmt, 2, feedback_md.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind feedback_md");
+  CheckSqlite(sqlite3_bind_text(stmt, 3, links_json.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind links_json");
+  CheckSqlite(sqlite3_bind_text(stmt, 4, model_name.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind model_name");
+  CheckSqlite(sqlite3_bind_text(stmt, 5, status.c_str(), -1, SQLITE_TRANSIENT), db,
+              "bind status");
+  CheckSqlite(sqlite3_bind_int64(stmt, 6, now), db, "bind created_at");
+  CheckSqlite(sqlite3_bind_int64(stmt, 7, now), db, "bind updated_at");
+  CheckSqlite(sqlite3_step(stmt), db, "upsert submission feedback");
+  sqlite3_finalize(stmt);
+
+  const auto saved = GetBySubmissionId(submission.id);
+  if (!saved.has_value()) {
+    throw std::runtime_error("submission feedback saved but reload failed");
+  }
+  return *saved;
+}
+
+}  // namespace csp::services

backend/src/services/submission_service.cc

@@ -341,12 +341,16 @@ std::vector<domain::Submission> SubmissionService::List(std::optional<int64_t> u
   sqlite3_stmt* stmt = nullptr;
 
   std::string sql =
-      "SELECT id,user_id,problem_id,contest_id,language,code,status,score,time_ms,memory_kb,compile_log,runtime_log,created_at "
-      "FROM submissions WHERE 1=1 ";
-  if (user_id.has_value()) sql += "AND user_id=? ";
-  if (problem_id.has_value()) sql += "AND problem_id=? ";
-  if (contest_id.has_value()) sql += "AND contest_id=? ";
-  sql += "ORDER BY id DESC LIMIT ? OFFSET ?";
+      "SELECT s.id,s.user_id,s.problem_id,s.contest_id,s.language,s.code,s.status,s.score,s.time_ms,s.memory_kb,s.compile_log,s.runtime_log,s.created_at,"
+      "CASE WHEN s.status='AC' AND NOT EXISTS ("
+      "  SELECT 1 FROM submissions s2 "
+      "  WHERE s2.user_id=s.user_id AND s2.problem_id=s.problem_id AND s2.status='AC' AND s2.id<s.id"
+      ") THEN 2 ELSE 0 END AS rating_delta "
+      "FROM submissions s WHERE 1=1 ";
+  if (user_id.has_value()) sql += "AND s.user_id=? ";
+  if (problem_id.has_value()) sql += "AND s.problem_id=? ";
+  if (contest_id.has_value()) sql += "AND s.contest_id=? ";
+  sql += "ORDER BY s.id DESC LIMIT ? OFFSET ?";
 
   CheckSqlite(sqlite3_prepare_v2(db, sql.c_str(), -1, &stmt, nullptr), db,
               "prepare list submissions");
@@ -385,6 +389,7 @@ std::vector<domain::Submission> SubmissionService::List(std::optional<int64_t> u
     s.compile_log = ColText(stmt, 10);
     s.runtime_log = ColText(stmt, 11);
     s.created_at = sqlite3_column_int64(stmt, 12);
+    s.rating_delta = sqlite3_column_int(stmt, 13);
     out.push_back(std::move(s));
   }
   sqlite3_finalize(stmt);
@@ -395,8 +400,12 @@ std::optional<domain::Submission> SubmissionService::GetById(int64_t id) {
   sqlite3* db = db_.raw();
   sqlite3_stmt* stmt = nullptr;
   const char* sql =
-      "SELECT id,user_id,problem_id,contest_id,language,code,status,score,time_ms,memory_kb,compile_log,runtime_log,created_at "
-      "FROM submissions WHERE id=?";
+      "SELECT s.id,s.user_id,s.problem_id,s.contest_id,s.language,s.code,s.status,s.score,s.time_ms,s.memory_kb,s.compile_log,s.runtime_log,s.created_at,"
+      "CASE WHEN s.status='AC' AND NOT EXISTS ("
+      "  SELECT 1 FROM submissions s2 "
+      "  WHERE s2.user_id=s.user_id AND s2.problem_id=s.problem_id AND s2.status='AC' AND s2.id<s.id"
+      ") THEN 2 ELSE 0 END AS rating_delta "
+      "FROM submissions s WHERE s.id=?";
   CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
               "prepare get submission");
   CheckSqlite(sqlite3_bind_int64(stmt, 1, id), db, "bind submission_id");
@@ -424,6 +433,7 @@ std::optional<domain::Submission> SubmissionService::GetById(int64_t id) {
   s.compile_log = ColText(stmt, 10);
   s.runtime_log = ColText(stmt, 11);
   s.created_at = sqlite3_column_int64(stmt, 12);
+  s.rating_delta = sqlite3_column_int(stmt, 13);
   sqlite3_finalize(stmt);
   return s;
 }

backend/src/services/user_service.cc

@@ -2,8 +2,10 @@
 
 #include <sqlite3.h>
 
+#include <algorithm>
 #include <stdexcept>
 #include <string>
+#include <utility>
 
 namespace csp::services {
 
@@ -70,4 +72,58 @@ std::vector<domain::GlobalLeaderboardEntry> UserService::GlobalLeaderboard(int l
   return out;
 }
 
+UserListResult UserService::ListUsers(int page, int page_size) {
+  const int safe_page = std::max(1, page);
+  const int safe_size = std::max(1, std::min(200, page_size));
+  const int offset = (safe_page - 1) * safe_size;
+
+  sqlite3* db = db_.raw();
+  UserListResult result;
+
+  {
+    sqlite3_stmt* count_stmt = nullptr;
+    const char* count_sql = "SELECT COUNT(1) FROM users";
+    CheckSqlite(sqlite3_prepare_v2(db, count_sql, -1, &count_stmt, nullptr), db,
+                "prepare count users");
+    CheckSqlite(sqlite3_step(count_stmt), db, "step count users");
+    result.total_count = sqlite3_column_int(count_stmt, 0);
+    sqlite3_finalize(count_stmt);
+  }
+
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql =
+      "SELECT id,username,rating,created_at FROM users ORDER BY id ASC LIMIT ? OFFSET ?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare list users");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, safe_size), db, "bind limit");
+  CheckSqlite(sqlite3_bind_int(stmt, 2, offset), db, "bind offset");
+
+  while (sqlite3_step(stmt) == SQLITE_ROW) {
+    domain::GlobalLeaderboardEntry e;
+    e.user_id = sqlite3_column_int64(stmt, 0);
+    e.username = ColText(stmt, 1);
+    e.rating = sqlite3_column_int(stmt, 2);
+    e.created_at = sqlite3_column_int64(stmt, 3);
+    result.items.push_back(std::move(e));
+  }
+  sqlite3_finalize(stmt);
+  return result;
+}
+
+void UserService::SetRating(int64_t user_id, int rating) {
+  if (user_id <= 0) throw std::runtime_error("invalid user_id");
+  if (rating < 0) throw std::runtime_error("rating must be >= 0");
+
+  sqlite3* db = db_.raw();
+  sqlite3_stmt* stmt = nullptr;
+  const char* sql = "UPDATE users SET rating=? WHERE id=?";
+  CheckSqlite(sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr), db,
+              "prepare set user rating");
+  CheckSqlite(sqlite3_bind_int(stmt, 1, rating), db, "bind rating");
+  CheckSqlite(sqlite3_bind_int64(stmt, 2, user_id), db, "bind user_id");
+  CheckSqlite(sqlite3_step(stmt), db, "exec set user rating");
+  sqlite3_finalize(stmt);
+  if (sqlite3_changes(db) <= 0) throw std::runtime_error("user not found");
+}
+
 }  // namespace csp::services

backend/tests/problem_workspace_service_test.cc

@@ -42,7 +42,21 @@ TEST_CASE("problem workspace service drafts and solution jobs") {
   REQUIRE(latest->id == job_id);
   REQUIRE(latest->status == "queued");
   REQUIRE(latest->max_solutions == 3);
+  REQUIRE(latest->problem_title.empty());
+
+  const auto recent = svc.ListRecentSolutionJobs(10);
+  REQUIRE(recent.size() == 1);
+  REQUIRE(recent.front().id == job_id);
+  REQUIRE(recent.front().problem_id == pid);
+  REQUIRE(!recent.front().problem_title.empty());
 
   const auto solutions = svc.ListSolutions(pid);
   REQUIRE(solutions.empty());
+
+  REQUIRE(svc.CountProblemsWithoutSolutions() >= 1);
+  const auto missing_all = svc.ListProblemIdsWithoutSolutions(10, false);
+  REQUIRE(!missing_all.empty());
+  const auto missing_skip_busy = svc.ListProblemIdsWithoutSolutions(10, true);
+  REQUIRE(!missing_skip_busy.empty());
+  REQUIRE(missing_skip_busy.size() < missing_all.size());
 }

docker-compose.yml

@@ -4,16 +4,24 @@ services:
       - .env
     environment:
       - OI_IMPORT_AUTO_RUN=true
+      - OI_IMPORT_AUTO_MODE=luogu
       - OI_IMPORT_WORKERS=3
       - OI_IMPORT_SCRIPT_PATH=/app/scripts/import_luogu_csp.py
-      - OI_IMPORT_CLEAR_ALL_PROBLEMS=true
-      - OI_IMPORT_CLEAR_EXISTING=true
+      - OI_IMPORT_LOCAL_RAG_SCRIPT_PATH=/app/scripts/import_local_pdf_rag.py
+      - OI_LOCAL_PDF_DIR=/data/local_pdfs
+      - OI_IMPORT_TARGET_TOTAL=5000
+      - OI_IMPORT_RESUME_ON_RESTART=true
+      - OI_IMPORT_CLEAR_ALL_PROBLEMS=false
+      - OI_IMPORT_CLEAR_EXISTING=false
       - "OI_IMPORT_CLEAR_SOURCE_PREFIX=luogu:"
       - CSP_GEN_AUTO_RUN=true
       - CSP_GEN_COUNT=1
       - CSP_GEN_WAIT_FOR_IMPORT=true
       - CSP_GEN_SCRIPT_PATH=/app/scripts/generate_cspj_problem_rag.py
       - CSP_SOLUTION_SCRIPT_PATH=/app/scripts/generate_problem_solutions.py
+      - CSP_SOLUTION_AUTO_RUN_MISSING=true
+      - CSP_SOLUTION_AUTO_LIMIT=50000
+      - CSP_SOLUTION_AUTO_MAX_SOLUTIONS=3
     build:
       context: .
       dockerfile: Dockerfile.backend
@@ -22,6 +30,7 @@ services:
     #   - "8080:8080"
     volumes:
       - csp_data:/data
+      - ./data/local_pdfs:/data/local_pdfs
     restart: unless-stopped
 
   frontend:

docs/API参考.md

@@ -140,3 +140,20 @@
 ```json
 { "clear_all_problems": true }
 ```
+
+也支持本地 PDF + RAG + LLM 出题模式（异步执行，进度同样写入 `import_jobs/import_job_items`）：
+```json
+{
+  "mode": "local_pdf_rag",
+  "workers": 3,
+  "local_pdf_dir": "/data/local_pdfs",
+  "target_total": 5000
+}
+```
+
+---
+
+## 9) 后台日志（题解异步队列）
+
+### `GET /backend/logs?limit=100`
+返回最近题解生成任务日志（按任务 ID 倒序），并包含当前排队任务数 `pending_jobs`。

frontend/src/app/admin-redeem/page.tsx

@@ -0,0 +1,348 @@
+"use client";
+
+import { useEffect, useState } from "react";
+
+import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
+
+type RedeemItem = {
+  id: number;
+  name: string;
+  description: string;
+  unit_label: string;
+  holiday_cost: number;
+  studyday_cost: number;
+  is_active: boolean;
+  is_global: boolean;
+  created_at: number;
+  updated_at: number;
+};
+
+type RedeemRecord = {
+  id: number;
+  user_id: number;
+  username: string;
+  item_id: number;
+  item_name: string;
+  quantity: number;
+  day_type: string;
+  unit_cost: number;
+  total_cost: number;
+  note: string;
+  created_at: number;
+};
+
+type ItemForm = {
+  name: string;
+  description: string;
+  unit_label: string;
+  holiday_cost: number;
+  studyday_cost: number;
+  is_active: boolean;
+  is_global: boolean;
+};
+
+const DEFAULT_FORM: ItemForm = {
+  name: "",
+  description: "",
+  unit_label: "hour",
+  holiday_cost: 5,
+  studyday_cost: 25,
+  is_active: true,
+  is_global: true,
+};
+
+function fmtTs(v: number | null | undefined): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
+export default function AdminRedeemPage() {
+  const { tx } = useI18nText();
+  const [token, setToken] = useState("");
+  const [items, setItems] = useState<RedeemItem[]>([]);
+  const [records, setRecords] = useState<RedeemRecord[]>([]);
+  const [form, setForm] = useState<ItemForm>(DEFAULT_FORM);
+  const [editingId, setEditingId] = useState<number | null>(null);
+
+  const [recordUserId, setRecordUserId] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [saving, setSaving] = useState(false);
+  const [error, setError] = useState("");
+  const [msg, setMsg] = useState("");
+
+  const load = async () => {
+    setLoading(true);
+    setError("");
+    try {
+      const tk = readToken();
+      setToken(tk);
+      if (!tk) throw new Error(tx("请先登录管理员账号", "Please sign in with admin account first"));
+
+      const recordsQs = new URLSearchParams({ limit: "200" });
+      if (recordUserId.trim()) recordsQs.set("user_id", recordUserId.trim());
+
+      const [itemRows, recordRows] = await Promise.all([
+        apiFetch<RedeemItem[]>("/api/v1/admin/redeem-items?include_inactive=1", {}, tk),
+        apiFetch<RedeemRecord[]>(`/api/v1/admin/redeem-records?${recordsQs.toString()}`, {}, tk),
+      ]);
+      setItems(itemRows ?? []);
+      setRecords(recordRows ?? []);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  useEffect(() => {
+    void load();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const submit = async () => {
+    setSaving(true);
+    setError("");
+    setMsg("");
+    try {
+      if (!token) throw new Error(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      if (!form.name.trim()) throw new Error(tx("物品名称不能为空", "Item name is required"));
+      const payload = {
+        ...form,
+        name: form.name.trim(),
+        description: form.description.trim(),
+        unit_label: form.unit_label.trim() || tx("小时", "hour"),
+      };
+
+      if (editingId) {
+        await apiFetch(`/api/v1/admin/redeem-items/${editingId}`, {
+          method: "PATCH",
+          body: JSON.stringify(payload),
+        }, token);
+        setMsg(tx(`已更新兑换物品 #${editingId}`, `Updated redeem item #${editingId}`));
+      } else {
+        await apiFetch("/api/v1/admin/redeem-items", {
+          method: "POST",
+          body: JSON.stringify(payload),
+        }, token);
+        setMsg(tx("已新增兑换物品", "Added redeem item"));
+      }
+
+      setForm(DEFAULT_FORM);
+      setEditingId(null);
+      await load();
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setSaving(false);
+    }
+  };
+
+  const edit = (item: RedeemItem) => {
+    setEditingId(item.id);
+    setForm({
+      name: item.name,
+      description: item.description,
+      unit_label: item.unit_label,
+      holiday_cost: item.holiday_cost,
+      studyday_cost: item.studyday_cost,
+      is_active: item.is_active,
+      is_global: item.is_global,
+    });
+  };
+
+  const deactivate = async (id: number) => {
+    setError("");
+    setMsg("");
+    try {
+      if (!token) throw new Error(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      await apiFetch(`/api/v1/admin/redeem-items/${id}`, { method: "DELETE" }, token);
+      setMsg(tx(`已下架兑换物品 #${id}`, `Disabled redeem item #${id}`));
+      await load();
+    } catch (e: unknown) {
+      setError(String(e));
+    }
+  };
+
+  return (
+    <main className="mx-auto max-w-7xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("管理员：积分兑换管理", "Admin: Redeem Management")}
+      </h1>
+      <p className="mt-1 text-sm text-zinc-600">
+        {tx(
+          "可在此添加/修改/下架全局兑换物品，并查看全站兑换记录。",
+          "Add/update/disable global redeem items and view all redeem records here."
+        )}
+      </p>
+
+      {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
+      {msg && <p className="mt-3 text-sm text-emerald-700">{msg}</p>}
+
+      <section className="mt-4 rounded-xl border bg-white p-4">
+        <h2 className="text-base font-semibold">{tx("兑换物品表单（增删改查）", "Redeem Item Form (CRUD)")}</h2>
+        <div className="mt-3 grid gap-2 md:grid-cols-2">
+          <input
+            className="rounded border px-3 py-2 text-sm"
+            placeholder={tx("物品名称", "Item name")}
+            value={form.name}
+            onChange={(e) => setForm((prev) => ({ ...prev, name: e.target.value }))}
+          />
+          <input
+            className="rounded border px-3 py-2 text-sm"
+            placeholder={tx("单位（如：小时）", "Unit (e.g. hour)")}
+            value={form.unit_label}
+            onChange={(e) => setForm((prev) => ({ ...prev, unit_label: e.target.value }))}
+          />
+          <input
+            className="rounded border px-3 py-2 text-sm"
+            type="number"
+            min={0}
+            placeholder={tx("假期单价", "Holiday unit cost")}
+            value={form.holiday_cost}
+            onChange={(e) =>
+              setForm((prev) => ({ ...prev, holiday_cost: Math.max(0, Number(e.target.value) || 0) }))
+            }
+          />
+          <input
+            className="rounded border px-3 py-2 text-sm"
+            type="number"
+            min={0}
+            placeholder={tx("学习日单价", "Study-day unit cost")}
+            value={form.studyday_cost}
+            onChange={(e) =>
+              setForm((prev) => ({ ...prev, studyday_cost: Math.max(0, Number(e.target.value) || 0) }))
+            }
+          />
+          <textarea
+            className="rounded border px-3 py-2 text-sm md:col-span-2"
+            placeholder={tx("描述", "Description")}
+            value={form.description}
+            onChange={(e) => setForm((prev) => ({ ...prev, description: e.target.value }))}
+          />
+          <label className="flex items-center gap-2 text-sm">
+            <input
+              type="checkbox"
+              checked={form.is_active}
+              onChange={(e) => setForm((prev) => ({ ...prev, is_active: e.target.checked }))}
+            />
+            {tx("启用", "Enabled")}
+          </label>
+          <label className="flex items-center gap-2 text-sm">
+            <input
+              type="checkbox"
+              checked={form.is_global}
+              onChange={(e) => setForm((prev) => ({ ...prev, is_global: e.target.checked }))}
+            />
+            {tx("全局可兑换", "Global redeemable")}
+          </label>
+        </div>
+
+        <div className="mt-3 flex flex-wrap gap-2">
+          <button
+            className="rounded bg-zinc-900 px-4 py-2 text-sm text-white disabled:opacity-50"
+            onClick={() => void submit()}
+            disabled={saving}
+          >
+            {saving
+              ? tx("保存中...", "Saving...")
+              : editingId
+                ? tx(`保存修改 #${editingId}`, `Save changes #${editingId}`)
+                : tx("新增物品", "Add item")}
+          </button>
+          <button
+            className="rounded border px-4 py-2 text-sm"
+            onClick={() => {
+              setEditingId(null);
+              setForm(DEFAULT_FORM);
+            }}
+          >
+            {tx("清空表单", "Clear form")}
+          </button>
+          <button
+            className="rounded border px-4 py-2 text-sm"
+            onClick={() => void load()}
+            disabled={loading}
+          >
+            {tx("刷新数据", "Refresh data")}
+          </button>
+        </div>
+      </section>
+
+      <section className="mt-4 rounded-xl border bg-white p-4">
+        <h2 className="text-base font-semibold">{tx("兑换物品列表", "Redeem Items")}</h2>
+        <div className="mt-3 divide-y">
+          {items.map((item) => (
+            <article key={item.id} className="py-2 text-sm">
+              <p>
+                #{item.id} · {item.name} · {tx("假期", "Holiday")} {item.holiday_cost}/{item.unit_label} · {tx("学习日", "Study Day")} {item.studyday_cost}/
+                {item.unit_label}
+              </p>
+              <p className="text-xs text-zinc-600">
+                {tx("状态：", "Status: ")}
+                {item.is_active ? tx("启用", "Enabled") : tx("下架", "Disabled")}
+                {" · "}
+                {tx("范围：", "Scope: ")}
+                {item.is_global ? tx("全局", "Global") : tx("非全局", "Non-global")}
+                {" · "}
+                {tx("更新：", "Updated: ")}
+                {fmtTs(item.updated_at)}
+              </p>
+              <p className="text-xs text-zinc-500">{item.description || "-"}</p>
+              <div className="mt-1 flex gap-2">
+                <button className="rounded border px-2 py-1 text-xs" onClick={() => edit(item)}>
+                  {tx("编辑", "Edit")}
+                </button>
+                <button className="rounded border px-2 py-1 text-xs" onClick={() => void deactivate(item.id)}>
+                  {tx("下架", "Disable")}
+                </button>
+              </div>
+            </article>
+          ))}
+          {!loading && items.length === 0 && (
+            <p className="py-3 text-sm text-zinc-500">{tx("暂无兑换物品。", "No redeem items yet.")}</p>
+          )}
+        </div>
+      </section>
+
+      <section className="mt-4 rounded-xl border bg-white p-4">
+        <div className="flex flex-wrap items-center gap-2">
+          <h2 className="text-base font-semibold">{tx("兑换记录", "Redeem Records")}</h2>
+          <input
+            className="rounded border px-3 py-1 text-xs"
+            placeholder={tx("按 user_id 筛选（可选）", "Filter by user_id (optional)")}
+            value={recordUserId}
+            onChange={(e) => setRecordUserId(e.target.value)}
+          />
+          <button className="rounded border px-3 py-1 text-xs" onClick={() => void load()}>
+            {tx("筛选/刷新", "Filter / Refresh")}
+          </button>
+        </div>
+
+        <div className="mt-3 divide-y">
+          {records.map((row) => (
+            <article key={row.id} className="py-2 text-sm">
+              <p>
+                #{row.id} · {tx("用户", "User")} {row.user_id}({row.username || "-"}) · {row.item_name} × {row.quantity}
+              </p>
+              <p className="text-xs text-zinc-600">
+                {row.day_type === "holiday" ? tx("假期", "Holiday") : tx("学习日", "Study Day")}
+                {" · "}
+                {tx("单价", "Unit cost")} {row.unit_cost}
+                {" · "}
+                {tx("扣分", "Cost")} {row.total_cost}
+                {" · "}
+                {fmtTs(row.created_at)}
+              </p>
+              {row.note && <p className="text-xs text-zinc-500">{tx("备注：", "Note: ")}{row.note}</p>}
+            </article>
+          ))}
+          {!loading && records.length === 0 && (
+            <p className="py-3 text-sm text-zinc-500">{tx("暂无兑换记录。", "No redeem records yet.")}</p>
+          )}
+        </div>
+      </section>
+    </main>
+  );
+}

frontend/src/app/admin-users/page.tsx

@@ -0,0 +1,192 @@
+"use client";
+
+import { useEffect, useState } from "react";
+
+import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
+
+type AdminUser = {
+  id: number;
+  username: string;
+  rating: number;
+  created_at: number;
+};
+
+type ListResp = {
+  items: AdminUser[];
+  total_count: number;
+  page: number;
+  page_size: number;
+};
+
+function fmtTs(v: number): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
+export default function AdminUsersPage() {
+  const { tx } = useI18nText();
+  const [items, setItems] = useState<AdminUser[]>([]);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState("");
+  const [msg, setMsg] = useState("");
+
+  const load = async () => {
+    setLoading(true);
+    setError("");
+    try {
+      const token = readToken();
+      if (!token) throw new Error(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      const data = await apiFetch<ListResp>("/api/v1/admin/users?page=1&page_size=200", undefined, token);
+      setItems(data.items ?? []);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  useEffect(() => {
+    void load();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const updateRating = async (userId: number, rating: number) => {
+    setMsg("");
+    setError("");
+    try {
+      const token = readToken();
+      if (!token) throw new Error(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      await apiFetch(
+        `/api/v1/admin/users/${userId}/rating`,
+        {
+          method: "PATCH",
+          body: JSON.stringify({ rating }),
+        },
+        token
+      );
+      setMsg(tx(`已更新用户 ${userId} Rating=${rating}`, `Updated user ${userId} rating=${rating}`));
+      await load();
+    } catch (e: unknown) {
+      setError(String(e));
+    }
+  };
+
+  return (
+    <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("管理员用户与积分", "Admin Users & Rating")}
+      </h1>
+      <p className="mt-2 text-sm text-zinc-600">
+        {tx("默认管理员账号：", "Default admin account: ")}
+        <code>admin</code> / <code>whoami139</code>
+      </p>
+
+      <div className="mt-4 flex flex-wrap gap-2">
+        <button
+          className="rounded bg-zinc-900 px-4 py-2 text-sm text-white disabled:opacity-50"
+          onClick={() => void load()}
+          disabled={loading}
+        >
+          {loading ? tx("刷新中...", "Refreshing...") : tx("刷新用户列表", "Refresh users")}
+        </button>
+      </div>
+
+      {msg && <p className="mt-3 text-sm text-emerald-700">{msg}</p>}
+      {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
+
+      <div className="mt-4 rounded-xl border bg-white">
+        <div className="hidden overflow-x-auto md:block">
+          <table className="min-w-full text-sm">
+            <thead className="bg-zinc-100 text-left">
+              <tr>
+                <th className="px-3 py-2">ID</th>
+                <th className="px-3 py-2">{tx("用户名", "Username")}</th>
+                <th className="px-3 py-2">Rating</th>
+                <th className="px-3 py-2">{tx("创建时间", "Created At")}</th>
+                <th className="px-3 py-2">{tx("操作", "Action")}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {items.map((user) => (
+                <tr key={user.id} className="border-t">
+                  <td className="px-3 py-2">{user.id}</td>
+                  <td className="px-3 py-2">{user.username}</td>
+                  <td className="px-3 py-2">
+                    <input
+                      className="w-24 rounded border px-2 py-1"
+                      type="number"
+                      min={0}
+                      value={user.rating}
+                      onChange={(e) => {
+                        const value = Number(e.target.value);
+                        setItems((prev) =>
+                          prev.map((row) => (row.id === user.id ? { ...row, rating: value } : row))
+                        );
+                      }}
+                    />
+                  </td>
+                  <td className="px-3 py-2 text-zinc-600">{fmtTs(user.created_at)}</td>
+                  <td className="px-3 py-2">
+                    <button
+                      className="rounded border px-3 py-1 text-xs hover:bg-zinc-100"
+                      onClick={() => void updateRating(user.id, Math.max(0, Number(user.rating) || 0))}
+                    >
+                      {tx("保存", "Save")}
+                    </button>
+                  </td>
+                </tr>
+              ))}
+              {!loading && items.length === 0 && (
+                <tr>
+                  <td className="px-3 py-6 text-center text-zinc-500" colSpan={5}>
+                    {tx("暂无用户数据", "No users found")}
+                  </td>
+                </tr>
+              )}
+            </tbody>
+          </table>
+        </div>
+
+        <div className="divide-y md:hidden">
+          {items.map((user) => (
+            <div key={user.id} className="space-y-2 p-3 text-sm">
+              <p>
+                #{user.id} · {user.username}
+              </p>
+              <p className="text-xs text-zinc-500">
+                {tx("创建时间：", "Created: ")}
+                {fmtTs(user.created_at)}
+              </p>
+              <div className="flex items-center gap-2">
+                <span className="text-xs text-zinc-600">Rating</span>
+                <input
+                  className="w-24 rounded border px-2 py-1 text-xs"
+                  type="number"
+                  min={0}
+                  value={user.rating}
+                  onChange={(e) => {
+                    const value = Number(e.target.value);
+                    setItems((prev) =>
+                      prev.map((row) => (row.id === user.id ? { ...row, rating: value } : row))
+                    );
+                  }}
+                />
+                <button
+                  className="rounded border px-3 py-1 text-xs"
+                  onClick={() => void updateRating(user.id, Math.max(0, Number(user.rating) || 0))}
+                >
+                  {tx("保存", "Save")}
+                </button>
+              </div>
+            </div>
+          ))}
+          {!loading && items.length === 0 && (
+            <p className="px-3 py-6 text-center text-sm text-zinc-500">{tx("暂无用户数据", "No users found")}</p>
+          )}
+        </div>
+      </div>
+    </main>
+  );
+}

frontend/src/app/admin139/page.tsx

@@ -1,28 +1,25 @@
-import Link from "next/link";
+"use client";
+
+import { useRouter } from "next/navigation";
+import { useEffect } from "react";
+
+import { useUiPreferences } from "@/components/ui-preference-provider";
 
 export default function AdminEntryPage() {
+  const { t } = useUiPreferences();
+  const router = useRouter();
+
+  useEffect(() => {
+    router.replace("/imports");
+  }, [router]);
+
   return (
     <main className="mx-auto max-w-3xl px-4 py-10">
-      <h1 className="text-2xl font-semibold">后台管理入口</h1>
-      <p className="mt-3 text-sm text-zinc-600">
-        默认管理员账号：<span className="font-medium text-zinc-900">admin</span>，密码：
-        <span className="font-medium text-zinc-900">whoami139</span>
+      <h1 className="text-2xl font-semibold">{t("admin.entry.title")}</h1>
+      <p className="mt-3 text-sm text-zinc-600">{t("admin.entry.desc")}</p>
+      <p className="mt-2 text-sm text-zinc-500">
+        {t("admin.entry.moved_to_platform")}
       </p>
-
-      <div className="mt-6 grid gap-3 sm:grid-cols-2">
-        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/auth">
-          去登录
-        </Link>
-        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/admin-users">
-          用户积分管理
-        </Link>
-        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/admin-redeem">
-          积分兑换管理
-        </Link>
-        <Link className="rounded-lg border bg-white px-4 py-3 text-sm hover:bg-zinc-50" href="/backend-logs">
-          后台任务日志
-        </Link>
-      </div>
     </main>
   );
 }

frontend/src/app/api-docs/page.tsx

@@ -1,19 +1,80 @@
 "use client";
 
 import dynamic from "next/dynamic";
-import { useMemo } from "react";
+import { useEffect, useMemo, useState } from "react";
 
-import { API_BASE } from "@/lib/api";
+import { API_BASE, apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 const SwaggerUI = dynamic(() => import("swagger-ui-react"), { ssr: false });
 
 export default function ApiDocsPage() {
+  const { tx } = useI18nText();
   const specUrl = useMemo(() => `${API_BASE}/api/openapi.json`, []);
+  const [checkingAdmin, setCheckingAdmin] = useState(true);
+  const [isAdmin, setIsAdmin] = useState(false);
+  const [error, setError] = useState("");
+
+  useEffect(() => {
+    let canceled = false;
+    const checkAdmin = async () => {
+      const token = readToken();
+      if (!token) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(tx("请先登录管理员账号", "Please sign in with admin account first"));
+          setCheckingAdmin(false);
+        }
+        return;
+      }
+      try {
+        const me = await apiFetch<{ username?: string }>("/api/v1/me", {}, token);
+        if (!canceled) {
+          const allowed = (me?.username ?? "") === "admin";
+          setIsAdmin(allowed);
+          setError(allowed ? "" : tx("仅管理员可查看 API 文档", "API docs are visible to admin only"));
+        }
+      } catch (e: unknown) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(String(e));
+        }
+      } finally {
+        if (!canceled) setCheckingAdmin(false);
+      }
+    };
+    void checkAdmin();
+    return () => {
+      canceled = true;
+    };
+  }, [tx]);
+
+  if (checkingAdmin) {
+    return (
+      <main className="mx-auto max-w-7xl px-3 py-8 text-sm text-zinc-600">
+        {tx("正在校验管理员权限...", "Checking admin access...")}
+      </main>
+    );
+  }
+
+  if (!isAdmin) {
+    return (
+      <main className="mx-auto max-w-7xl px-3 py-8">
+        <h1 className="text-xl font-semibold">{tx("API 文档（Swagger）", "API Docs (Swagger)")}</h1>
+        <p className="mt-3 text-sm text-red-600">
+          {error || tx("仅管理员可查看此页面", "This page is available for admin only")}
+        </p>
+      </main>
+    );
+  }
 
   return (
-    <main className="mx-auto max-w-7xl px-6 py-6">
-      <h1 className="mb-4 text-2xl font-semibold">API 文档（Swagger）</h1>
-      <div className="rounded-xl border bg-white p-2">
+    <main className="mx-auto max-w-7xl px-3 py-5 max-[390px]:px-2 sm:px-4 md:px-6 md:py-6">
+      <h1 className="mb-4 text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("API 文档（Swagger）", "API Docs (Swagger)")}
+      </h1>
+      <div className="overflow-x-auto rounded-xl border bg-white p-2">
         <SwaggerUI url={specUrl} docExpansion="list" defaultModelsExpandDepth={1} />
       </div>
     </main>

frontend/src/app/auth/page.tsx

@@ -1,25 +1,28 @@
 "use client";
 
 import Link from "next/link";
-import { useMemo, useState } from "react";
+import { useEffect, useMemo, useState } from "react";
 import { useRouter } from "next/navigation";
 
 import { API_BASE, apiFetch } from "@/lib/api";
-import { saveToken } from "@/lib/auth";
+import { readToken, saveToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type AuthOk = { ok: true; user_id: number; token: string; expires_at: number };
 type AuthErr = { ok: false; error: string };
 type AuthResp = AuthOk | AuthErr;
 
-function passwordScore(password: string): { label: string; color: string } {
-  if (password.length >= 12) return { label: "强", color: "text-emerald-600" };
-  if (password.length >= 8) return { label: "中", color: "text-blue-600" };
-  return { label: "弱", color: "text-orange-600" };
+function passwordScore(password: string, isZh: boolean): { label: string; color: string } {
+  if (password.length >= 12) return { label: isZh ? "强" : "Strong", color: "text-emerald-600" };
+  if (password.length >= 8) return { label: isZh ? "中" : "Medium", color: "text-blue-600" };
+  return { label: isZh ? "弱" : "Weak", color: "text-orange-600" };
 }
 
 export default function AuthPage() {
+  const { isZh, tx } = useI18nText();
   const router = useRouter();
   const apiBase = useMemo(() => API_BASE, []);
+  const [checkingAuth, setCheckingAuth] = useState(true);
 
   const [mode, setMode] = useState<"register" | "login">("login");
   const [username, setUsername] = useState(process.env.NEXT_PUBLIC_TEST_USERNAME ?? "");
@@ -29,10 +32,18 @@ export default function AuthPage() {
   const [loading, setLoading] = useState(false);
   const [resp, setResp] = useState<AuthResp | null>(null);
 
-  const usernameErr = username.trim().length < 3 ? "用户名至少 3 位" : "";
-  const passwordErr = password.length < 6 ? "密码至少 6 位" : "";
+  useEffect(() => {
+    if (readToken()) {
+      router.replace("/problems");
+      return;
+    }
+    setCheckingAuth(false);
+  }, [router]);
+
+  const usernameErr = username.trim().length < 3 ? tx("用户名至少 3 位", "Username must be at least 3 chars") : "";
+  const passwordErr = password.length < 6 ? tx("密码至少 6 位", "Password must be at least 6 chars") : "";
   const confirmErr =
-    mode === "register" && password !== confirmPassword ? "两次密码不一致" : "";
+    mode === "register" && password !== confirmPassword ? tx("两次密码不一致", "Passwords do not match") : "";
 
   const canSubmit = !loading && !usernameErr && !passwordErr && !confirmErr;
 
@@ -49,7 +60,7 @@ export default function AuthPage() {
       if (j.ok) {
         saveToken(j.token);
         setTimeout(() => {
-          router.push("/problems");
+          router.replace("/problems");
         }, 350);
       }
     } catch (e: unknown) {
@@ -59,20 +70,28 @@ export default function AuthPage() {
     }
   }
 
-  const strength = passwordScore(password);
+  const strength = passwordScore(password, isZh);
+
+  if (checkingAuth) {
+    return (
+      <main className="mx-auto max-w-4xl px-3 py-12 text-sm text-zinc-500">
+        {tx("已登录，正在跳转...", "Already signed in, redirecting...")}
+      </main>
+    );
+  }
 
   return (
-    <main className="mx-auto max-w-4xl px-6 py-10">
+    <main className="mx-auto max-w-4xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-10">
       <div className="grid gap-6 md:grid-cols-[1.1fr,1fr]">
         <section className="rounded-2xl border bg-zinc-900 p-6 text-zinc-100">
-          <h1 className="text-2xl font-semibold">欢迎回来，开始刷题</h1>
+          <h1 className="text-2xl font-semibold">{tx("欢迎回来，开始刷题", "Welcome back, let's practice")}</h1>
           <p className="mt-3 text-sm text-zinc-300">
-            登录后可提交评测、保存草稿、查看错题本和个人进度。
+            {tx("登录后可提交评测、保存草稿、查看错题本和个人进度。", "After sign-in you can submit, save drafts, review wrong-book, and track your progress.")}
           </p>
           <div className="mt-6 space-y-2 text-sm text-zinc-300">
-            <p>• 题库按 CSP-J / CSP-S / NOIP 入门组织</p>
-            <p>• 题目页支持本地草稿与试运行</p>
-            <p>• 生成式题解会异步入库，支持多解法</p>
+            <p>{tx("• 题库按 CSP-J / CSP-S / NOIP 入门组织", "• Problem sets are organized by CSP-J / CSP-S / NOIP junior")}</p>
+            <p>{tx("• 题目页支持本地草稿与试运行", "• Problem page supports local draft and run")}</p>
+            <p>{tx("• 生成式题解会异步入库，支持多解法", "• Generated solutions are queued asynchronously with multiple methods")}</p>
           </div>
           <p className="mt-6 text-xs text-zinc-400">
             API Base: <span className="font-mono">{apiBase}</span>
@@ -92,7 +111,7 @@ export default function AuthPage() {
               }}
               disabled={loading}
             >
-              登录
+              {tx("登录", "Sign In")}
             </button>
             <button
               type="button"
@@ -105,46 +124,46 @@ export default function AuthPage() {
               }}
               disabled={loading}
             >
-              注册
+              {tx("注册", "Register")}
             </button>
           </div>
 
           <div className="mt-5 space-y-4">
             <div>
-              <label className="text-sm font-medium">用户名</label>
+              <label className="text-sm font-medium">{tx("用户名", "Username")}</label>
               <input
                 className="mt-1 w-full rounded-lg border px-3 py-2"
                 value={username}
                 onChange={(e) => setUsername(e.target.value)}
-                placeholder="例如：csp_student"
+                placeholder={tx("例如：csp_student", "e.g. csp_student")}
               />
               {usernameErr && <p className="mt-1 text-xs text-red-600">{usernameErr}</p>}
             </div>
 
             <div>
               <div className="flex items-center justify-between">
-                <label className="text-sm font-medium">密码</label>
-                <span className={`text-xs ${strength.color}`}>强度：{strength.label}</span>
+                <label className="text-sm font-medium">{tx("密码", "Password")}</label>
+                <span className={`text-xs ${strength.color}`}>{tx("强度", "Strength")}: {strength.label}</span>
               </div>
               <input
                 type={showPassword ? "text" : "password"}
                 className="mt-1 w-full rounded-lg border px-3 py-2"
                 value={password}
                 onChange={(e) => setPassword(e.target.value)}
-                placeholder="至少 6 位"
+                placeholder={tx("至少 6 位", "At least 6 chars")}
               />
               {passwordErr && <p className="mt-1 text-xs text-red-600">{passwordErr}</p>}
             </div>
 
             {mode === "register" && (
               <div>
-                <label className="text-sm font-medium">确认密码</label>
+                <label className="text-sm font-medium">{tx("确认密码", "Confirm Password")}</label>
                 <input
                   type={showPassword ? "text" : "password"}
                   className="mt-1 w-full rounded-lg border px-3 py-2"
                   value={confirmPassword}
                   onChange={(e) => setConfirmPassword(e.target.value)}
-                  placeholder="再输入一次密码"
+                  placeholder={tx("再输入一次密码", "Enter password again")}
                 />
                 {confirmErr && <p className="mt-1 text-xs text-red-600">{confirmErr}</p>}
               </div>
@@ -156,7 +175,7 @@ export default function AuthPage() {
                 checked={showPassword}
                 onChange={(e) => setShowPassword(e.target.checked)}
               />
-              显示密码
+              {tx("显示密码", "Show password")}
             </label>
 
             <button
@@ -164,7 +183,7 @@ export default function AuthPage() {
               onClick={() => void submit()}
               disabled={!canSubmit}
             >
-              {loading ? "提交中..." : mode === "register" ? "注册并登录" : "登录"}
+              {loading ? tx("提交中...", "Submitting...") : mode === "register" ? tx("注册并登录", "Register & Sign In") : tx("登录", "Sign In")}
             </button>
           </div>
 
@@ -175,21 +194,21 @@ export default function AuthPage() {
               }`}
             >
               {resp.ok
-                ? "登录成功，正在跳转到题库..."
-                : `操作失败：${resp.error}`}
+                ? tx("登录成功，正在跳转到题库...", "Signed in. Redirecting to problem set...")
+                : `${tx("操作失败：", "Action failed: ")}${resp.error}`}
             </div>
           )}
 
           <p className="mt-4 text-xs text-zinc-500">
-            登录后 Token 自动保存在浏览器 localStorage，可直接前往
+            {tx("登录后 Token 自动保存在浏览器 localStorage，可直接前往", "Token is stored in browser localStorage after sign-in. You can go to")}
             <Link className="mx-1 underline" href="/problems">
-              题库
+              {tx("题库", "Problems")}
             </Link>
-            与
+            {tx("与", "and")}
             <Link className="mx-1 underline" href="/me">
-              我的
+              {tx("我的", "My Account")}
             </Link>
-            页面。
+            {tx("页面。", ".")}
           </p>
         </section>
       </div>

frontend/src/app/backend-logs/page.tsx

@@ -0,0 +1,383 @@
+"use client";
+
+import Link from "next/link";
+import { useEffect, useState } from "react";
+
+import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
+
+type BackendLogItem = {
+  id: number;
+  problem_id: number;
+  problem_title: string;
+  status: string;
+  progress: number;
+  message: string;
+  created_by: number;
+  max_solutions: number;
+  created_at: number;
+  started_at: number | null;
+  finished_at: number | null;
+  updated_at: number;
+  runner_pending: boolean;
+};
+
+type QueueJobItem = {
+  id: number;
+  problem_id: number;
+  problem_title: string;
+  status: string;
+  progress: number;
+  message: string;
+  updated_at: number;
+  started_at?: number | null;
+};
+
+type BackendLogsResp = {
+  items: BackendLogItem[];
+  running_jobs: QueueJobItem[];
+  queued_jobs: QueueJobItem[];
+  running_problem_ids: number[];
+  queued_problem_ids: number[];
+  running_count: number;
+  queued_count_preview: number;
+  pending_jobs: number;
+  missing_problems: number;
+  limit: number;
+  running_limit: number;
+  queued_limit: number;
+};
+
+type TriggerMissingResp = {
+  started: boolean;
+  missing_total: number;
+  candidate_count: number;
+  queued_count: number;
+  pending_jobs: number;
+  limit: number;
+  max_solutions: number;
+};
+
+function fmtTs(v: number | null | undefined): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
+export default function BackendLogsPage() {
+  const { tx } = useI18nText();
+  const [token, setToken] = useState("");
+  const [checkingAdmin, setCheckingAdmin] = useState(true);
+  const [isAdmin, setIsAdmin] = useState(false);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState("");
+  const [limit, setLimit] = useState(100);
+  const [pendingJobs, setPendingJobs] = useState(0);
+  const [missingProblems, setMissingProblems] = useState(0);
+  const [items, setItems] = useState<BackendLogItem[]>([]);
+  const [runningJobs, setRunningJobs] = useState<QueueJobItem[]>([]);
+  const [queuedJobs, setQueuedJobs] = useState<QueueJobItem[]>([]);
+  const [runningIds, setRunningIds] = useState<number[]>([]);
+  const [queuedIds, setQueuedIds] = useState<number[]>([]);
+  const [triggerLoading, setTriggerLoading] = useState(false);
+  const [triggerMsg, setTriggerMsg] = useState("");
+
+  const refresh = async () => {
+    if (!isAdmin || !token) return;
+    setLoading(true);
+    setError("");
+    try {
+      const data = await apiFetch<BackendLogsResp>(
+        `/api/v1/backend/logs?limit=${limit}&running_limit=20&queued_limit=100`,
+        {},
+        token
+      );
+      setPendingJobs(data.pending_jobs ?? 0);
+      setMissingProblems(data.missing_problems ?? 0);
+      setItems(data.items ?? []);
+      setRunningJobs(data.running_jobs ?? []);
+      setQueuedJobs(data.queued_jobs ?? []);
+      setRunningIds(data.running_problem_ids ?? []);
+      setQueuedIds(data.queued_problem_ids ?? []);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  useEffect(() => {
+    let canceled = false;
+    const checkAdmin = async () => {
+      setCheckingAdmin(true);
+      const tk = readToken();
+      if (!canceled) setToken(tk);
+      if (!tk) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(tx("请先登录管理员账号", "Please sign in with admin account first"));
+          setCheckingAdmin(false);
+        }
+        return;
+      }
+      try {
+        const me = await apiFetch<{ username?: string }>("/api/v1/me", {}, tk);
+        const allowed = (me?.username ?? "") === "admin";
+        if (!canceled) {
+          setIsAdmin(allowed);
+          if (!allowed) {
+            setError(tx("仅管理员可查看后台日志", "Backend logs are visible to admin only"));
+          } else {
+            setError("");
+          }
+        }
+      } catch (e: unknown) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(String(e));
+        }
+      } finally {
+        if (!canceled) setCheckingAdmin(false);
+      }
+    };
+    void checkAdmin();
+    return () => {
+      canceled = true;
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  useEffect(() => {
+    if (!isAdmin || !token) return;
+    void refresh();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [isAdmin, token, limit]);
+
+  const triggerMissingSolutions = async () => {
+    if (!isAdmin || !token) {
+      setError(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      return;
+    }
+    setTriggerLoading(true);
+    setTriggerMsg("");
+    setError("");
+    try {
+      const data = await apiFetch<TriggerMissingResp>(
+        "/api/v1/backend/solutions/generate-missing",
+        {
+          method: "POST",
+          body: JSON.stringify({ limit: 50000, max_solutions: 3 }),
+        },
+        token
+      );
+      setPendingJobs(data.pending_jobs ?? 0);
+      setTriggerMsg(
+        tx(
+          `已触发异步任务：候选 ${data.candidate_count} 题，入队 ${data.queued_count} 题（当前待处理 ${data.pending_jobs}）。`,
+          `Async trigger submitted: candidate ${data.candidate_count}, queued ${data.queued_count} (pending ${data.pending_jobs}).`
+        )
+      );
+      await refresh();
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setTriggerLoading(false);
+    }
+  };
+
+  useEffect(() => {
+    if (!isAdmin || !token) return;
+    const timer = setInterval(() => {
+      void refresh();
+    }, 5000);
+    return () => clearInterval(timer);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [isAdmin, token, limit]);
+
+  if (checkingAdmin) {
+    return (
+      <main className="mx-auto max-w-7xl px-3 py-8 text-sm text-zinc-600">
+        {tx("正在校验管理员权限...", "Checking admin access...")}
+      </main>
+    );
+  }
+
+  if (!isAdmin) {
+    return (
+      <main className="mx-auto max-w-5xl px-3 py-8">
+        <h1 className="text-xl font-semibold">{tx("后台日志（题解异步队列）", "Backend Logs (Async Solution Queue)")}</h1>
+        <p className="mt-3 text-sm text-red-600">
+          {error || tx("仅管理员可查看此页面", "This page is available for admin only")}
+        </p>
+      </main>
+    );
+  }
+
+  return (
+    <main className="mx-auto max-w-7xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <div className="flex flex-wrap items-center justify-between gap-3">
+        <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+          {tx("后台日志（题解异步队列）", "Backend Logs (Async Solution Queue)")}
+        </h1>
+        <div className="flex w-full flex-wrap items-center gap-2 text-sm sm:w-auto sm:justify-end">
+          <span className={pendingJobs > 0 ? "text-emerald-700" : "text-zinc-600"}>
+            {tx("待处理任务", "Pending jobs")} {pendingJobs}
+          </span>
+          <span className={missingProblems > 0 ? "text-amber-700" : "text-zinc-600"}>
+            {tx("缺失答案题目", "Problems missing answers")} {missingProblems}
+          </span>
+          <button
+            className="rounded border px-3 py-1 disabled:opacity-50"
+            onClick={() => void triggerMissingSolutions()}
+            disabled={triggerLoading}
+          >
+            {triggerLoading ? tx("手动补全中...", "Triggering...") : tx("手动补全（可选）", "Manual fill (optional)")}
+          </button>
+          <select
+            className="rounded border px-2 py-1"
+            value={limit}
+            onChange={(e) => setLimit(Number(e.target.value))}
+          >
+            <option value={50}>{tx("最近 50 条", "Latest 50")}</option>
+            <option value={100}>{tx("最近 100 条", "Latest 100")}</option>
+            <option value={200}>{tx("最近 200 条", "Latest 200")}</option>
+          </select>
+          <button className="rounded border px-3 py-1 sm:ml-auto" onClick={() => void refresh()} disabled={loading}>
+            {tx("刷新", "Refresh")}
+          </button>
+        </div>
+      </div>
+
+      {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
+      {triggerMsg && <p className="mt-3 text-sm text-emerald-700">{triggerMsg}</p>}
+      <p className="mt-3 text-xs text-zinc-500">
+        {tx(
+          "系统已自动单线程异步处理待队列任务，无需手工点击；上方按钮仅用于立即手动补全。",
+          "System auto-processes queued jobs in single-thread async mode; the button above is only for manual trigger."
+        )}
+      </p>
+      <section className="mt-4 grid gap-3 md:grid-cols-2">
+        <article className="rounded-xl border bg-white p-3">
+          <h2 className="text-sm font-medium">{tx("正在处理（Running）", "Running Jobs")}</h2>
+          <p className="mt-1 text-xs text-zinc-600">
+            {tx("当前题目 ID：", "Current problem IDs:")}
+            {runningIds.length ? runningIds.join(", ") : tx("无", "None")}
+          </p>
+          <ul className="mt-2 space-y-2 text-xs">
+            {runningJobs.map((job) => (
+              <li key={job.id} className="rounded border border-zinc-200 p-2">
+                <p>
+                  {tx("任务", "Job")} #{job.id} · {tx("题目", "Problem")} #{job.problem_id} {job.problem_title || tx("(未命名题目)", "(Untitled)")}
+                </p>
+                <p className="text-zinc-600">
+                  {tx("状态", "Status")} {job.status} · {tx("进度", "Progress")} {job.progress}% · {tx("开始", "Start")} {fmtTs(job.started_at ?? null)}
+                </p>
+                <p className="whitespace-pre-wrap break-words text-zinc-600">{job.message || "-"}</p>
+              </li>
+            ))}
+            {!runningJobs.length && <li className="text-zinc-500">{tx("当前无运行中的任务", "No running jobs")}</li>}
+          </ul>
+        </article>
+
+        <article className="rounded-xl border bg-white p-3">
+          <h2 className="text-sm font-medium">{tx("待处理队列（Queued）", "Queued Jobs")}</h2>
+          <p className="mt-1 text-xs text-zinc-600">
+            {tx("待处理题目 ID（预览）：", "Queued problem IDs (preview):")}
+            {queuedIds.length ? queuedIds.join(", ") : tx("无", "None")}
+          </p>
+          <ul className="mt-2 max-h-56 space-y-2 overflow-auto text-xs">
+            {queuedJobs.map((job) => (
+              <li key={job.id} className="rounded border border-zinc-200 p-2">
+                <p>
+                  {tx("任务", "Job")} #{job.id} · {tx("题目", "Problem")} #{job.problem_id} {job.problem_title || tx("(未命名题目)", "(Untitled)")}
+                </p>
+                <p className="text-zinc-600">
+                  {tx("状态", "Status")} {job.status} · {tx("进度", "Progress")} {job.progress}% · {tx("更新", "Updated")} {fmtTs(job.updated_at)}
+                </p>
+                <p className="whitespace-pre-wrap break-words text-zinc-600">{job.message || "-"}</p>
+              </li>
+            ))}
+            {!queuedJobs.length && <li className="text-zinc-500">{tx("当前无待处理任务", "No queued jobs")}</li>}
+          </ul>
+        </article>
+      </section>
+
+      <section className="mt-4 rounded-xl border bg-white">
+        <div className="divide-y md:hidden">
+          {items.map((item) => (
+            <article key={item.id} className="space-y-2 p-3 text-xs">
+              <div className="flex items-center justify-between gap-2">
+                <p className="font-medium">
+                  {tx("任务", "Job")} #{item.id}
+                </p>
+                <span className={item.runner_pending ? "text-emerald-700" : "text-zinc-700"}>
+                  {item.status} · {item.progress}%
+                </span>
+              </div>
+              <Link className="text-blue-600 hover:underline" href={`/problems/${item.problem_id}`}>
+                #{item.problem_id} {item.problem_title || tx("(未命名题目)", "(Untitled)")}
+              </Link>
+              <p className="whitespace-pre-wrap break-words text-zinc-600">{item.message || "-"}</p>
+              <p className="text-zinc-500">
+                {tx("创建", "Created")} {fmtTs(item.created_at)} · {tx("开始", "Start")} {fmtTs(item.started_at)} · {tx("结束", "End")} {fmtTs(item.finished_at)}
+              </p>
+            </article>
+          ))}
+          {!loading && items.length === 0 && (
+            <p className="px-3 py-6 text-center text-sm text-zinc-500">{tx("暂无后台任务日志", "No backend logs yet")}</p>
+          )}
+        </div>
+
+        <div className="hidden overflow-x-auto md:block">
+          <table className="min-w-full text-xs">
+            <thead className="bg-zinc-100 text-left">
+              <tr>
+                <th className="px-2 py-2">{tx("任务ID", "Job ID")}</th>
+                <th className="px-2 py-2">{tx("题目", "Problem")}</th>
+                <th className="px-2 py-2">{tx("状态", "Status")}</th>
+                <th className="px-2 py-2">{tx("进度", "Progress")}</th>
+                <th className="px-2 py-2">{tx("消息", "Message")}</th>
+                <th className="px-2 py-2">{tx("时间", "Time")}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {items.map((item) => (
+                <tr key={item.id} className="border-t align-top">
+                  <td className="px-2 py-2 font-medium">{item.id}</td>
+                  <td className="max-w-[260px] px-2 py-2">
+                    <Link className="text-blue-600 hover:underline" href={`/problems/${item.problem_id}`}>
+                      #{item.problem_id} {item.problem_title || tx("(未命名题目)", "(Untitled)")}
+                    </Link>
+                  </td>
+                  <td className="px-2 py-2">
+                    <span className={item.runner_pending ? "text-emerald-700" : "text-zinc-700"}>
+                      {item.status}
+                    </span>
+                  </td>
+                  <td className="px-2 py-2">{item.progress}%</td>
+                  <td className="max-w-[420px] px-2 py-2">
+                    <div className="whitespace-pre-wrap break-words">{item.message || "-"}</div>
+                  </td>
+                  <td className="px-2 py-2 text-zinc-600">
+                    {tx("创建", "Created")} {fmtTs(item.created_at)}
+                    <br />
+                    {tx("开始", "Start")} {fmtTs(item.started_at)}
+                    <br />
+                    {tx("结束", "End")} {fmtTs(item.finished_at)}
+                  </td>
+                </tr>
+              ))}
+              {!loading && items.length === 0 && (
+                <tr>
+                  <td className="px-2 py-6 text-center text-zinc-500" colSpan={6}>
+                    {tx("暂无后台任务日志", "No backend logs yet")}
+                  </td>
+                </tr>
+              )}
+            </tbody>
+          </table>
+        </div>
+      </section>
+    </main>
+  );
+}

frontend/src/app/contests/[id]/page.tsx

@@ -6,6 +6,7 @@ import { useEffect, useMemo, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
 import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type Contest = {
   id: number;
@@ -35,6 +36,7 @@ type DetailResp = {
 };
 
 export default function ContestDetailPage() {
+  const { tx } = useI18nText();
   const params = useParams<{ id: string }>();
   const contestId = useMemo(() => Number(params.id), [params.id]);
 
@@ -69,7 +71,7 @@ export default function ContestDetailPage() {
   const register = async () => {
     try {
       const token = readToken();
-      if (!token) throw new Error("请先登录");
+      if (!token) throw new Error(tx("请先登录", "Please sign in first"));
       await apiFetch(`/api/v1/contests/${contestId}/register`, { method: "POST" }, token);
       await load();
     } catch (e: unknown) {
@@ -78,9 +80,11 @@ export default function ContestDetailPage() {
   };
 
   return (
-    <main className="mx-auto max-w-6xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">比赛详情 #{contestId}</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
+    <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("比赛详情", "Contest Detail")} #{contestId}
+      </h1>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
       {detail && (
@@ -91,24 +95,29 @@ export default function ContestDetailPage() {
               {new Date(detail.contest.starts_at * 1000).toLocaleString()} - {" "}
               {new Date(detail.contest.ends_at * 1000).toLocaleString()}
             </p>
-            <pre className="mt-3 rounded bg-zinc-900 p-3 text-xs text-zinc-100">
+            <pre className="mt-3 overflow-x-auto rounded bg-zinc-900 p-3 text-xs text-zinc-100">
               {detail.contest.rule_json}
             </pre>
 
             <button
-              className="mt-3 rounded bg-zinc-900 px-4 py-2 text-white"
+              className="mt-3 w-full rounded bg-zinc-900 px-4 py-2 text-white sm:w-auto"
               onClick={() => void register()}
             >
-              {detail.registered ? "已报名（可重复点击刷新）" : "报名比赛"}
+              {detail.registered
+                ? tx("已报名（可重复点击刷新）", "Registered (click again to refresh)")
+                : tx("报名比赛", "Register Contest")}
             </button>
 
-            <h3 className="mt-4 text-sm font-medium">比赛题目</h3>
+            <h3 className="mt-4 text-sm font-medium">{tx("比赛题目", "Contest Problems")}</h3>
             <ul className="mt-2 space-y-2 text-sm">
               {detail.problems.map((p) => (
                 <li key={p.id} className="rounded border p-2">
-                  #{p.id} {p.title}（难度 {p.difficulty}）
-                  <Link className="ml-2 text-blue-600 underline" href={`/problems/${p.id}`}>
-                    去提交
+                  #{p.id} {p.title}
+                  {tx("（难度 ", " (Difficulty ")}
+                  {p.difficulty}
+                  {tx("）", ")")}
+                  <Link className="mt-1 block text-blue-600 underline sm:ml-2 sm:mt-0 sm:inline" href={`/problems/${p.id}`}>
+                    {tx("去提交", "Submit")}
                   </Link>
                 </li>
               ))}
@@ -116,28 +125,55 @@ export default function ContestDetailPage() {
           </section>
 
           <section className="rounded-xl border bg-white p-4">
-            <h3 className="text-sm font-medium">排行榜</h3>
-            <div className="mt-2 overflow-x-auto">
-              <table className="min-w-full text-sm">
-                <thead className="bg-zinc-100 text-left">
-                  <tr>
-                    <th className="px-2 py-1">#</th>
-                    <th className="px-2 py-1">用户</th>
-                    <th className="px-2 py-1">Solved</th>
-                    <th className="px-2 py-1">Penalty(s)</th>
-                  </tr>
-                </thead>
-                <tbody>
-                  {board.map((r, idx) => (
-                    <tr key={r.user_id} className="border-t">
-                      <td className="px-2 py-1">{idx + 1}</td>
-                      <td className="px-2 py-1">{r.username}</td>
-                      <td className="px-2 py-1">{r.solved}</td>
-                      <td className="px-2 py-1">{r.penalty_sec}</td>
+            <h3 className="text-sm font-medium">{tx("排行榜", "Leaderboard")}</h3>
+            <div className="mt-2 rounded-lg border">
+              <div className="divide-y md:hidden">
+                {board.map((r, idx) => (
+                  <article key={r.user_id} className="space-y-1 p-3 text-sm">
+                    <p className="font-medium">
+                      #{idx + 1} · {r.username}
+                    </p>
+                    <p className="text-xs text-zinc-600">
+                      Solved {r.solved} · Penalty {r.penalty_sec}s
+                    </p>
+                  </article>
+                ))}
+                {!loading && board.length === 0 && (
+                  <p className="px-3 py-5 text-center text-sm text-zinc-500">
+                    {tx("暂无榜单数据", "No leaderboard data yet")}
+                  </p>
+                )}
+              </div>
+
+              <div className="hidden overflow-x-auto md:block">
+                <table className="min-w-full text-sm">
+                  <thead className="bg-zinc-100 text-left">
+                    <tr>
+                      <th className="px-2 py-1">#</th>
+                      <th className="px-2 py-1">{tx("用户", "User")}</th>
+                      <th className="px-2 py-1">Solved</th>
+                      <th className="px-2 py-1">Penalty(s)</th>
                     </tr>
-                  ))}
-                </tbody>
-              </table>
+                  </thead>
+                  <tbody>
+                    {board.map((r, idx) => (
+                      <tr key={r.user_id} className="border-t">
+                        <td className="px-2 py-1">{idx + 1}</td>
+                        <td className="px-2 py-1">{r.username}</td>
+                        <td className="px-2 py-1">{r.solved}</td>
+                        <td className="px-2 py-1">{r.penalty_sec}</td>
+                      </tr>
+                    ))}
+                    {!loading && board.length === 0 && (
+                      <tr>
+                        <td className="px-2 py-5 text-center text-zinc-500" colSpan={4}>
+                          {tx("暂无榜单数据", "No leaderboard data yet")}
+                        </td>
+                      </tr>
+                    )}
+                  </tbody>
+                </table>
+              </div>
             </div>
           </section>
         </div>

frontend/src/app/contests/page.tsx

@@ -4,6 +4,7 @@ import Link from "next/link";
 import { useEffect, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type Contest = {
   id: number;
@@ -14,6 +15,7 @@ type Contest = {
 };
 
 export default function ContestsPage() {
+  const { tx } = useI18nText();
   const [items, setItems] = useState<Contest[]>([]);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState("");
@@ -35,9 +37,11 @@ export default function ContestsPage() {
   }, []);
 
   return (
-    <main className="mx-auto max-w-5xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">模拟竞赛</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
+    <main className="mx-auto max-w-5xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("模拟竞赛", "Contests")}
+      </h1>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
       <div className="mt-4 space-y-3">
@@ -48,8 +52,8 @@ export default function ContestsPage() {
             className="block rounded-xl border bg-white p-4 hover:border-zinc-400"
           >
             <h2 className="text-lg font-medium">{c.title}</h2>
-            <p className="mt-1 text-xs text-zinc-500">开始: {new Date(c.starts_at * 1000).toLocaleString()}</p>
-            <p className="text-xs text-zinc-500">结束: {new Date(c.ends_at * 1000).toLocaleString()}</p>
+            <p className="mt-1 text-xs text-zinc-500">{tx("开始", "Start")}: {new Date(c.starts_at * 1000).toLocaleString()}</p>
+            <p className="text-xs text-zinc-500">{tx("结束", "End")}: {new Date(c.ends_at * 1000).toLocaleString()}</p>
           </Link>
         ))}
       </div>

frontend/src/app/globals.css

@@ -1,8 +1,12 @@
 @import "tailwindcss";
 
 :root {
-  --background: #ffffff;
+  --background: #fff;
   --foreground: #171717;
+  --surface: #fff;
+  --surface-soft: #f4f4f5;
+  --border: #d4d4d8;
+  -webkit-text-size-adjust: 100%;
 }
 
 @theme inline {
@@ -13,15 +17,55 @@
     "Courier New", monospace;
 }
 
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
-}
-
 body {
   background: var(--background);
   color: var(--foreground);
   font-family: Arial, Helvetica, sans-serif;
+  min-height: 100vh;
+  overflow-x: hidden;
+}
+
+.problem-markdown-compact {
+  font-size: 70%;
+  line-height: 1.55;
+}
+
+.problem-markdown-compact pre,
+.problem-markdown-compact code {
+  font-size: 1em;
+}
+
+.print-only {
+  display: none;
+}
+
+@media print {
+  body {
+    background: #fff !important;
+    color: #000 !important;
+  }
+
+  .print-hidden {
+    display: none !important;
+  }
+
+  .print-only {
+    display: block !important;
+  }
+
+  .problem-detail-grid {
+    display: block !important;
+  }
+
+  .problem-print-section {
+    border: 0 !important;
+    background: transparent !important;
+    padding: 0 !important;
+  }
+
+  .problem-print-section pre {
+    border: 1px solid #d4d4d8 !important;
+    background: #f4f4f5 !important;
+    color: #111827 !important;
+  }
 }

frontend/src/app/imports/page.tsx

@@ -1,8 +1,11 @@
 "use client";
 
+import Link from "next/link";
 import { useEffect, useMemo, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type ImportJob = {
   id: number;
@@ -46,19 +49,50 @@ type ItemsResp = {
   page_size: number;
 };
 
+type MeProfile = {
+  username?: string;
+};
+
 function fmtTs(v: number | null | undefined): string {
   if (!v) return "-";
   return new Date(v * 1000).toLocaleString();
 }
 
+type ImportJobOptions = {
+  mode?: string;
+  source?: string;
+  workers?: number;
+  target_total?: number;
+  local_pdf_dir?: string;
+  pdf_dir?: string;
+};
+
+function parseOptions(raw: string): ImportJobOptions | null {
+  if (!raw) return null;
+  try {
+    const parsed = JSON.parse(raw);
+    return typeof parsed === "object" && parsed !== null ? (parsed as ImportJobOptions) : null;
+  } catch {
+    return null;
+  }
+}
+
 export default function ImportsPage() {
+  const { tx } = useI18nText();
+  const [token, setToken] = useState("");
+  const [checkingAdmin, setCheckingAdmin] = useState(true);
+  const [isAdmin, setIsAdmin] = useState(false);
+  const [runMode, setRunMode] = useState<"luogu" | "local_pdf_rag">("luogu");
   const [loading, setLoading] = useState(false);
   const [running, setRunning] = useState(false);
   const [error, setError] = useState("");
   const [job, setJob] = useState<ImportJob | null>(null);
   const [items, setItems] = useState<ImportItem[]>([]);
   const [statusFilter, setStatusFilter] = useState("");
-  const [pageSize, setPageSize] = useState(100);
+  const [workers, setWorkers] = useState(3);
+  const [localPdfDir, setLocalPdfDir] = useState("/data/local_pdfs");
+  const [targetTotal, setTargetTotal] = useState(5000);
+  const [pageSize, setPageSize] = useState(50);
   const [clearAllBeforeRun, setClearAllBeforeRun] = useState(true);
 
   const progress = useMemo(() => {
@@ -66,29 +100,30 @@ export default function ImportsPage() {
     return Math.min(100, Math.floor((job.processed_count / job.total_count) * 100));
   }, [job]);
 
-  const loadLatest = async () => {
-    const latest = await apiFetch<LatestResp>("/api/v1/import/jobs/latest");
+  const loadLatest = async (tk: string) => {
+    const latest = await apiFetch<LatestResp>("/api/v1/import/jobs/latest", {}, tk);
     setJob(latest.job ?? null);
     setRunning(Boolean(latest.runner_running) || latest.job?.status === "running");
     return latest.job;
   };
 
-  const loadItems = async (jobId: number) => {
+  const loadItems = async (tk: string, jobId: number) => {
     const params = new URLSearchParams();
     params.set("page", "1");
     params.set("page_size", String(pageSize));
     if (statusFilter) params.set("status", statusFilter);
-    const data = await apiFetch<ItemsResp>(`/api/v1/import/jobs/${jobId}/items?${params.toString()}`);
+    const data = await apiFetch<ItemsResp>(`/api/v1/import/jobs/${jobId}/items?${params.toString()}`, {}, tk);
     setItems(data.items ?? []);
   };
 
   const refresh = async () => {
+    if (!isAdmin || !token) return;
     setLoading(true);
     setError("");
     try {
-      const latestJob = await loadLatest();
+      const latestJob = await loadLatest(token);
       if (latestJob) {
-        await loadItems(latestJob.id);
+        await loadItems(token, latestJob.id);
       } else {
         setItems([]);
       }
@@ -100,159 +135,369 @@ export default function ImportsPage() {
   };
 
   const runImport = async () => {
+    if (!isAdmin || !token) {
+      setError(tx("请先登录管理员账号", "Please sign in with admin account first"));
+      return;
+    }
     setError("");
     try {
-      await apiFetch<{ started: boolean }>("/api/v1/import/jobs/run", {
-        method: "POST",
-        body: JSON.stringify({ clear_all_problems: clearAllBeforeRun }),
-      });
+      const body: Record<string, unknown> = {
+        mode: runMode,
+        workers,
+      };
+      if (runMode === "luogu") {
+        body.clear_all_problems = clearAllBeforeRun;
+      } else {
+        body.local_pdf_dir = localPdfDir;
+        body.target_total = targetTotal;
+      }
+
+      await apiFetch<{ started: boolean }>(
+        "/api/v1/import/jobs/run",
+        {
+          method: "POST",
+          body: JSON.stringify(body),
+        },
+        token
+      );
       await refresh();
     } catch (e: unknown) {
       setError(String(e));
     }
   };
 
-  useEffect(() => {
-    void refresh();
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [pageSize, statusFilter]);
+  const jobOpts = useMemo(() => parseOptions(job?.options_json ?? ""), [job?.options_json]);
 
   useEffect(() => {
+    let canceled = false;
+    const init = async () => {
+      setCheckingAdmin(true);
+      const tk = readToken();
+      setToken(tk);
+      if (!tk) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(tx("请先登录管理员账号", "Please sign in with admin account first"));
+          setCheckingAdmin(false);
+        }
+        return;
+      }
+      try {
+        const me = await apiFetch<MeProfile>("/api/v1/me", {}, tk);
+        const allowed = (me?.username ?? "") === "admin";
+        if (!canceled) {
+          setIsAdmin(allowed);
+          if (!allowed) {
+            setError(tx("仅管理员可查看平台管理信息", "Platform management is visible to admin only"));
+          } else {
+            setError("");
+          }
+        }
+      } catch (e: unknown) {
+        if (!canceled) {
+          setIsAdmin(false);
+          setError(String(e));
+        }
+      } finally {
+        if (!canceled) setCheckingAdmin(false);
+      }
+    };
+    void init();
+    return () => {
+      canceled = true;
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  useEffect(() => {
+    if (!isAdmin || !token) return;
+    void refresh();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [isAdmin, token, pageSize, statusFilter]);
+
+  useEffect(() => {
+    if (!isAdmin || !token) return;
     const timer = setInterval(() => {
       void refresh();
     }, running ? 3000 : 15000);
     return () => clearInterval(timer);
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [running, pageSize, statusFilter]);
+  }, [isAdmin, token, running, pageSize, statusFilter]);
+
+  if (checkingAdmin) {
+    return (
+      <main className="mx-auto max-w-7xl px-3 py-8 text-sm text-zinc-600">
+        {tx("正在校验管理员权限...", "Checking admin access...")}
+      </main>
+    );
+  }
+
+  if (!isAdmin) {
+    return (
+      <main className="mx-auto max-w-4xl px-3 py-8">
+        <h1 className="text-xl font-semibold">{tx("平台管理", "Platform Management")}</h1>
+        <p className="mt-3 text-sm text-red-600">
+          {error || tx("仅管理员可查看此页面", "This page is available for admin only")}
+        </p>
+        <div className="mt-4 flex flex-wrap gap-2 text-sm">
+          <Link className="rounded border bg-white px-3 py-2 hover:bg-zinc-50" href="/auth">
+            {tx("去登录", "Go to Sign In")}
+          </Link>
+          <Link className="rounded border bg-white px-3 py-2 hover:bg-zinc-50" href="/">
+            {tx("返回首页", "Back to Home")}
+          </Link>
+        </div>
+      </main>
+    );
+  }
 
   return (
-    <main className="mx-auto max-w-7xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">题库导入任务（Luogu CSP J/S）</h1>
+    <main className="mx-auto max-w-7xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("题库导入/出题任务", "Import / Generation Jobs")}
+      </h1>
+
+      <section className="mt-4 rounded-xl border bg-white p-4">
+        <h2 className="text-base font-medium">{tx("平台管理快捷入口（原 /admin139）", "Platform Shortcuts (moved from /admin139)")}</h2>
+        <p className="mt-1 text-xs text-zinc-600">
+          {tx("默认管理员账号：admin / whoami139", "Default admin account: admin / whoami139")}
+        </p>
+        <div className="mt-3 grid gap-2 sm:grid-cols-2 lg:grid-cols-5">
+          <Link className="rounded border bg-zinc-50 px-3 py-2 text-sm hover:bg-zinc-100" href="/auth">
+            {tx("登录入口", "Sign In")}
+          </Link>
+          <Link className="rounded border bg-zinc-50 px-3 py-2 text-sm hover:bg-zinc-100" href="/admin-users">
+            {tx("用户积分管理", "User Rating")}
+          </Link>
+          <Link className="rounded border bg-zinc-50 px-3 py-2 text-sm hover:bg-zinc-100" href="/admin-redeem">
+            {tx("积分兑换管理", "Redeem Config")}
+          </Link>
+          <Link className="rounded border bg-zinc-50 px-3 py-2 text-sm hover:bg-zinc-100" href="/backend-logs">
+            {tx("后台日志队列", "Backend Logs")}
+          </Link>
+          <Link className="rounded border bg-zinc-50 px-3 py-2 text-sm hover:bg-zinc-100" href="/api-docs">
+            {tx("API 文档", "API Docs")}
+          </Link>
+        </div>
+      </section>
 
       <div className="mt-4 rounded-xl border bg-white p-4">
         <div className="flex flex-wrap items-center gap-3">
+          <select
+            className="w-full rounded border px-2 py-2 text-sm sm:w-auto"
+            value={runMode}
+            onChange={(e) => setRunMode((e.target.value as "luogu" | "local_pdf_rag") ?? "luogu")}
+            disabled={loading || running}
+          >
+            <option value="luogu">{tx("来源：Luogu CSP J/S", "Source: Luogu CSP J/S")}</option>
+            <option value="local_pdf_rag">{tx("来源：本地 PDF + RAG + LLM 出题", "Source: Local PDF + RAG + LLM")}</option>
+          </select>
+          <label className="flex w-full items-center gap-2 text-sm sm:w-auto">
+            {tx("线程", "Workers")}
+            <input
+              type="number"
+              min={1}
+              max={16}
+              className="w-full rounded border px-2 py-1 sm:w-20"
+              value={workers}
+              onChange={(e) => setWorkers(Math.max(1, Math.min(16, Number(e.target.value) || 1)))}
+              disabled={loading || running}
+            />
+          </label>
+          {runMode === "local_pdf_rag" && (
+            <>
+              <label className="flex w-full items-center gap-2 text-sm sm:w-auto">
+                {tx("PDF目录", "PDF Dir")}
+                <input
+                  className="w-full rounded border px-2 py-1 sm:w-64"
+                  value={localPdfDir}
+                  onChange={(e) => setLocalPdfDir(e.target.value)}
+                  disabled={loading || running}
+                />
+              </label>
+              <label className="flex w-full items-center gap-2 text-sm sm:w-auto">
+                {tx("目标题量", "Target Total")}
+                <input
+                  type="number"
+                  min={1}
+                  max={50000}
+                  className="w-full rounded border px-2 py-1 sm:w-28"
+                  value={targetTotal}
+                  onChange={(e) =>
+                    setTargetTotal(Math.max(1, Math.min(50000, Number(e.target.value) || 1)))
+                  }
+                  disabled={loading || running}
+                />
+              </label>
+            </>
+          )}
           <button
-            className="rounded bg-zinc-900 px-4 py-2 text-white disabled:opacity-50"
+            className="w-full rounded bg-zinc-900 px-4 py-2 text-white disabled:opacity-50 sm:ml-auto sm:w-auto"
             onClick={() => void runImport()}
             disabled={loading || running}
           >
-            {running ? "导入中..." : "启动导入任务"}
+            {running ? tx("导入中...", "Importing...") : tx("启动导入任务", "Start Import Job")}
           </button>
-          <label className="flex items-center gap-2 text-sm">
-            <input
-              type="checkbox"
-              checked={clearAllBeforeRun}
-              onChange={(e) => setClearAllBeforeRun(e.target.checked)}
-            />
-            启动前清空历史题库
-          </label>
+          {runMode === "luogu" && (
+            <label className="flex w-full items-center gap-2 text-sm sm:w-auto">
+              <input
+                type="checkbox"
+                checked={clearAllBeforeRun}
+                onChange={(e) => setClearAllBeforeRun(e.target.checked)}
+              />
+              {tx("启动前清空历史题库", "Clear old problem set before start")}
+            </label>
+          )}
           <button className="rounded border px-3 py-2 text-sm" onClick={() => void refresh()} disabled={loading}>
-            刷新
+            {tx("刷新", "Refresh")}
           </button>
           <span className={`text-sm ${running ? "text-emerald-700" : "text-zinc-600"}`}>
-            {running ? "运行中" : "空闲"}
+            {running ? tx("运行中", "Running") : tx("空闲", "Idle")}
           </span>
         </div>
-        <p className="mt-2 text-xs text-zinc-500">
-          默认按后端配置以 3 线程执行，抓取洛谷 CSP-J/CSP-S/NOIP 标签题；容器重启后会自动触发导入（可通过环境变量关闭）。
-        </p>
+        {runMode === "luogu" && (
+          <p className="mt-2 text-xs text-zinc-500">
+            {tx(
+              "抓取洛谷 CSP-J/CSP-S/NOIP 标签题；容器重启后可自动触发（可通过环境变量关闭）。",
+              "Fetch Luogu problems tagged CSP-J/CSP-S/NOIP. It can auto-start after container restart (configurable via env)."
+            )}
+          </p>
+        )}
+        {runMode === "local_pdf_rag" && (
+          <p className="mt-2 text-xs text-zinc-500">
+            {tx(
+              "从本地 PDF 提取文本做 RAG，调用 LLM 生成 CSP-J/S 题目，按现有题库难度分布补齐到目标题量并自动去重跳过。",
+              "Extract text from local PDFs for RAG, then call LLM to generate CSP-J/S problems with dedupe and target distribution."
+            )}
+          </p>
+        )}
       </div>
 
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
       <section className="mt-4 rounded-xl border bg-white p-4">
-        <h2 className="text-lg font-medium">最新任务</h2>
-        {!job && <p className="mt-2 text-sm text-zinc-500">暂无任务记录</p>}
+        <h2 className="text-lg font-medium">{tx("最新任务", "Latest Job")}</h2>
+        {!job && <p className="mt-2 text-sm text-zinc-500">{tx("暂无任务记录", "No job records")}</p>}
         {job && (
           <div className="mt-3 space-y-2 text-sm">
             <p>
-              任务 #{job.id} · 状态 <b>{job.status}</b> · 触发方式 {job.trigger}
+              {tx("任务", "Job")} #{job.id} · {tx("状态", "Status")} <b>{job.status}</b> · {tx("触发方式", "Trigger")} {job.trigger}
+            </p>
+            <p className="text-zinc-600">
+              {tx("模式", "Mode")} {jobOpts?.mode || jobOpts?.source || "luogu"} · {tx("线程", "Workers")} {jobOpts?.workers ?? "-"}
+              {typeof jobOpts?.target_total === "number" && ` · ${tx("目标题量", "Target total")} ${jobOpts.target_total}`}
+              {(jobOpts?.local_pdf_dir || jobOpts?.pdf_dir) &&
+                ` · ${tx("PDF目录", "PDF dir")} ${jobOpts.local_pdf_dir || jobOpts.pdf_dir}`}
             </p>
             <p>
-              总数 {job.total_count}，已处理 {job.processed_count}，成功 {job.success_count}，失败 {job.failed_count}
+              {tx("总数", "Total")} {job.total_count}，{tx("已处理", "Processed")} {job.processed_count}，{tx("成功", "Success")} {job.success_count}，{tx("失败", "Failed")} {job.failed_count}
             </p>
             <div className="h-2 w-full rounded bg-zinc-100">
               <div className="h-2 rounded bg-emerald-500" style={{ width: `${progress}%` }} />
             </div>
             <p className="text-zinc-600">
-              进度 {progress}% · 开始 {fmtTs(job.started_at)} · 结束 {fmtTs(job.finished_at)}
+              {tx("进度", "Progress")} {progress}% · {tx("开始", "Start")} {fmtTs(job.started_at)} · {tx("结束", "End")} {fmtTs(job.finished_at)}
             </p>
-            {job.last_error && <p className="text-red-600">最近错误：{job.last_error}</p>}
+            {job.last_error && <p className="text-red-600">{tx("最近错误：", "Latest error: ")}{job.last_error}</p>}
           </div>
         )}
       </section>
 
       <section className="mt-4 rounded-xl border bg-white p-4">
         <div className="flex flex-wrap items-center gap-3">
-          <h2 className="text-lg font-medium">任务明细</h2>
+          <h2 className="text-lg font-medium">{tx("任务明细", "Job Items")}</h2>
           <select
             className="rounded border px-2 py-1 text-sm"
             value={statusFilter}
             onChange={(e) => setStatusFilter(e.target.value)}
           >
-            <option value="">全部状态</option>
+            <option value="">{tx("全部状态", "All Status")}</option>
             <option value="queued">queued</option>
             <option value="running">running</option>
             <option value="success">success</option>
             <option value="failed">failed</option>
+            <option value="skipped">skipped</option>
+            <option value="interrupted">interrupted</option>
           </select>
           <select
             className="rounded border px-2 py-1 text-sm"
             value={pageSize}
             onChange={(e) => setPageSize(Number(e.target.value))}
           >
-            <option value={50}>50 条</option>
-            <option value={100}>100 条</option>
-            <option value={200}>200 条</option>
+            <option value={50}>{tx("50 条", "50 rows")}</option>
+            <option value={100}>{tx("100 条", "100 rows")}</option>
+            <option value={200}>{tx("200 条", "200 rows")}</option>
           </select>
         </div>
 
-        <div className="mt-3 overflow-x-auto">
-          <table className="min-w-full text-xs">
-            <thead className="bg-zinc-100 text-left">
-              <tr>
-                <th className="px-2 py-2">ID</th>
-                <th className="px-2 py-2">路径</th>
-                <th className="px-2 py-2">状态</th>
-                <th className="px-2 py-2">标题</th>
-                <th className="px-2 py-2">难度</th>
-                <th className="px-2 py-2">题目ID</th>
-                <th className="px-2 py-2">错误</th>
-              </tr>
-            </thead>
-            <tbody>
-              {items.map((item) => (
-                <tr key={item.id} className="border-t align-top">
-                  <td className="px-2 py-2">{item.id}</td>
-                  <td className="max-w-[400px] px-2 py-2">
-                    <div className="truncate" title={item.source_path}>
-                      {item.source_path}
-                    </div>
-                  </td>
-                  <td className="px-2 py-2">{item.status}</td>
-                  <td className="max-w-[220px] px-2 py-2">
-                    <div className="truncate" title={item.title}>
-                      {item.title || "-"}
-                    </div>
-                  </td>
-                  <td className="px-2 py-2">{item.difficulty || "-"}</td>
-                  <td className="px-2 py-2">{item.problem_id ?? "-"}</td>
-                  <td className="max-w-[320px] px-2 py-2 text-red-600">
-                    <div className="truncate" title={item.error_text}>
-                      {item.error_text || "-"}
-                    </div>
-                  </td>
-                </tr>
-              ))}
-              {items.length === 0 && (
+        <div className="mt-3 rounded-lg border">
+          <div className="divide-y md:hidden">
+            {items.map((item) => (
+              <article key={item.id} className="space-y-1 p-3 text-xs">
+                <div className="flex items-center justify-between gap-2">
+                  <p className="font-medium">
+                    {tx("明细", "Detail")} #{item.id}
+                  </p>
+                  <span>{item.status}</span>
+                </div>
+                <p className="break-all text-zinc-600">{tx("路径：", "Path: ")}{item.source_path}</p>
+                <p className="text-zinc-600">{tx("标题：", "Title: ")}{item.title || "-"}</p>
+                <p className="text-zinc-600">
+                  {tx("难度：", "Difficulty: ")}{item.difficulty || "-"} · {tx("题目ID：", "Problem ID: ")}{item.problem_id ?? "-"}
+                </p>
+                {item.error_text && <p className="break-words text-red-600">{tx("错误：", "Error: ")}{item.error_text}</p>}
+              </article>
+            ))}
+            {items.length === 0 && <p className="px-3 py-4 text-center text-sm text-zinc-500">{tx("暂无明细", "No details")}</p>}
+          </div>
+
+          <div className="hidden overflow-x-auto md:block">
+            <table className="min-w-full text-xs">
+              <thead className="bg-zinc-100 text-left">
                 <tr>
-                  <td className="px-2 py-4 text-center text-zinc-500" colSpan={7}>
-                    暂无明细
-                  </td>
+                  <th className="px-2 py-2">ID</th>
+                  <th className="px-2 py-2">{tx("路径", "Path")}</th>
+                  <th className="px-2 py-2">{tx("状态", "Status")}</th>
+                  <th className="px-2 py-2">{tx("标题", "Title")}</th>
+                  <th className="px-2 py-2">{tx("难度", "Difficulty")}</th>
+                  <th className="px-2 py-2">{tx("题目ID", "Problem ID")}</th>
+                  <th className="px-2 py-2">{tx("错误", "Error")}</th>
                 </tr>
-              )}
-            </tbody>
-          </table>
+              </thead>
+              <tbody>
+                {items.map((item) => (
+                  <tr key={item.id} className="border-t align-top">
+                    <td className="px-2 py-2">{item.id}</td>
+                    <td className="max-w-[400px] px-2 py-2">
+                      <div className="truncate" title={item.source_path}>
+                        {item.source_path}
+                      </div>
+                    </td>
+                    <td className="px-2 py-2">{item.status}</td>
+                    <td className="max-w-[220px] px-2 py-2">
+                      <div className="truncate" title={item.title}>
+                        {item.title || "-"}
+                      </div>
+                    </td>
+                    <td className="px-2 py-2">{item.difficulty || "-"}</td>
+                    <td className="px-2 py-2">{item.problem_id ?? "-"}</td>
+                    <td className="max-w-[320px] px-2 py-2 text-red-600">
+                      <div className="truncate" title={item.error_text}>
+                        {item.error_text || "-"}
+                      </div>
+                    </td>
+                  </tr>
+                ))}
+                {items.length === 0 && (
+                  <tr>
+                    <td className="px-2 py-4 text-center text-zinc-500" colSpan={7}>
+                      {tx("暂无明细", "No details")}
+                    </td>
+                  </tr>
+                )}
+              </tbody>
+            </table>
+          </div>
         </div>
       </section>
     </main>

frontend/src/app/kb/[slug]/page.tsx

@@ -4,7 +4,9 @@ import Link from "next/link";
 import { useParams } from "next/navigation";
 import { useEffect, useMemo, useState } from "react";
 
+import { MarkdownRenderer } from "@/components/markdown-renderer";
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type Article = {
   id: number;
@@ -20,6 +22,7 @@ type DetailResp = {
 };
 
 export default function KbDetailPage() {
+  const { tx } = useI18nText();
   const params = useParams<{ slug: string }>();
   const slug = useMemo(() => params.slug, [params.slug]);
 
@@ -44,29 +47,41 @@ export default function KbDetailPage() {
   }, [slug]);
 
   return (
-    <main className="mx-auto max-w-5xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">知识库文章</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
+    <main className="mx-auto max-w-5xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("知识库文章", "Knowledge Article")}
+      </h1>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
       {data && (
         <div className="mt-4 space-y-4">
           <section className="rounded-xl border bg-white p-4">
             <h2 className="text-xl font-medium">{data.article.title}</h2>
-            <pre className="mt-3 whitespace-pre-wrap text-sm">{data.article.content_md}</pre>
+            <p className="mt-1 text-xs text-zinc-500">
+              {tx("更新时间：", "Updated: ")}
+              {new Date(data.article.created_at * 1000).toLocaleString()}
+            </p>
+            <div className="mt-3">
+              <MarkdownRenderer markdown={data.article.content_md} />
+            </div>
           </section>
 
           <section className="rounded-xl border bg-white p-4">
-            <h3 className="text-sm font-medium">关联题目</h3>
-            <ul className="mt-2 space-y-2 text-sm">
-              {data.related_problems.map((p) => (
-                <li key={p.problem_id}>
-                  <Link className="text-blue-600 underline" href={`/problems/${p.problem_id}`}>
-                    #{p.problem_id} {p.title}
-                  </Link>
-                </li>
-              ))}
-            </ul>
+            <h3 className="text-sm font-medium">{tx("关联题目", "Related Problems")}</h3>
+            {data.related_problems.length ? (
+              <ul className="mt-2 space-y-2 text-sm">
+                {data.related_problems.map((p) => (
+                  <li key={p.problem_id}>
+                    <Link className="text-blue-600 underline" href={`/problems/${p.problem_id}`}>
+                      #{p.problem_id} {p.title}
+                    </Link>
+                  </li>
+                ))}
+              </ul>
+            ) : (
+              <p className="mt-2 text-sm text-zinc-500">{tx("暂无关联题目", "No related problems")}</p>
+            )}
           </section>
         </div>
       )}

frontend/src/app/kb/page.tsx

@@ -1,9 +1,11 @@
 "use client";
 
 import Link from "next/link";
-import { useEffect, useState } from "react";
+import { useCallback, useEffect, useMemo, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type Article = {
   id: number;
@@ -12,47 +14,263 @@ type Article = {
   created_at: number;
 };
 
+type KbRefreshStatus = {
+  running: boolean;
+  last_command: string;
+  last_trigger: string;
+  last_exit_code: number | null;
+  last_started_at: number;
+  last_finished_at: number;
+};
+
+type TriggerKbRefreshResp = KbRefreshStatus & {
+  started: boolean;
+  message: string;
+};
+
+function fmtTs(v: number | null | undefined): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
 export default function KbListPage() {
+  const { tx } = useI18nText();
+  const [refreshToken, setRefreshToken] = useState("");
+  const [canManageRefresh, setCanManageRefresh] = useState(false);
   const [items, setItems] = useState<Article[]>([]);
   const [loading, setLoading] = useState(false);
+  const [statusLoading, setStatusLoading] = useState(false);
+  const [triggerLoading, setTriggerLoading] = useState(false);
   const [error, setError] = useState("");
+  const [hint, setHint] = useState("");
+  const [refreshStatus, setRefreshStatus] = useState<KbRefreshStatus | null>(null);
+  const [lastSyncedFinishedAt, setLastSyncedFinishedAt] = useState(0);
 
-  useEffect(() => {
-    const load = async () => {
-      setLoading(true);
-      setError("");
-      try {
-        const data = await apiFetch<Article[]>("/api/v1/kb/articles");
-        setItems(data);
-      } catch (e: unknown) {
-        setError(String(e));
-      } finally {
-        setLoading(false);
-      }
+  const grouped = useMemo(() => {
+    const buckets: Record<string, Article[]> = {
+      roadmap: [],
+      cpp: [],
+      cspj: [],
+      csps: [],
+      other: [],
     };
-    void load();
+    for (const article of items) {
+      const slug = article.slug.toLowerCase();
+      if (slug.includes("roadmap")) {
+        buckets.roadmap.push(article);
+      } else if (slug.includes("cpp")) {
+        buckets.cpp.push(article);
+      } else if (slug.includes("csp-j") || slug.includes("cspj")) {
+        buckets.cspj.push(article);
+      } else if (slug.includes("csp-s") || slug.includes("csps")) {
+        buckets.csps.push(article);
+      } else {
+        buckets.other.push(article);
+      }
+    }
+    return buckets;
+  }, [items]);
+
+  const loadArticles = useCallback(async () => {
+    setLoading(true);
+    setError("");
+    try {
+      const data = await apiFetch<Article[]>("/api/v1/kb/articles");
+      setItems(data);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setLoading(false);
+    }
   }, []);
 
-  return (
-    <main className="mx-auto max-w-5xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">学习知识库</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
-      {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
+  const loadStatus = useCallback(async () => {
+    if (!canManageRefresh || !refreshToken) {
+      setRefreshStatus(null);
+      return;
+    }
+    setStatusLoading(true);
+    try {
+      const data = await apiFetch<KbRefreshStatus>("/api/v1/backend/kb/refresh", {}, refreshToken);
+      setRefreshStatus(data);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setStatusLoading(false);
+    }
+  }, [canManageRefresh, refreshToken]);
 
-      <div className="mt-4 space-y-3">
-        {items.map((a) => (
-          <Link
-            key={a.slug}
-            href={`/kb/${a.slug}`}
-            className="block rounded-xl border bg-white p-4 hover:border-zinc-400"
+  useEffect(() => {
+    let canceled = false;
+    const refreshAdminState = async () => {
+      const tk = readToken();
+      if (!tk) {
+        if (!canceled) {
+          setRefreshToken("");
+          setCanManageRefresh(false);
+        }
+        return;
+      }
+      try {
+        const me = await apiFetch<{ username?: string }>("/api/v1/me", {}, tk);
+        if (!canceled) {
+          const isAdmin = (me?.username ?? "") === "admin";
+          setCanManageRefresh(isAdmin);
+          setRefreshToken(isAdmin ? tk : "");
+        }
+      } catch {
+        if (!canceled) {
+          setRefreshToken("");
+          setCanManageRefresh(false);
+        }
+      }
+    };
+    void refreshAdminState();
+    const onFocus = () => {
+      void refreshAdminState();
+    };
+    window.addEventListener("focus", onFocus);
+    return () => {
+      canceled = true;
+      window.removeEventListener("focus", onFocus);
+    };
+  }, []);
+
+  useEffect(() => {
+    void loadArticles();
+    void loadStatus();
+  }, [loadArticles, loadStatus]);
+
+  useEffect(() => {
+    const timer = setInterval(() => {
+      void loadStatus();
+    }, 5000);
+    return () => clearInterval(timer);
+  }, [loadStatus]);
+
+  useEffect(() => {
+    if (!refreshStatus) return;
+    if (
+      !refreshStatus.running &&
+      refreshStatus.last_finished_at > 0 &&
+      refreshStatus.last_finished_at > lastSyncedFinishedAt
+    ) {
+      setLastSyncedFinishedAt(refreshStatus.last_finished_at);
+      void loadArticles();
+    }
+  }, [lastSyncedFinishedAt, loadArticles, refreshStatus]);
+
+  const triggerRefresh = async () => {
+    if (!canManageRefresh || !refreshToken) {
+      setError(tx("仅管理员可执行一键更新资料", "Only admin can trigger material refresh"));
+      return;
+    }
+    setTriggerLoading(true);
+    setError("");
+    setHint("");
+    try {
+      const data = await apiFetch<TriggerKbRefreshResp>(
+        "/api/v1/backend/kb/refresh",
+        {
+          method: "POST",
+          body: JSON.stringify({}),
+        },
+        refreshToken
+      );
+      setRefreshStatus({
+        running: data.running,
+        last_command: data.last_command,
+        last_trigger: data.last_trigger,
+        last_exit_code: data.last_exit_code,
+        last_started_at: data.last_started_at,
+        last_finished_at: data.last_finished_at,
+      });
+      setHint(
+        data.message || (data.started ? tx("已触发异步更新", "Async refresh started") : tx("当前已有任务在运行", "A refresh job is already running"))
+      );
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setTriggerLoading(false);
+    }
+  };
+
+  return (
+    <main className="mx-auto max-w-5xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <div className="flex flex-wrap items-center justify-between gap-3">
+        <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">{tx("学习知识库", "Knowledge Base")}</h1>
+        {canManageRefresh ? (
+          <button
+            className="rounded border px-3 py-1 text-sm disabled:opacity-50"
+            disabled={triggerLoading || refreshStatus?.running}
+            onClick={() => void triggerRefresh()}
           >
-            <h2 className="text-lg font-medium">{a.title}</h2>
-            <p className="mt-1 text-xs text-zinc-500">
-              slug: {a.slug} · {new Date(a.created_at * 1000).toLocaleString()}
-            </p>
-          </Link>
-        ))}
+            {triggerLoading
+              ? tx("更新触发中...", "Triggering...")
+              : refreshStatus?.running
+                ? tx("资料更新中...", "Refreshing...")
+                : tx("手动一键更新资料", "Manual Refresh")}
+          </button>
+        ) : (
+          <span className="text-xs text-zinc-500">
+            {tx("资料更新由管理员维护", "Material refresh is managed by admin")}
+          </span>
+        )}
       </div>
+      <p className="mt-2 text-sm text-zinc-600">
+        {tx(
+          "已整理 C++ 基础、CSP-J、CSP-S 学习资料，可按阶段逐步学习。",
+          "Curated learning materials for C++ fundamentals, CSP-J, and CSP-S."
+        )}
+      </p>
+      <p className="mt-1 text-xs text-zinc-500">
+        {canManageRefresh
+          ? tx("更新状态：", "Refresh status:")
+          : tx("更新状态：仅管理员可查看与触发。", "Refresh status: admin only.")}
+        {canManageRefresh &&
+          (statusLoading && !refreshStatus
+            ? tx("读取中...", "Loading...")
+            : refreshStatus?.running
+              ? tx(`运行中（开始于 ${fmtTs(refreshStatus.last_started_at)}）`, `Running (started at ${fmtTs(refreshStatus.last_started_at)})`)
+              : tx(`空闲（最近结束 ${fmtTs(refreshStatus?.last_finished_at ?? null)}，退出码 ${
+                  refreshStatus?.last_exit_code ?? "-"
+                }）`, `Idle (last finished ${fmtTs(refreshStatus?.last_finished_at ?? null)}, exit code ${
+                  refreshStatus?.last_exit_code ?? "-"
+                })`))}
+      </p>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
+      {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
+      {hint && <p className="mt-3 text-sm text-emerald-700">{hint}</p>}
+
+      <section className="mt-4 space-y-5">
+        {[
+          ["roadmap", tx("学习总路线", "Learning Roadmap")],
+          ["cpp", tx("C++ 基础", "C++ Fundamentals")],
+          ["cspj", "CSP-J"],
+          ["csps", "CSP-S"],
+          ["other", tx("其他资料", "Other Resources")],
+        ].map(([key, label]) => {
+          const group = grouped[key] ?? [];
+          if (!group.length) return null;
+          return (
+            <div key={key} className="space-y-3">
+              <h2 className="text-sm font-semibold text-zinc-700">{label}</h2>
+              {group.map((a) => (
+                <Link
+                  key={a.slug}
+                  href={`/kb/${a.slug}`}
+                  className="block rounded-xl border bg-white p-4 hover:border-zinc-400"
+                >
+                  <h3 className="text-lg font-medium">{a.title}</h3>
+                  <p className="mt-1 text-xs text-zinc-500">
+                    slug: {a.slug} · {new Date(a.created_at * 1000).toLocaleString()}
+                  </p>
+                </Link>
+              ))}
+            </div>
+          );
+        })}
+      </section>
     </main>
   );
 }

frontend/src/app/layout.tsx

@@ -1,13 +1,17 @@
 import type { Metadata } from "next";
 import { AppNav } from "@/components/app-nav";
+import { MobileTabBar } from "@/components/mobile-tab-bar";
+import { UiPreferenceProvider } from "@/components/ui-preference-provider";
 import "katex/dist/katex.min.css";
 import "highlight.js/styles/github-dark.css";
 import "swagger-ui-react/swagger-ui.css";
+import "@/themes/default/theme.css";
+import "@/themes/minecraft/theme.css";
 import "./globals.css";
 
 export const metadata: Metadata = {
-  title: "CSP 在线学习与竞赛平台",
-  description: "题库、错题本、模拟竞赛、知识库与在线 C++ 运行",
+  title: "CSP Online Learning & Contest Platform",
+  description: "Problems, wrong-book review, contests, knowledge base, and C++ runner.",
 };
 
 export default function RootLayout({
@@ -16,10 +20,13 @@ export default function RootLayout({
   children: React.ReactNode;
 }>) {
   return (
-    <html lang="zh-CN">
+    <html lang="en" suppressHydrationWarning>
       <body className="antialiased">
-        <AppNav />
-        {children}
+        <UiPreferenceProvider>
+          <AppNav />
+          <div className="pb-[calc(3.8rem+env(safe-area-inset-bottom))] md:pb-0">{children}</div>
+          <MobileTabBar />
+        </UiPreferenceProvider>
       </body>
     </html>
   );

frontend/src/app/leaderboard/page.tsx

@@ -3,6 +3,7 @@
 import { useEffect, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type Row = {
   user_id: number;
@@ -12,6 +13,7 @@ type Row = {
 };
 
 export default function LeaderboardPage() {
+  const { tx } = useI18nText();
   const [items, setItems] = useState<Row[]>([]);
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState("");
@@ -33,34 +35,65 @@ export default function LeaderboardPage() {
   }, []);
 
   return (
-    <main className="mx-auto max-w-4xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">全站排行榜</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
+    <main className="mx-auto max-w-4xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("全站排行榜", "Global Leaderboard")}
+      </h1>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
-      <div className="mt-4 overflow-x-auto rounded-xl border bg-white">
-        <table className="min-w-full text-sm">
-          <thead className="bg-zinc-100 text-left">
-            <tr>
-              <th className="px-3 py-2">排名</th>
-              <th className="px-3 py-2">用户</th>
-              <th className="px-3 py-2">Rating</th>
-              <th className="px-3 py-2">注册时间</th>
-            </tr>
-          </thead>
-          <tbody>
-            {items.map((row, i) => (
-              <tr key={row.user_id} className="border-t">
-                <td className="px-3 py-2">{i + 1}</td>
-                <td className="px-3 py-2">{row.username}</td>
-                <td className="px-3 py-2">{row.rating}</td>
-                <td className="px-3 py-2">
-                  {new Date(row.created_at * 1000).toLocaleString()}
-                </td>
+      <div className="mt-4 rounded-xl border bg-white">
+        <div className="divide-y md:hidden">
+          {items.map((row, i) => (
+            <article key={row.user_id} className="space-y-1 p-3 text-sm">
+              <p className="font-medium">
+                #{i + 1} · {row.username}
+              </p>
+              <p className="text-xs text-zinc-600">Rating: {row.rating}</p>
+              <p className="text-xs text-zinc-500">
+                {tx("注册时间：", "Registered: ")}
+                {new Date(row.created_at * 1000).toLocaleString()}
+              </p>
+            </article>
+          ))}
+          {!loading && items.length === 0 && (
+            <p className="px-3 py-5 text-center text-sm text-zinc-500">
+              {tx("暂无排行数据", "No ranking data yet")}
+            </p>
+          )}
+        </div>
+
+        <div className="hidden overflow-x-auto md:block">
+          <table className="min-w-full text-sm">
+            <thead className="bg-zinc-100 text-left">
+              <tr>
+                <th className="px-3 py-2">{tx("排名", "Rank")}</th>
+                <th className="px-3 py-2">{tx("用户", "User")}</th>
+                <th className="px-3 py-2">Rating</th>
+                <th className="px-3 py-2">{tx("注册时间", "Registered At")}</th>
               </tr>
-            ))}
-          </tbody>
-        </table>
+            </thead>
+            <tbody>
+              {items.map((row, i) => (
+                <tr key={row.user_id} className="border-t">
+                  <td className="px-3 py-2">{i + 1}</td>
+                  <td className="px-3 py-2">{row.username}</td>
+                  <td className="px-3 py-2">{row.rating}</td>
+                  <td className="px-3 py-2">
+                    {new Date(row.created_at * 1000).toLocaleString()}
+                  </td>
+                </tr>
+              ))}
+              {!loading && items.length === 0 && (
+                <tr>
+                  <td className="px-3 py-5 text-center text-zinc-500" colSpan={4}>
+                    {tx("暂无排行数据", "No ranking data yet")}
+                  </td>
+                </tr>
+              )}
+            </tbody>
+          </table>
+        </div>
       </div>
     </main>
   );

frontend/src/app/me/page.tsx

@@ -4,6 +4,7 @@ import { useEffect, useMemo, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
 import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type Me = {
   id: number;
@@ -61,6 +62,7 @@ function fmtTs(v: number | null | undefined): string {
 }
 
 export default function MePage() {
+  const { isZh, tx } = useI18nText();
   const [token, setToken] = useState("");
   const [profile, setProfile] = useState<Me | null>(null);
   const [items, setItems] = useState<RedeemItem[]>([]);
@@ -92,6 +94,38 @@ export default function MePage() {
 
   const totalCost = useMemo(() => Math.max(0, unitCost * Math.max(1, quantity)), [quantity, unitCost]);
 
+  const taskTitle = (task: DailyTaskItem): string => {
+    if (isZh) return task.title;
+    if (task.code === "login_checkin") return "Daily Sign-in";
+    if (task.code === "daily_submit") return "Daily Submission";
+    if (task.code === "first_ac") return "Solve One Problem";
+    if (task.code === "code_quality") return "Code Quality";
+    return task.title;
+  };
+
+  const taskDesc = (task: DailyTaskItem): string => {
+    if (isZh) return task.description;
+    if (task.code === "login_checkin") return "Sign in once today to get 1 point.";
+    if (task.code === "daily_submit") return "Submit once today to get 1 point.";
+    if (task.code === "first_ac") return "Get AC once today to get 1 point.";
+    if (task.code === "code_quality") return "Submit code longer than 10 lines once today to get 1 point.";
+    return task.description;
+  };
+
+  const itemName = (name: string): string => {
+    if (isZh) return name;
+    if (name === "私人玩游戏时间") return "Private Game Time";
+    return name;
+  };
+
+  const itemDesc = (text: string): string => {
+    if (isZh) return text;
+    if (text === "全局用户可兑换：假期 1 小时 5 Rating；学习日/非节假日 1 小时 25 Rating。") {
+      return "Global redeem item: holiday 1 hour = 5 rating; study day/non-holiday 1 hour = 25 rating.";
+    }
+    return text;
+  };
+
   const loadAll = async () => {
     setLoading(true);
     setError("");
@@ -99,7 +133,7 @@ export default function MePage() {
     try {
       const tk = readToken();
       setToken(tk);
-      if (!tk) throw new Error("请先登录");
+      if (!tk) throw new Error(tx("请先登录", "Please sign in first"));
 
       const [me, redeemItems, redeemRecords, daily] = await Promise.all([
         apiFetch<Me>("/api/v1/me", {}, tk),
@@ -127,6 +161,7 @@ export default function MePage() {
 
   useEffect(() => {
     void loadAll();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
   const redeem = async () => {
@@ -134,9 +169,11 @@ export default function MePage() {
     setError("");
     setMsg("");
     try {
-      if (!token) throw new Error("请先登录");
-      if (!selectedItemId) throw new Error("请选择兑换物品");
-      if (!Number.isFinite(quantity) || quantity <= 0) throw new Error("兑换数量必须大于 0");
+      if (!token) throw new Error(tx("请先登录", "Please sign in first"));
+      if (!selectedItemId) throw new Error(tx("请选择兑换物品", "Please select a redeem item"));
+      if (!Number.isFinite(quantity) || quantity <= 0) {
+        throw new Error(tx("兑换数量必须大于 0", "Quantity must be greater than 0"));
+      }
 
       const created = await apiFetch<RedeemCreateResp>(
         "/api/v1/me/redeem/records",
@@ -153,9 +190,13 @@ export default function MePage() {
       );
 
       setMsg(
-        `兑换成功：${created.item_name} × ${created.quantity}，扣除 ${created.total_cost} 积分${
-          typeof created.rating_after === "number" ? `，当前 Rating ${created.rating_after}` : ""
-        }。`
+        isZh
+          ? `兑换成功：${created.item_name} × ${created.quantity}，扣除 ${created.total_cost} 积分${
+              typeof created.rating_after === "number" ? `，当前 Rating ${created.rating_after}` : ""
+            }。`
+          : `Redeemed successfully: ${itemName(created.item_name)} × ${created.quantity}, cost ${created.total_cost} rating${
+              typeof created.rating_after === "number" ? `, current rating ${created.rating_after}` : ""
+            }.`
       );
       setNote("");
       await loadAll();
@@ -168,25 +209,28 @@ export default function MePage() {
 
   return (
     <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
-      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">我的信息与积分兑换</h1>
-      {loading && <p className="mt-3 text-sm text-zinc-500">加载中...</p>}
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("我的信息与积分兑换", "My Profile & Redeem")}
+      </h1>
+      {loading && <p className="mt-3 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
       {msg && <p className="mt-3 text-sm text-emerald-700">{msg}</p>}
 
       {profile && (
         <section className="mt-4 rounded-xl border bg-white p-4 text-sm">
           <p>ID: {profile.id}</p>
-          <p>用户名: {profile.username}</p>
+          <p>{tx("用户名", "Username")}: {profile.username}</p>
           <p>Rating: {profile.rating}</p>
-          <p>创建时间: {fmtTs(profile.created_at)}</p>
+          <p>{tx("创建时间", "Created At")}: {fmtTs(profile.created_at)}</p>
         </section>
       )}
 
       <section className="mt-4 rounded-xl border bg-white p-4">
         <div className="flex flex-wrap items-center justify-between gap-2">
-          <h2 className="text-base font-semibold">每日任务</h2>
+          <h2 className="text-base font-semibold">{tx("每日任务", "Daily Tasks")}</h2>
           <p className="text-xs text-zinc-600">
-            {dailyDayKey ? `${dailyDayKey} · ` : ""}已获 {dailyGainedReward}/{dailyTotalReward} 分
+            {dailyDayKey ? `${dailyDayKey} · ` : ""}
+            {tx("已获", "Earned")} {dailyGainedReward}/{dailyTotalReward} {tx("分", "pts")}
           </p>
         </div>
         <div className="mt-3 divide-y">
@@ -194,68 +238,82 @@ export default function MePage() {
             <article key={task.code} className="py-2 text-sm">
               <div className="flex items-center justify-between gap-2">
                 <p className="font-medium">
-                  {task.title} · +{task.reward}
+                  {taskTitle(task)} · +{task.reward}
                 </p>
                 <span
                   className={`rounded px-2 py-0.5 text-xs ${
                     task.completed ? "bg-emerald-100 text-emerald-700" : "bg-zinc-100 text-zinc-600"
                   }`}
                 >
-                  {task.completed ? "已完成" : "未完成"}
+                  {task.completed ? tx("已完成", "Completed") : tx("未完成", "Incomplete")}
                 </span>
               </div>
-              <p className="mt-1 text-xs text-zinc-600">{task.description}</p>
+              <p className="mt-1 text-xs text-zinc-600">{taskDesc(task)}</p>
               {task.completed && (
-                <p className="mt-1 text-xs text-zinc-500">完成时间：{fmtTs(task.completed_at)}</p>
+                <p className="mt-1 text-xs text-zinc-500">
+                  {tx("完成时间：", "Completed At: ")}
+                  {fmtTs(task.completed_at)}
+                </p>
               )}
             </article>
           ))}
           {!loading && dailyTasks.length === 0 && (
-            <p className="py-3 text-sm text-zinc-500">今日任务尚未初始化，请稍后刷新。</p>
+            <p className="py-3 text-sm text-zinc-500">
+              {tx("今日任务尚未初始化，请稍后刷新。", "Today's tasks are not initialized yet. Please refresh later.")}
+            </p>
           )}
         </div>
       </section>
 
       <section className="mt-4 rounded-xl border bg-white p-4">
-        <h2 className="text-base font-semibold">积分兑换物品</h2>
+        <h2 className="text-base font-semibold">{tx("积分兑换物品", "Redeem Items")}</h2>
         <p className="mt-1 text-xs text-zinc-600">
-          示例规则：私人玩游戏时间（假期 1 小时=5 积分；学习日/非节假日 1 小时=25 积分）
+          {tx(
+            "示例规则：私人玩游戏时间（假期 1 小时=5 积分；学习日/非节假日 1 小时=25 积分）",
+            "Sample rule: Private Game Time (holiday 1h=5 points; study day/non-holiday 1h=25 points)"
+          )}
         </p>
 
         <div className="mt-3 grid gap-3 md:grid-cols-2">
           {items.map((item) => (
             <article key={item.id} className="rounded border bg-zinc-50 p-3 text-sm">
               <div className="flex items-start justify-between gap-2">
-                <p className="font-medium">{item.name}</p>
+                <p className="font-medium">{itemName(item.name)}</p>
                 <button
                   className="rounded border px-2 py-1 text-xs hover:bg-zinc-100"
                   onClick={() => setSelectedItemId(item.id)}
                 >
-                  选中
+                  {tx("选中", "Select")}
                 </button>
               </div>
-              <p className="mt-1 text-xs text-zinc-600">{item.description || "-"}</p>
-              <p className="mt-1 text-xs text-zinc-700">假期：{item.holiday_cost} / {item.unit_label}</p>
-              <p className="text-xs text-zinc-700">学习日：{item.studyday_cost} / {item.unit_label}</p>
+              <p className="mt-1 text-xs text-zinc-600">{itemDesc(item.description) || "-"}</p>
+              <p className="mt-1 text-xs text-zinc-700">
+                {tx("假期", "Holiday")}: {item.holiday_cost} / {item.unit_label}
+              </p>
+              <p className="text-xs text-zinc-700">
+                {tx("学习日", "Study Day")}: {item.studyday_cost} / {item.unit_label}
+              </p>
             </article>
           ))}
           {!loading && items.length === 0 && (
-            <p className="text-sm text-zinc-500">管理员尚未配置可兑换物品。</p>
+            <p className="text-sm text-zinc-500">
+              {tx("管理员尚未配置可兑换物品。", "No redeem items configured by admin yet.")}
+            </p>
           )}
         </div>
 
         <div className="mt-4 rounded-lg border p-3">
-          <h3 className="text-sm font-medium">兑换表单</h3>
+          <h3 className="text-sm font-medium">{tx("兑换表单", "Redeem Form")}</h3>
           <div className="mt-2 grid gap-2 md:grid-cols-2">
             <select
               className="rounded border px-3 py-2 text-sm"
               value={selectedItemId}
               onChange={(e) => setSelectedItemId(Number(e.target.value))}
             >
-              <option value={0}>请选择兑换物品</option>
+              <option value={0}>{tx("请选择兑换物品", "Please select an item")}</option>
               {items.map((item) => (
                 <option key={item.id} value={item.id}>
-                  {item.name}
+                  {itemName(item.name)}
                 </option>
               ))}
             </select>
@@ -265,8 +323,8 @@ export default function MePage() {
               value={dayType}
               onChange={(e) => setDayType(e.target.value === "studyday" ? "studyday" : "holiday")}
             >
-              <option value="holiday">假期时间（按假期单价）</option>
-              <option value="studyday">学习日/非节假日（按学习日单价）</option>
+              <option value="holiday">{tx("假期时间（按假期单价）", "Holiday time (holiday price)")}</option>
+              <option value="studyday">{tx("学习日/非节假日（按学习日单价）", "Study day/non-holiday (study-day price)")}</option>
             </select>
 
             <input
@@ -276,19 +334,19 @@ export default function MePage() {
               max={24}
               value={quantity}
               onChange={(e) => setQuantity(Math.max(1, Number(e.target.value) || 1))}
-              placeholder="兑换时长（小时）"
+              placeholder={tx("兑换时长（小时）", "Redeem duration (hours)")}
             />
 
             <input
               className="rounded border px-3 py-2 text-sm"
               value={note}
               onChange={(e) => setNote(e.target.value)}
-              placeholder="备注（可选）"
+              placeholder={tx("备注（可选）", "Note (optional)")}
             />
           </div>
 
           <p className="mt-2 text-xs text-zinc-600">
-            当前单价：{unitCost} / 小时；预计扣分：{totalCost}
+            {tx("当前单价", "Current unit price")}: {unitCost} / {tx("小时", "hour")}；{tx("预计扣分", "Estimated cost")}: {totalCost}
           </p>
 
           <button
@@ -296,20 +354,20 @@ export default function MePage() {
             onClick={() => void redeem()}
             disabled={redeemLoading || !selectedItemId}
           >
-            {redeemLoading ? "兑换中..." : "确认兑换"}
+            {redeemLoading ? tx("兑换中...", "Redeeming...") : tx("确认兑换", "Confirm Redeem")}
           </button>
         </div>
       </section>
 
       <section className="mt-4 rounded-xl border bg-white p-4">
         <div className="flex items-center justify-between gap-2">
-          <h2 className="text-base font-semibold">兑换记录</h2>
+          <h2 className="text-base font-semibold">{tx("兑换记录", "Redeem Records")}</h2>
           <button
             className="rounded border px-3 py-1 text-xs hover:bg-zinc-100"
             onClick={() => void loadAll()}
             disabled={loading}
           >
-            刷新
+            {tx("刷新", "Refresh")}
           </button>
         </div>
 
@@ -317,15 +375,18 @@ export default function MePage() {
           {records.map((row) => (
             <article key={row.id} className="py-2 text-sm">
               <p>
-                #{row.id} · {row.item_name} · {row.quantity} 小时 · {row.day_type === "holiday" ? "假期" : "学习日"}
+                #{row.id} · {itemName(row.item_name)} · {row.quantity} {tx("小时", "hour")} ·{" "}
+                {row.day_type === "holiday" ? tx("假期", "Holiday") : tx("学习日", "Study Day")}
               </p>
               <p className="text-xs text-zinc-600">
-                单价 {row.unit_cost}，总扣分 {row.total_cost} · {fmtTs(row.created_at)}
+                {tx("单价", "Unit cost")} {row.unit_cost}，{tx("总扣分", "Total cost")} {row.total_cost} · {fmtTs(row.created_at)}
               </p>
-              {row.note && <p className="text-xs text-zinc-500">备注：{row.note}</p>}
+              {row.note && <p className="text-xs text-zinc-500">{tx("备注：", "Note: ")}{row.note}</p>}
             </article>
           ))}
-          {!loading && records.length === 0 && <p className="py-3 text-sm text-zinc-500">暂无兑换记录。</p>}
+          {!loading && records.length === 0 && (
+            <p className="py-3 text-sm text-zinc-500">{tx("暂无兑换记录。", "No redeem records yet.")}</p>
+          )}
         </div>
       </section>
     </main>

frontend/src/app/problems/page.tsx

@@ -4,6 +4,7 @@ import Link from "next/link";
 import { useCallback, useEffect, useMemo, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type Problem = {
   id: number;
@@ -33,7 +34,8 @@ type ProblemProfile = {
 
 type Preset = {
   key: string;
-  label: string;
+  labelZh: string;
+  labelEn: string;
   sourcePrefix?: string;
   tags?: string[];
 };
@@ -41,33 +43,39 @@ type Preset = {
 const PRESETS: Preset[] = [
   {
     key: "csp-beginner-default",
-    label: "CSP J/S 入门默认",
+    labelZh: "CSP J/S 入门默认",
+    labelEn: "CSP J/S Beginner Default",
     tags: ["csp-j", "csp-s", "noip-junior", "noip-senior"],
   },
   {
     key: "csp-j",
-    label: "仅 CSP-J / 普及",
+    labelZh: "仅 CSP-J / 普及",
+    labelEn: "CSP-J / Junior Only",
     tags: ["csp-j", "noip-junior"],
   },
   {
     key: "csp-s",
-    label: "仅 CSP-S / 提高",
+    labelZh: "仅 CSP-S / 提高",
+    labelEn: "CSP-S / Senior Only",
     tags: ["csp-s", "noip-senior"],
   },
   {
     key: "noip-junior",
-    label: "仅 NOIP 入门",
+    labelZh: "仅 NOIP 入门",
+    labelEn: "NOIP Junior Only",
     tags: ["noip-junior"],
   },
   {
     key: "luogu-all",
-    label: "洛谷导入全部",
+    labelZh: "洛谷导入全部",
+    labelEn: "All Luogu Imports",
     sourcePrefix: "luogu:",
     tags: [],
   },
   {
     key: "all",
-    label: "全站全部来源",
+    labelZh: "全站全部来源",
+    labelEn: "All Sources",
     tags: [],
   },
 ];
@@ -75,33 +83,39 @@ const PRESETS: Preset[] = [
 const QUICK_CARDS = [
   {
     presetKey: "csp-j",
-    title: "CSP-J 真题",
-    desc: "普及组入门训练",
+    titleZh: "CSP-J 真题",
+    titleEn: "CSP-J Problems",
+    descZh: "普及组入门训练",
+    descEn: "Junior training set",
   },
   {
     presetKey: "csp-s",
-    title: "CSP-S 真题",
-    desc: "提高组进阶训练",
+    titleZh: "CSP-S 真题",
+    titleEn: "CSP-S Problems",
+    descZh: "提高组进阶训练",
+    descEn: "Senior advanced set",
   },
   {
     presetKey: "noip-junior",
-    title: "NOIP 入门",
-    desc: "基础算法与思维",
+    titleZh: "NOIP 入门",
+    titleEn: "NOIP Junior",
+    descZh: "基础算法与思维",
+    descEn: "Basic algorithm thinking",
   },
 ] as const;
 
 const DIFFICULTY_OPTIONS = [
-  { value: "0", label: "全部难度" },
-  { value: "1", label: "1" },
-  { value: "2", label: "2" },
-  { value: "3", label: "3" },
-  { value: "4", label: "4" },
-  { value: "5", label: "5" },
-  { value: "6", label: "6" },
-  { value: "7", label: "7" },
-  { value: "8", label: "8" },
-  { value: "9", label: "9" },
-  { value: "10", label: "10" },
+  { value: "0", labelZh: "全部难度", labelEn: "All Levels" },
+  { value: "1", labelZh: "1", labelEn: "1" },
+  { value: "2", labelZh: "2", labelEn: "2" },
+  { value: "3", labelZh: "3", labelEn: "3" },
+  { value: "4", labelZh: "4", labelEn: "4" },
+  { value: "5", labelZh: "5", labelEn: "5" },
+  { value: "6", labelZh: "6", labelEn: "6" },
+  { value: "7", labelZh: "7", labelEn: "7" },
+  { value: "8", labelZh: "8", labelEn: "8" },
+  { value: "9", labelZh: "9", labelEn: "9" },
+  { value: "10", labelZh: "10", labelEn: "10" },
 ] as const;
 
 function parseProfile(raw: string): ProblemProfile | null {
@@ -145,6 +159,7 @@ function resolveTags(profile: ProblemProfile | null): string[] {
 }
 
 export default function ProblemsPage() {
+  const { isZh, tx } = useI18nText();
   const [presetKey, setPresetKey] = useState(PRESETS[0].key);
   const [keywordInput, setKeywordInput] = useState("");
   const [keyword, setKeyword] = useState("");
@@ -217,15 +232,25 @@ export default function ProblemsPage() {
   };
 
   return (
-    <main className="mx-auto max-w-7xl px-6 py-8">
+    <main className="mx-auto max-w-7xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
       <div className="flex flex-wrap items-end justify-between gap-3">
         <div>
-          <h1 className="text-2xl font-semibold">题库（CSP J/S 入门）</h1>
+          <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+            {tx("题库（CSP J/S 入门）", "Problem Set (CSP J/S Beginner)")}
+          </h1>
           <p className="mt-1 text-sm text-zinc-600">
-            参考洛谷题库列表交互，默认聚焦 CSP-J / CSP-S / NOIP 入门训练。
+            {tx(
+              "参考洛谷题库列表交互，默认聚焦 CSP-J / CSP-S / NOIP 入门训练。",
+              "Interaction style is inspired by Luogu problem list. Default focus: CSP-J / CSP-S / NOIP junior training."
+            )}
           </p>
         </div>
-        <p className="text-sm text-zinc-600">共 {totalCount} 题</p>
+        <div className="flex w-full flex-wrap items-center gap-3 text-sm sm:w-auto sm:justify-end">
+          <p className="text-zinc-600">{tx("共", "Total")} {totalCount} {tx("题", "problems")}</p>
+          <Link className="w-full rounded border px-3 py-1 text-center hover:bg-zinc-100 sm:w-auto" href="/backend-logs">
+            {tx("查看后台日志", "View Backend Logs")}
+          </Link>
+        </div>
       </div>
 
       <section className="mt-4 grid gap-3 md:grid-cols-3">
@@ -242,9 +267,9 @@ export default function ProblemsPage() {
               }`}
               onClick={() => selectPreset(card.presetKey)}
             >
-              <p className="text-base font-semibold">{card.title}</p>
+              <p className="text-base font-semibold">{isZh ? card.titleZh : card.titleEn}</p>
               <p className={`mt-1 text-xs ${active ? "text-zinc-200" : "text-zinc-500"}`}>
-                {card.desc}
+                {isZh ? card.descZh : card.descEn}
               </p>
             </button>
           );
@@ -261,14 +286,14 @@ export default function ProblemsPage() {
         >
           {PRESETS.map((item) => (
             <option key={item.key} value={item.key}>
-              {item.label}
+              {isZh ? item.labelZh : item.labelEn}
             </option>
           ))}
         </select>
 
         <input
           className="rounded border px-3 py-2 text-sm lg:col-span-2"
-          placeholder="搜索题号/标题/题面关键词"
+          placeholder={tx("搜索题号/标题/题面关键词", "Search id/title/statement keywords")}
           value={keywordInput}
           onChange={(e) => setKeywordInput(e.target.value)}
           onKeyDown={(e) => {
@@ -286,7 +311,7 @@ export default function ProblemsPage() {
         >
           {DIFFICULTY_OPTIONS.map((item) => (
             <option key={item.value} value={item.value}>
-              难度 {item.label}
+              {tx("难度", "Difficulty")} {isZh ? item.labelZh : item.labelEn}
             </option>
           ))}
         </select>
@@ -301,12 +326,12 @@ export default function ProblemsPage() {
             setPage(1);
           }}
         >
-          <option value="id:asc">题号升序</option>
-          <option value="id:desc">题号降序</option>
-          <option value="difficulty:asc">难度升序</option>
-          <option value="difficulty:desc">难度降序</option>
-          <option value="created_at:desc">最新导入</option>
-          <option value="title:asc">标题 A-Z</option>
+          <option value="id:asc">{tx("题号升序", "ID Asc")}</option>
+          <option value="id:desc">{tx("题号降序", "ID Desc")}</option>
+          <option value="difficulty:asc">{tx("难度升序", "Difficulty Asc")}</option>
+          <option value="difficulty:desc">{tx("难度降序", "Difficulty Desc")}</option>
+          <option value="created_at:desc">{tx("最新导入", "Newest Imported")}</option>
+          <option value="title:asc">{tx("标题 A-Z", "Title A-Z")}</option>
         </select>
 
         <button
@@ -314,88 +339,130 @@ export default function ProblemsPage() {
           onClick={applySearch}
           disabled={loading}
         >
-          {loading ? "加载中..." : "搜索"}
+          {loading ? tx("加载中...", "Loading...") : tx("搜索", "Search")}
         </button>
       </section>
 
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
-      <section className="mt-4 overflow-x-auto rounded-xl border bg-white">
-        <table className="min-w-full text-sm">
-          <thead className="bg-zinc-100 text-left text-zinc-700">
-            <tr>
-              <th className="px-3 py-2">题号</th>
-              <th className="px-3 py-2">标题</th>
-              <th className="px-3 py-2">通过/提交</th>
-              <th className="px-3 py-2">难度</th>
-              <th className="px-3 py-2">标签</th>
-              <th className="px-3 py-2">来源</th>
-            </tr>
-          </thead>
-          <tbody>
-            {rows.map(({ problem, profile }) => {
-              const pid = resolvePid(problem, profile);
-              const tags = resolveTags(profile);
-              return (
-                <tr key={problem.id} className="border-t hover:bg-zinc-50">
-                  <td className="px-3 py-2 font-medium text-blue-700">{pid}</td>
-                  <td className="px-3 py-2">
-                    <Link className="hover:underline" href={`/problems/${problem.id}`}>
-                      {problem.title}
-                    </Link>
-                  </td>
-                  <td className="px-3 py-2 text-zinc-600">{resolvePassRate(profile)}</td>
-                  <td className={`px-3 py-2 font-semibold ${difficultyClass(problem.difficulty)}`}>
-                    {problem.difficulty}
-                  </td>
-                  <td className="px-3 py-2">
-                    <div className="flex flex-wrap gap-1">
-                      {tags.length === 0 && <span className="text-zinc-400">-</span>}
-                      {tags.map((tag) => (
-                        <span key={tag} className="rounded bg-zinc-100 px-2 py-0.5 text-xs">
-                          {tag}
-                        </span>
-                      ))}
-                    </div>
-                  </td>
-                  <td className="px-3 py-2 text-zinc-500">{problem.source || "-"}</td>
-                </tr>
-              );
-            })}
-            {!loading && rows.length === 0 && (
+      <section className="mt-4 rounded-xl border bg-white">
+        <div className="divide-y md:hidden">
+          {rows.map(({ problem, profile }) => {
+            const pid = resolvePid(problem, profile);
+            const tags = resolveTags(profile);
+            return (
+              <article key={problem.id} className="space-y-2 p-3">
+                <div className="flex items-start justify-between gap-2">
+                  <Link className="font-medium text-blue-700 hover:underline" href={`/problems/${problem.id}`}>
+                    {pid} · {problem.title}
+                  </Link>
+                  <span className={`shrink-0 text-sm font-semibold ${difficultyClass(problem.difficulty)}`}>
+                    {tx("难度", "Difficulty")} {problem.difficulty}
+                  </span>
+                </div>
+                <p className="text-xs text-zinc-600">{tx("通过/提交：", "Accepted/Submissions: ")}{resolvePassRate(profile)}</p>
+                <p className="text-xs text-zinc-500 break-all">{tx("来源：", "Source: ")}{problem.source || "-"}</p>
+                <div className="flex flex-wrap gap-1">
+                  {tags.length === 0 && <span className="text-xs text-zinc-400">-</span>}
+                  {tags.map((tag) => (
+                    <span key={tag} className="rounded bg-zinc-100 px-2 py-0.5 text-xs">
+                      {tag}
+                    </span>
+                  ))}
+                </div>
+              </article>
+            );
+          })}
+          {!loading && rows.length === 0 && (
+            <p className="px-3 py-6 text-center text-sm text-zinc-500">
+              {tx(
+                "当前筛选下暂无题目，请切换题单预设或先执行导入脚本。",
+                "No problems under current filters. Switch preset or run import first."
+              )}
+            </p>
+          )}
+        </div>
+
+        <div className="hidden overflow-x-auto md:block">
+          <table className="min-w-full text-sm">
+            <thead className="bg-zinc-100 text-left text-zinc-700">
               <tr>
-                <td className="px-3 py-6 text-center text-zinc-500" colSpan={6}>
-                  当前筛选下暂无题目，请切换题单预设或先执行导入脚本。
-                </td>
+                <th className="px-3 py-2">{tx("题号", "ID")}</th>
+                <th className="px-3 py-2">{tx("标题", "Title")}</th>
+                <th className="px-3 py-2">{tx("通过/提交", "Accepted/Submissions")}</th>
+                <th className="px-3 py-2">{tx("难度", "Difficulty")}</th>
+                <th className="px-3 py-2">{tx("标签", "Tags")}</th>
+                <th className="px-3 py-2">{tx("来源", "Source")}</th>
               </tr>
-            )}
-          </tbody>
-        </table>
+            </thead>
+            <tbody>
+              {rows.map(({ problem, profile }) => {
+                const pid = resolvePid(problem, profile);
+                const tags = resolveTags(profile);
+                return (
+                  <tr key={problem.id} className="border-t hover:bg-zinc-50">
+                    <td className="px-3 py-2 font-medium text-blue-700">{pid}</td>
+                    <td className="px-3 py-2">
+                      <Link className="hover:underline" href={`/problems/${problem.id}`}>
+                        {problem.title}
+                      </Link>
+                    </td>
+                    <td className="px-3 py-2 text-zinc-600">{resolvePassRate(profile)}</td>
+                    <td className={`px-3 py-2 font-semibold ${difficultyClass(problem.difficulty)}`}>
+                      {problem.difficulty}
+                    </td>
+                    <td className="px-3 py-2">
+                      <div className="flex flex-wrap gap-1">
+                        {tags.length === 0 && <span className="text-zinc-400">-</span>}
+                        {tags.map((tag) => (
+                          <span key={tag} className="rounded bg-zinc-100 px-2 py-0.5 text-xs">
+                            {tag}
+                          </span>
+                        ))}
+                      </div>
+                    </td>
+                    <td className="px-3 py-2 text-zinc-500">{problem.source || "-"}</td>
+                  </tr>
+                );
+              })}
+              {!loading && rows.length === 0 && (
+                <tr>
+                  <td className="px-3 py-6 text-center text-zinc-500" colSpan={6}>
+                    {tx(
+                      "当前筛选下暂无题目，请切换题单预设或先执行导入脚本。",
+                      "No problems under current filters. Switch preset or run import first."
+                    )}
+                  </td>
+                </tr>
+              )}
+            </tbody>
+          </table>
+        </div>
       </section>
 
-      <div className="mt-4 flex flex-wrap items-center justify-between gap-3 text-sm">
-        <div className="flex items-center gap-2">
+      <div className="mt-4 flex flex-col gap-3 text-sm sm:flex-row sm:items-center sm:justify-between">
+        <div className="flex flex-wrap items-center gap-2">
           <button
             className="rounded border px-3 py-1 disabled:opacity-50"
             onClick={() => setPage((p) => Math.max(1, p - 1))}
             disabled={loading || page <= 1}
           >
-            上一页
+            {tx("上一页", "Prev")}
           </button>
           <span>
-            第 {page} / {totalPages} 页
+            {isZh ? `第 ${page} / ${totalPages} 页` : `Page ${page} / ${totalPages}`}
           </span>
           <button
             className="rounded border px-3 py-1 disabled:opacity-50"
             onClick={() => setPage((p) => Math.min(totalPages, p + 1))}
             disabled={loading || page >= totalPages}
           >
-            下一页
+            {tx("下一页", "Next")}
           </button>
         </div>
 
-        <div className="flex items-center gap-2">
-          <span>每页</span>
+        <div className="flex items-center gap-2 sm:justify-end">
+          <span>{tx("每页", "Per Page")}</span>
           <select
             className="rounded border px-2 py-1"
             value={pageSize}

frontend/src/app/run/page.tsx

@@ -3,6 +3,7 @@
 import { useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type RunResult = {
   status: string;
@@ -23,6 +24,7 @@ int main() {
 `;
 
 export default function RunPage() {
+  const { tx } = useI18nText();
   const [code, setCode] = useState(starterCode);
   const [input, setInput] = useState("hello csp");
   const [loading, setLoading] = useState(false);
@@ -47,21 +49,23 @@ export default function RunPage() {
   };
 
   return (
-    <main className="mx-auto max-w-6xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">在线 C++ 编写 / 编译 / 运行</h1>
+    <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("在线 C++ 编写 / 编译 / 运行", "Online C++ Editor / Compile / Run")}
+      </h1>
 
       <div className="mt-4 grid gap-4 lg:grid-cols-2">
         <section className="rounded-xl border bg-white p-4">
-          <h2 className="text-sm font-medium">代码</h2>
+          <h2 className="text-sm font-medium">{tx("代码", "Code")}</h2>
           <textarea
-            className="mt-2 h-[420px] w-full rounded border p-3 font-mono text-sm"
+            className="mt-2 h-72 w-full rounded border p-3 font-mono text-sm sm:h-[420px]"
             value={code}
             onChange={(e) => setCode(e.target.value)}
           />
         </section>
 
         <section className="rounded-xl border bg-white p-4">
-          <h2 className="text-sm font-medium">标准输入</h2>
+          <h2 className="text-sm font-medium">{tx("标准输入", "Standard Input")}</h2>
           <textarea
             className="mt-2 h-32 w-full rounded border p-3 font-mono text-sm"
             value={input}
@@ -69,11 +73,11 @@ export default function RunPage() {
           />
 
           <button
-            className="mt-3 rounded bg-zinc-900 px-4 py-2 text-white disabled:opacity-50"
+            className="mt-3 w-full rounded bg-zinc-900 px-4 py-2 text-white disabled:opacity-50 sm:w-auto"
             onClick={() => void run()}
             disabled={loading}
           >
-            {loading ? "运行中..." : "运行"}
+            {loading ? tx("运行中...", "Running...") : tx("运行", "Run")}
           </button>
 
           {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
@@ -81,7 +85,7 @@ export default function RunPage() {
           {result && (
             <div className="mt-4 space-y-3 text-sm">
               <p>
-                状态: <b>{result.status}</b> · 耗时: {result.time_ms}ms
+                {tx("状态", "Status")}: <b>{result.status}</b> · {tx("耗时", "Time")}: {result.time_ms}ms
               </p>
               <div>
                 <h3 className="font-medium">stdout</h3>

frontend/src/app/submissions/[id]/page.tsx

@@ -3,7 +3,19 @@
 import { useParams } from "next/navigation";
 import { useEffect, useMemo, useState } from "react";
 
+import { MarkdownRenderer } from "@/components/markdown-renderer";
 import { apiFetch } from "@/lib/api";
+import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
+
+type SubmissionAnalysis = {
+  feedback_md: string;
+  links: Array<{ title: string; url: string }>;
+  model_name: string;
+  status: string;
+  created_at: number;
+  updated_at: number;
+};
 
 type Submission = {
   id: number;
@@ -14,72 +26,184 @@ type Submission = {
   code: string;
   status: string;
   score: number;
+  rating_delta: number;
   time_ms: number;
   memory_kb: number;
   compile_log: string;
   runtime_log: string;
   created_at: number;
+  has_viewed_answer: boolean;
+  answer_view_count: number;
+  answer_view_total_cost: number;
+  last_answer_view_at: number | null;
+  analysis: SubmissionAnalysis | null;
 };
 
+function fmtTs(v: number | null): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
+function fmtRatingDelta(delta: number): string {
+  if (delta > 0) return `+${delta}`;
+  return `${delta}`;
+}
+
 export default function SubmissionDetailPage() {
+  const { tx } = useI18nText();
   const params = useParams<{ id: string }>();
   const id = useMemo(() => Number(params.id), [params.id]);
 
   const [data, setData] = useState<Submission | null>(null);
   const [error, setError] = useState("");
   const [loading, setLoading] = useState(false);
+  const [analysisLoading, setAnalysisLoading] = useState(false);
+  const [analysisMsg, setAnalysisMsg] = useState("");
+
+  const load = async () => {
+    setLoading(true);
+    setError("");
+    try {
+      const d = await apiFetch<Submission>(`/api/v1/submissions/${id}`);
+      setData(d);
+    } catch (e: unknown) {
+      setError(String(e));
+    } finally {
+      setLoading(false);
+    }
+  };
 
   useEffect(() => {
-    const load = async () => {
-      setLoading(true);
-      setError("");
-      try {
-        const d = await apiFetch<Submission>(`/api/v1/submissions/${id}`);
-        setData(d);
-      } catch (e: unknown) {
-        setError(String(e));
-      } finally {
-        setLoading(false);
-      }
-    };
-    if (Number.isFinite(id) && id > 0) void load();
+    if (Number.isFinite(id) && id > 0) {
+      void load();
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [id]);
 
+  const generateAnalysis = async (refresh = false) => {
+    setAnalysisLoading(true);
+    setAnalysisMsg("");
+    setError("");
+    try {
+      const token = readToken();
+      if (!token) throw new Error(tx("请先登录后再生成评测建议", "Please sign in before generating analysis"));
+      const result = await apiFetch<SubmissionAnalysis>(
+        `/api/v1/submissions/${id}/analysis`,
+        {
+          method: "POST",
+          body: JSON.stringify({ refresh }),
+        },
+        token
+      );
+      setData((prev) => (prev ? { ...prev, analysis: result } : prev));
+      setAnalysisMsg(refresh ? tx("已重新生成评测建议", "Analysis regenerated") : tx("评测建议已生成", "Analysis generated"));
+    } catch (e: unknown) {
+      setAnalysisMsg(`${tx("生成失败：", "Generate failed: ")}${String(e)}`);
+    } finally {
+      setAnalysisLoading(false);
+    }
+  };
+
   return (
-    <main className="mx-auto max-w-5xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">提交详情 #{id}</h1>
-      {loading && <p className="mt-4 text-sm text-zinc-500">加载中...</p>}
+    <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("提交详情", "Submission Detail")} #{id}
+      </h1>
+      {loading && <p className="mt-4 text-sm text-zinc-500">{tx("加载中...", "Loading...")}</p>}
       {error && <p className="mt-4 text-sm text-red-600">{error}</p>}
 
       {data && (
         <div className="mt-4 space-y-4">
-          <div className="rounded-xl border bg-white p-4 text-sm">
-            <p>用户: {data.user_id}</p>
-            <p>题目: {data.problem_id}</p>
-            <p>比赛: {data.contest_id ?? "-"}</p>
-            <p>语言: {data.language}</p>
-            <p>状态: {data.status}</p>
-            <p>分数: {data.score}</p>
-            <p>时间: {data.time_ms} ms</p>
-            <p>内存: {data.memory_kb} KB</p>
-          </div>
+          <section className="rounded-xl border bg-white p-4 text-sm">
+            <div className="grid gap-1 sm:grid-cols-2">
+              <p>{tx("用户", "User")}: {data.user_id}</p>
+              <p>{tx("题目", "Problem")}: {data.problem_id}</p>
+              <p>{tx("比赛", "Contest")}: {data.contest_id ?? "-"}</p>
+              <p>{tx("语言", "Language")}: {data.language}</p>
+              <p>{tx("状态", "Status")}: {data.status}</p>
+              <p>{tx("分数", "Score")}: {data.score}</p>
+              <p>{tx("Rating 变化", "Rating Delta")}: {fmtRatingDelta(data.rating_delta)}</p>
+              <p>{tx("时间", "Time")}: {data.time_ms} ms</p>
+              <p>{tx("内存", "Memory")}: {data.memory_kb} KB</p>
+              <p>{tx("提交时间", "Submitted At")}: {fmtTs(data.created_at)}</p>
+              <p>{tx("查看答案", "Viewed Answer")}: {data.has_viewed_answer ? tx("已查看", "Yes") : tx("未查看", "No")}</p>
+              <p>{tx("查看次数", "View Count")}: {data.answer_view_count}</p>
+              <p>{tx("查看扣分", "View Cost")}: {data.answer_view_total_cost}</p>
+              <p>{tx("最后查看答案", "Last View Time")}: {fmtTs(data.last_answer_view_at)}</p>
+            </div>
+          </section>
 
           <section className="rounded-xl border bg-white p-4">
-            <h2 className="text-sm font-medium">代码</h2>
+            <div className="flex flex-wrap items-center gap-2">
+              <h2 className="text-sm font-medium">{tx("LLM 评测建议（福建 CSP-J/S 规范）", "LLM Analysis (Fujian CSP-J/S style)")}</h2>
+              <button
+                className="rounded border px-3 py-1 text-xs disabled:opacity-50"
+                onClick={() => void generateAnalysis(false)}
+                disabled={analysisLoading}
+              >
+                {analysisLoading ? tx("生成中...", "Generating...") : tx("生成评测建议", "Generate Analysis")}
+              </button>
+              <button
+                className="rounded border px-3 py-1 text-xs disabled:opacity-50"
+                onClick={() => void generateAnalysis(true)}
+                disabled={analysisLoading}
+              >
+                {tx("重新生成", "Regenerate")}
+              </button>
+            </div>
+            {analysisMsg && <p className="mt-2 text-xs text-zinc-600">{analysisMsg}</p>}
+            {data.analysis ? (
+              <div className="mt-3 space-y-3">
+                <div className="rounded border bg-zinc-50 p-3 text-xs text-zinc-600">
+                  <p>{tx("模型", "Model")}: {data.analysis.model_name || "-"}</p>
+                  <p>{tx("状态", "Status")}: {data.analysis.status || "ready"}</p>
+                  <p>{tx("更新时间", "Updated At")}: {fmtTs(data.analysis.updated_at)}</p>
+                </div>
+                <div className="rounded border bg-white p-3">
+                  <MarkdownRenderer markdown={data.analysis.feedback_md} />
+                </div>
+                {(data.analysis.links ?? []).length > 0 && (
+                  <div className="rounded border bg-zinc-50 p-3">
+                    <p className="text-xs font-medium text-zinc-700">{tx("推荐外链资料", "Recommended Links")}</p>
+                    <div className="mt-2 flex flex-wrap gap-2">
+                      {data.analysis.links.map((item) => (
+                        <a
+                          key={`${item.title}-${item.url}`}
+                          className="rounded border px-2 py-1 text-xs text-blue-700 hover:underline"
+                          href={item.url}
+                          target="_blank"
+                          rel="noreferrer"
+                        >
+                          {item.title}
+                        </a>
+                      ))}
+                    </div>
+                  </div>
+                )}
+              </div>
+            ) : (
+              <p className="mt-2 text-xs text-zinc-500">
+                {tx("暂无评测建议，可点击上方按钮生成。", "No analysis yet. Click the button above to generate one.")}
+              </p>
+            )}
+          </section>
+
+          <section className="rounded-xl border bg-white p-4">
+            <h2 className="text-sm font-medium">{tx("提交代码", "Submitted Code")}</h2>
             <pre className="mt-2 overflow-auto rounded bg-zinc-900 p-3 text-xs text-zinc-100">
-              {data.code}
+              {data.code || "(empty)"}
             </pre>
           </section>
 
           <section className="rounded-xl border bg-white p-4">
-            <h2 className="text-sm font-medium">编译日志</h2>
+            <h2 className="text-sm font-medium">{tx("编译日志", "Compile Log")}</h2>
             <pre className="mt-2 overflow-auto rounded bg-zinc-900 p-3 text-xs text-zinc-100">
               {data.compile_log || "(empty)"}
             </pre>
           </section>
 
           <section className="rounded-xl border bg-white p-4">
-            <h2 className="text-sm font-medium">运行日志</h2>
+            <h2 className="text-sm font-medium">{tx("运行日志", "Runtime Log")}</h2>
             <pre className="mt-2 overflow-auto rounded bg-zinc-900 p-3 text-xs text-zinc-100">
               {data.runtime_log || "(empty)"}
             </pre>

frontend/src/app/submissions/page.tsx

@@ -4,6 +4,7 @@ import Link from "next/link";
 import { useEffect, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
+import { useI18nText } from "@/lib/i18n";
 
 type Submission = {
   id: number;
@@ -12,6 +13,7 @@ type Submission = {
   contest_id: number | null;
   status: string;
   score: number;
+  rating_delta: number;
   time_ms: number;
   created_at: number;
 };
@@ -19,6 +21,7 @@ type Submission = {
 type ListResp = { items: Submission[]; page: number; page_size: number };
 
 export default function SubmissionsPage() {
+  const { tx } = useI18nText();
   const [userId, setUserId] = useState("");
   const [problemId, setProblemId] = useState("");
   const [contestId, setContestId] = useState("");
@@ -26,6 +29,17 @@ export default function SubmissionsPage() {
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState("");
 
+  const fmtRatingDelta = (delta: number) => {
+    if (delta > 0) return `+${delta}`;
+    return `${delta}`;
+  };
+
+  const ratingDeltaClass = (delta: number) => {
+    if (delta > 0) return "text-emerald-700";
+    if (delta < 0) return "text-red-700";
+    return "text-zinc-600";
+  };
+
   const load = async () => {
     setLoading(true);
     setError("");
@@ -49,8 +63,10 @@ export default function SubmissionsPage() {
   }, []);
 
   return (
-    <main className="mx-auto max-w-6xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">提交记录</h1>
+    <main className="mx-auto max-w-6xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("提交记录", "Submissions")}
+      </h1>
 
       <div className="mt-4 grid gap-3 rounded-xl border bg-white p-4 md:grid-cols-4">
         <input
@@ -76,43 +92,80 @@ export default function SubmissionsPage() {
           onClick={() => void load()}
           disabled={loading}
         >
-          {loading ? "加载中..." : "筛选"}
+          {loading ? tx("加载中...", "Loading...") : tx("筛选", "Filter")}
         </button>
       </div>
 
       {error && <p className="mt-3 text-sm text-red-600">{error}</p>}
 
-      <div className="mt-4 overflow-x-auto rounded-xl border bg-white">
-        <table className="min-w-full text-sm">
-          <thead className="bg-zinc-100 text-left">
-            <tr>
-              <th className="px-3 py-2">ID</th>
-              <th className="px-3 py-2">用户</th>
-              <th className="px-3 py-2">题目</th>
-              <th className="px-3 py-2">状态</th>
-              <th className="px-3 py-2">分数</th>
-              <th className="px-3 py-2">耗时(ms)</th>
-              <th className="px-3 py-2">详情</th>
-            </tr>
-          </thead>
-          <tbody>
-            {items.map((s) => (
-              <tr key={s.id} className="border-t">
-                <td className="px-3 py-2">{s.id}</td>
-                <td className="px-3 py-2">{s.user_id}</td>
-                <td className="px-3 py-2">{s.problem_id}</td>
-                <td className="px-3 py-2">{s.status}</td>
-                <td className="px-3 py-2">{s.score}</td>
-                <td className="px-3 py-2">{s.time_ms}</td>
-                <td className="px-3 py-2">
-                  <Link className="text-blue-600 underline" href={`/submissions/${s.id}`}>
-                    查看
-                  </Link>
-                </td>
+      <div className="mt-4 rounded-xl border bg-white">
+        <div className="divide-y md:hidden">
+          {items.map((s) => (
+            <article key={s.id} className="space-y-2 p-3 text-sm">
+              <div className="flex items-center justify-between gap-3">
+                <p className="font-medium">{tx("提交", "Submission")} #{s.id}</p>
+                <span className="text-xs text-zinc-500">{s.status}</span>
+              </div>
+              <p className="text-xs text-zinc-600">
+                {tx("用户", "User")} {s.user_id} · {tx("题目", "Problem")} {s.problem_id} · {tx("分数", "Score")} {s.score}
+              </p>
+              <p className={`text-xs ${ratingDeltaClass(s.rating_delta)}`}>
+                {tx("Rating 变化", "Rating Delta")} {fmtRatingDelta(s.rating_delta)}
+              </p>
+              <p className="text-xs text-zinc-600">{tx("耗时", "Time")} {s.time_ms} ms</p>
+              <Link className="text-blue-600 underline" href={`/submissions/${s.id}`}>
+                {tx("查看详情", "View Detail")}
+              </Link>
+            </article>
+          ))}
+          {!loading && items.length === 0 && (
+            <p className="px-3 py-5 text-center text-sm text-zinc-500">{tx("暂无提交记录", "No submissions yet")}</p>
+          )}
+        </div>
+
+        <div className="hidden overflow-x-auto md:block">
+          <table className="min-w-full text-sm">
+            <thead className="bg-zinc-100 text-left">
+              <tr>
+                <th className="px-3 py-2">ID</th>
+                <th className="px-3 py-2">{tx("用户", "User")}</th>
+                <th className="px-3 py-2">{tx("题目", "Problem")}</th>
+                <th className="px-3 py-2">{tx("状态", "Status")}</th>
+                <th className="px-3 py-2">{tx("分数", "Score")}</th>
+                <th className="px-3 py-2">{tx("Rating 变化", "Rating Delta")}</th>
+                <th className="px-3 py-2">{tx("耗时(ms)", "Time(ms)")}</th>
+                <th className="px-3 py-2">{tx("详情", "Detail")}</th>
               </tr>
-            ))}
-          </tbody>
-        </table>
+            </thead>
+            <tbody>
+              {items.map((s) => (
+                <tr key={s.id} className="border-t">
+                  <td className="px-3 py-2">{s.id}</td>
+                  <td className="px-3 py-2">{s.user_id}</td>
+                  <td className="px-3 py-2">{s.problem_id}</td>
+                  <td className="px-3 py-2">{s.status}</td>
+                  <td className="px-3 py-2">{s.score}</td>
+                  <td className={`px-3 py-2 ${ratingDeltaClass(s.rating_delta)}`}>
+                    {fmtRatingDelta(s.rating_delta)}
+                  </td>
+                  <td className="px-3 py-2">{s.time_ms}</td>
+                  <td className="px-3 py-2">
+                    <Link className="text-blue-600 underline" href={`/submissions/${s.id}`}>
+                      {tx("查看", "View")}
+                    </Link>
+                  </td>
+                </tr>
+              ))}
+              {!loading && items.length === 0 && (
+                <tr>
+                  <td className="px-3 py-5 text-center text-zinc-500" colSpan={8}>
+                    {tx("暂无提交记录", "No submissions yet")}
+                  </td>
+                </tr>
+              )}
+            </tbody>
+          </table>
+        </div>
       </div>
     </main>
   );

frontend/src/app/wrong-book/page.tsx

@@ -1,9 +1,11 @@
 "use client";
 
+import Link from "next/link";
 import { useEffect, useState } from "react";
 
 import { apiFetch } from "@/lib/api";
 import { readToken } from "@/lib/auth";
+import { useI18nText } from "@/lib/i18n";
 
 type WrongBookItem = {
   user_id: number;
@@ -14,7 +16,13 @@ type WrongBookItem = {
   updated_at: number;
 };
 
+function fmtTs(v: number): string {
+  if (!v) return "-";
+  return new Date(v * 1000).toLocaleString();
+}
+
 export default function WrongBookPage() {
+  const { tx } = useI18nText();
   const [token, setToken] = useState("");
   const [items, setItems] = useState<WrongBookItem[]>([]);
   const [loading, setLoading] = useState(false);
@@ -28,7 +36,7 @@ export default function WrongBookPage() {
     setLoading(true);
     setError("");
     try {
-      if (!token) throw new Error("请先登录");
+      if (!token) throw new Error(tx("请先登录", "Please sign in first"));
       const data = await apiFetch<WrongBookItem[]>("/api/v1/me/wrong-book", {}, token);
       setItems(data);
     } catch (e: unknown) {
@@ -65,9 +73,13 @@ export default function WrongBookPage() {
   };
 
   return (
-    <main className="mx-auto max-w-5xl px-6 py-8">
-      <h1 className="text-2xl font-semibold">错题本</h1>
-      <p className="mt-2 text-sm text-zinc-600">未通过提交会自动进入错题本。</p>
+    <main className="mx-auto max-w-5xl px-3 py-6 max-[390px]:px-2 sm:px-4 md:px-6 md:py-8">
+      <h1 className="text-xl font-semibold max-[390px]:text-lg sm:text-2xl">
+        {tx("错题本", "Wrong Book")}
+      </h1>
+      <p className="mt-2 text-sm text-zinc-600">
+        {tx("未通过提交会自动进入错题本。", "Failed submissions are added to the wrong-book automatically.")}
+      </p>
 
       <div className="mt-4">
         <button
@@ -75,7 +87,7 @@ export default function WrongBookPage() {
           onClick={() => void load()}
           disabled={loading}
         >
-          {loading ? "刷新中..." : "刷新"}
+          {loading ? tx("刷新中...", "Refreshing...") : tx("刷新", "Refresh")}
         </button>
       </div>
 
@@ -84,22 +96,42 @@ export default function WrongBookPage() {
       <div className="mt-4 space-y-3">
         {items.map((item) => (
           <div key={item.problem_id} className="rounded-xl border bg-white p-4">
-            <div className="flex items-center justify-between gap-2">
-              <p className="font-medium">
+            <div className="flex flex-wrap items-start justify-between gap-2">
+              <Link className="font-medium text-blue-700 hover:underline" href={`/problems/${item.problem_id}`}>
                 #{item.problem_id} {item.problem_title}
-              </p>
+              </Link>
+              <div className="flex flex-wrap items-center gap-2">
+                <Link
+                  className="rounded border px-3 py-1 text-sm hover:bg-zinc-100"
+                  href={`/problems/${item.problem_id}`}
+                >
+                  {tx("查看题目", "View Problem")}
+                </Link>
+                {item.last_submission_id && (
+                  <Link
+                    className="rounded border px-3 py-1 text-sm hover:bg-zinc-100"
+                    href={`/submissions/${item.last_submission_id}`}
+                  >
+                    {tx("查看最近提交", "View Latest Submission")}
+                  </Link>
+                )}
+              </div>
+            </div>
+
+            <p className="mt-1 text-xs text-zinc-500">
+              {tx("最近提交:", "Latest Submission:")} {item.last_submission_id ?? "-"} ·{" "}
+              {tx("更新时间:", "Updated:")} {fmtTs(item.updated_at)}
+            </p>
+
+            <div className="mt-2 flex flex-wrap justify-end gap-2">
               <button
                 className="rounded border px-3 py-1 text-sm hover:bg-zinc-100"
                 onClick={() => void removeItem(item.problem_id)}
               >
-                移除
+                {tx("移除", "Remove")}
               </button>
             </div>
 
-            <p className="mt-1 text-xs text-zinc-500">
-              最近提交: {item.last_submission_id ?? "-"}
-            </p>
-
             <textarea
               className="mt-2 h-24 w-full rounded border p-2 text-sm"
               value={item.note}
@@ -116,10 +148,18 @@ export default function WrongBookPage() {
               className="mt-2 rounded border px-3 py-1 text-sm hover:bg-zinc-100"
               onClick={() => void updateNote(item.problem_id, item.note)}
             >
-              保存备注
+              {tx("保存备注", "Save Note")}
             </button>
           </div>
         ))}
+        {!loading && items.length === 0 && (
+          <div className="rounded-xl border bg-white p-6 text-center text-sm text-zinc-500">
+            {tx(
+              "暂无错题。提交未通过后会自动加入错题本，可点击“查看题目/查看最近提交”快速复盘。",
+              "No wrong-book entries yet. Failed submissions will be added automatically; use “View Problem/View Latest Submission” to review quickly."
+            )}
+          </div>
+        )}
       </div>
     </main>
   );

frontend/src/components/app-nav.tsx

@@ -1,64 +1,321 @@
 "use client";
 
-import Link from "next/link";
-import { useEffect, useState } from "react";
+import { usePathname, useRouter } from "next/navigation";
+import { useEffect, useMemo, useRef, useState } from "react";
 
+import { useUiPreferences } from "@/components/ui-preference-provider";
+import { apiFetch } from "@/lib/api";
 import { clearToken, readToken } from "@/lib/auth";
+import type { ThemeId } from "@/themes/types";
 
-const links = [
-  ["首页", "/"],
-  ["登录", "/auth"],
-  ["题库", "/problems"],
-  ["提交", "/submissions"],
-  ["错题本", "/wrong-book"],
-  ["比赛", "/contests"],
-  ["知识库", "/kb"],
-  ["导入任务", "/imports"],
-  ["在线运行", "/run"],
-  ["我的", "/me"],
-  ["排行榜", "/leaderboard"],
-  ["API文档", "/api-docs"],
-] as const;
+type NavLink = {
+  label: string;
+  href: string;
+};
+
+type NavGroup = {
+  key: string;
+  label: string;
+  links: NavLink[];
+};
+
+function buildNavGroups(t: (key: string) => string, isAdmin: boolean): NavGroup[] {
+  const groups: NavGroup[] = [
+    {
+      key: "learn",
+      label: t("nav.group.learn"),
+      links: [
+        { label: t("nav.link.home"), href: "/" },
+        { label: t("nav.link.problems"), href: "/problems" },
+        { label: t("nav.link.submissions"), href: "/submissions" },
+        { label: t("nav.link.wrong_book"), href: "/wrong-book" },
+        { label: t("nav.link.kb"), href: "/kb" },
+        { label: t("nav.link.run"), href: "/run" },
+      ],
+    },
+    {
+      key: "contest",
+      label: t("nav.group.contest"),
+      links: [
+        { label: t("nav.link.contests"), href: "/contests" },
+        { label: t("nav.link.leaderboard"), href: "/leaderboard" },
+      ],
+    },
+    {
+      key: "account",
+      label: t("nav.group.account"),
+      links: [
+        { label: t("nav.link.auth"), href: "/auth" },
+        { label: t("nav.link.me"), href: "/me" },
+      ],
+    },
+  ];
+
+  if (isAdmin) {
+    groups.splice(2, 0, {
+      key: "system",
+      label: t("nav.group.system"),
+      links: [
+        { label: t("nav.link.imports"), href: "/imports" },
+        { label: t("nav.link.backend_logs"), href: "/backend-logs" },
+        { label: t("nav.link.admin_users"), href: "/admin-users" },
+        { label: t("nav.link.admin_redeem"), href: "/admin-redeem" },
+        { label: t("nav.link.api_docs"), href: "/api-docs" },
+      ],
+    });
+  }
+
+  return groups;
+}
+
+function isActivePath(pathname: string, href: string): boolean {
+  if (pathname === href) return true;
+  if (href === "/") return pathname === "/";
+  return pathname.startsWith(`${href}/`);
+}
+
+function resolveActiveGroup(pathname: string, groups: NavGroup[]): string {
+  for (const group of groups) {
+    for (const item of group.links) {
+      if (isActivePath(pathname, item.href)) return group.key;
+    }
+  }
+  return groups[0]?.key ?? "learn";
+}
+
+function resolveActiveLink(pathname: string, group: NavGroup): string {
+  for (const item of group.links) {
+    if (isActivePath(pathname, item.href)) return item.href;
+  }
+  return group.links[0]?.href ?? "/";
+}
 
 export function AppNav() {
+  const pathname = usePathname();
+  const router = useRouter();
+  const { theme, setTheme, language, setLanguage, themes, t } = useUiPreferences();
+
   const [hasToken, setHasToken] = useState<boolean>(() => Boolean(readToken()));
+  const [isAdmin, setIsAdmin] = useState(false);
+  const [menuOpen, setMenuOpen] = useState(false);
+  const [desktopOpenGroup, setDesktopOpenGroup] = useState<string | null>(null);
+  const desktopMenuRef = useRef<HTMLDivElement | null>(null);
+  const navGroups = useMemo(() => buildNavGroups(t, isAdmin), [isAdmin, t]);
+  const activeGroup = resolveActiveGroup(pathname, navGroups);
+  const usePopupSecondary = theme === "default";
 
   useEffect(() => {
-    const refresh = () => setHasToken(Boolean(readToken()));
-    window.addEventListener("storage", refresh);
-    window.addEventListener("focus", refresh);
-    return () => {
-      window.removeEventListener("storage", refresh);
-      window.removeEventListener("focus", refresh);
+    let canceled = false;
+    const refresh = async () => {
+      const token = readToken();
+      if (canceled) return;
+      setHasToken(Boolean(token));
+      if (!token) {
+        setIsAdmin(false);
+        return;
+      }
+      try {
+        const me = await apiFetch<{ username?: string }>("/api/v1/me", {}, token);
+        if (!canceled) {
+          setIsAdmin((me?.username ?? "") === "admin");
+        }
+      } catch {
+        if (!canceled) setIsAdmin(false);
+      }
     };
-  }, []);
+    const onRefresh = () => {
+      void refresh();
+    };
+    void refresh();
+    window.addEventListener("storage", onRefresh);
+    window.addEventListener("focus", onRefresh);
+    return () => {
+      canceled = true;
+      window.removeEventListener("storage", onRefresh);
+      window.removeEventListener("focus", onRefresh);
+    };
+  }, [pathname]);
+
+  useEffect(() => {
+    if (!usePopupSecondary || !desktopOpenGroup) return;
+    const onMouseDown = (event: MouseEvent) => {
+      const target = event.target as Node | null;
+      if (!target) return;
+      if (desktopMenuRef.current?.contains(target)) return;
+      setDesktopOpenGroup(null);
+    };
+    window.addEventListener("mousedown", onMouseDown);
+    return () => window.removeEventListener("mousedown", onMouseDown);
+  }, [desktopOpenGroup, usePopupSecondary]);
+
+  const currentGroup = navGroups.find((g) => g.key === activeGroup) ?? navGroups[0];
 
   return (
-    <header className="border-b bg-white">
-      <div className="mx-auto flex max-w-6xl flex-wrap items-center gap-2 px-4 py-3">
-        {links.map(([label, href]) => (
-          <Link
-            key={href}
-            href={href}
-            className="rounded-md border px-3 py-1 text-sm hover:bg-zinc-100"
+    <header className="print-hidden border-b bg-[color:var(--surface)]/95 backdrop-blur supports-[backdrop-filter]:bg-[color:var(--surface)]/85">
+      <div className="mx-auto max-w-6xl px-3 py-3 max-[390px]:px-2 max-[390px]:py-2 sm:px-4">
+        <div className="flex items-center justify-between md:hidden">
+          <span className="text-sm font-medium text-zinc-700">{t("nav.menu")}</span>
+          <button
+            type="button"
+            className="rounded-md border px-3 py-1 text-sm hover:bg-zinc-100 max-[390px]:px-2 max-[390px]:text-xs"
+            onClick={() => setMenuOpen((v) => !v)}
+            aria-expanded={menuOpen}
+            aria-controls="main-nav-links"
           >
-            {label}
-          </Link>
-        ))}
+            {menuOpen ? t("nav.collapse") : t("nav.expand")}
+          </button>
+        </div>
 
-        <div className="ml-auto flex items-center gap-2 text-sm">
+        <div id="main-nav-links" className={`${menuOpen ? "mt-3 block" : "hidden"} md:mt-0 md:block`}>
+          <div className="space-y-3">
+            {usePopupSecondary ? (
+              <div ref={desktopMenuRef} className="hidden flex-wrap items-center gap-2 md:flex">
+                {navGroups.map((group) => {
+                  const active = activeGroup === group.key;
+                  const opened = desktopOpenGroup === group.key;
+                  return (
+                    <div key={group.key} className="relative">
+                      <button
+                        type="button"
+                        className={`rounded-md border px-3 py-1 text-sm ${
+                          active ? "border-zinc-900 bg-zinc-900 text-white" : "hover:bg-zinc-100"
+                        }`}
+                        aria-expanded={opened}
+                        onClick={() =>
+                          setDesktopOpenGroup((prev) => (prev === group.key ? null : group.key))
+                        }
+                      >
+                        {group.label}
+                      </button>
+                      {opened && (
+                        <div className="absolute left-0 top-full z-50 mt-2 min-w-[11rem] rounded-md border bg-[color:var(--surface)] p-1 shadow-lg">
+                          {group.links.map((item) => {
+                            const linkActive = isActivePath(pathname, item.href);
+                            return (
+                              <button
+                                key={item.href}
+                                type="button"
+                                className={`block w-full rounded px-3 py-1.5 text-left text-sm ${
+                                  linkActive ? "bg-zinc-900 text-white" : "hover:bg-zinc-100"
+                                }`}
+                                onClick={() => {
+                                  setDesktopOpenGroup(null);
+                                  router.push(item.href);
+                                }}
+                              >
+                                {item.label}
+                              </button>
+                            );
+                          })}
+                        </div>
+                      )}
+                    </div>
+                  );
+                })}
+              </div>
+            ) : (
+              <>
+                <div className="hidden flex-wrap items-center gap-2 md:flex">
+                  {navGroups.map((group) => {
+                    const active = activeGroup === group.key;
+                    return (
+                      <button
+                        key={group.key}
+                        type="button"
+                        className={`rounded-md border px-3 py-1 text-sm ${
+                          active ? "border-zinc-900 bg-zinc-900 text-white" : "hover:bg-zinc-100"
+                        }`}
+                        onClick={() => router.push(group.links[0]?.href ?? "/")}
+                      >
+                        {group.label}
+                      </button>
+                    );
+                  })}
+                </div>
+
+                <div className="hidden items-center gap-2 md:flex">
+                  <span className="text-xs text-zinc-500">{t("nav.secondary_menu")}</span>
+                  <select
+                    className="min-w-[220px] rounded-md border px-3 py-1 text-sm"
+                    value={resolveActiveLink(pathname, currentGroup)}
+                    onChange={(e) => router.push(e.target.value)}
+                  >
+                    {currentGroup.links.map((item) => (
+                      <option key={item.href} value={item.href}>
+                        {item.label}
+                      </option>
+                    ))}
+                  </select>
+                </div>
+              </>
+            )}
+
+            <div className="space-y-3 md:hidden">
+              {navGroups.map((group) => (
+                <section key={group.key} className="rounded-lg border p-2">
+                  <h3 className="text-xs font-semibold text-zinc-600">{group.label}</h3>
+                  <select
+                    className="mt-2 w-full rounded-md border px-3 py-1 text-xs"
+                    value={resolveActiveLink(pathname, group)}
+                    onChange={(e) => {
+                      setMenuOpen(false);
+                      router.push(e.target.value);
+                    }}
+                  >
+                    {group.links.map((item) => (
+                      <option key={item.href} value={item.href}>
+                        {item.label}
+                      </option>
+                    ))}
+                  </select>
+                </section>
+              ))}
+            </div>
+          </div>
+        </div>
+
+        <div className="mt-2 flex flex-wrap items-center justify-end gap-2 text-xs sm:text-sm">
+          <label className="inline-flex items-center gap-1">
+            <span className="text-zinc-500">{t("prefs.theme")}</span>
+            <select
+              className="rounded-md border px-2 py-1 text-xs sm:text-sm"
+              value={theme}
+              onChange={(e) => {
+                setDesktopOpenGroup(null);
+                setTheme(e.target.value as ThemeId);
+              }}
+            >
+              {themes.map((item) => (
+                <option key={item.id} value={item.id}>
+                  {item.labels[language]}
+                </option>
+              ))}
+            </select>
+          </label>
+          <label className="inline-flex items-center gap-1">
+            <span className="text-zinc-500">{t("prefs.language")}</span>
+            <select
+              className="rounded-md border px-2 py-1 text-xs sm:text-sm"
+              value={language}
+              onChange={(e) => setLanguage(e.target.value === "zh" ? "zh" : "en")}
+            >
+              <option value="en">{t("prefs.lang.en")}</option>
+              <option value="zh">{t("prefs.lang.zh")}</option>
+            </select>
+          </label>
           <span className={hasToken ? "text-emerald-700" : "text-zinc-500"}>
-            {hasToken ? "已登录" : "未登录"}
+            {hasToken ? t("nav.logged_in") : t("nav.logged_out")}
           </span>
           {hasToken && (
             <button
               onClick={() => {
                 clearToken();
                 setHasToken(false);
+                setIsAdmin(false);
               }}
               className="rounded-md border px-3 py-1 hover:bg-zinc-100"
             >
-              退出
+              {t("nav.logout")}
             </button>
           )}
         </div>

frontend/src/components/code-editor.tsx

@@ -1,25 +1,160 @@
 "use client";
 
 import dynamic from "next/dynamic";
+import { useCallback, useEffect, useRef } from "react";
+import type { editor as MonacoEditorNS, IDisposable, MarkerSeverity, IPosition } from "monaco-editor";
+
+import { analyzeCpp14Policy, type Cpp14PolicyIssue } from "@/lib/cpp14-policy";
+import { useI18nText } from "@/lib/i18n";
 
 const MonacoEditor = dynamic(() => import("@monaco-editor/react"), { ssr: false });
+const POLICY_MARKER_OWNER = "csp-cpp14-policy";
 
 type Props = {
   value: string;
   onChange: (next: string) => void;
   height?: string;
+  fontSize?: number;
+  onPolicyIssuesChange?: (issues: Cpp14PolicyIssue[]) => void;
 };
 
-export function CodeEditor({ value, onChange, height = "420px" }: Props) {
+function markerSeverity(monaco: typeof import("monaco-editor"), severity: Cpp14PolicyIssue["severity"]): MarkerSeverity {
+  if (severity === "error") return monaco.MarkerSeverity.Error;
+  if (severity === "warning") return monaco.MarkerSeverity.Warning;
+  if (severity === "hint") return monaco.MarkerSeverity.Hint;
+  return monaco.MarkerSeverity.Info;
+}
+
+function safeEndPosition(
+  issue: Cpp14PolicyIssue,
+  model: MonacoEditorNS.ITextModel
+): IPosition {
+  const lineMax = model.getLineCount();
+  const line = Math.min(Math.max(1, issue.endLine), lineMax);
+  const colMax = model.getLineMaxColumn(line);
+  const column = Math.min(Math.max(1, issue.endColumn), colMax);
+  return { lineNumber: line, column };
+}
+
+function localizePolicyIssue(
+  issue: Cpp14PolicyIssue,
+  tx: (zhText: string, enText: string) => string
+): Cpp14PolicyIssue {
+  const byId: Record<string, { message: string; detail: string }> = {
+    "cpp17-header": {
+      message: tx("检测到 C++17+ 头文件", "Detected C++17+ header"),
+      detail: tx(
+        "福建 CSP-J/S 环境通常以 C++14 为准，建议改为 C++14 可用写法。",
+        "Fujian CSP-J/S judge usually targets C++14; please rewrite with C++14-compatible code."
+      ),
+    },
+    "if-constexpr": {
+      message: tx("检测到 if constexpr（C++17）", "Detected `if constexpr` (C++17)"),
+      detail: tx("请改用普通条件分支或模板特化方案。", "Use normal condition branches or template specialization."),
+    },
+    "structured-binding": {
+      message: tx("检测到结构化绑定（C++17）", "Detected structured binding (C++17)"),
+      detail: tx("可改为 pair.first/second 或自定义结构体字段。", "Use `pair.first/second` or explicit struct fields."),
+    },
+    "cpp17-stdlib": {
+      message: tx("检测到 C++17+ 标准库符号", "Detected C++17+ stdlib symbol"),
+      detail: tx("请替换为 C++14 可用实现，避免提交到老版本 GCC 报 CE。", "Replace with C++14 implementation to avoid CE on older GCC."),
+    },
+    "void-main": {
+      message: tx("main 函数返回类型不规范", "Invalid `main` return type"),
+      detail: tx("请使用 int main()，并在末尾 return 0;", "Use `int main()` and end with `return 0;`."),
+    },
+    "windows-i64d": {
+      message: tx("检测到 %I64d（Windows 特有）", "Detected `%I64d` (Windows-only)"),
+      detail: tx("Linux 评测机请使用 %lld 读写 long long。", "Use `%lld` for `long long` on Linux judges."),
+    },
+    "windows-int64": {
+      message: tx("检测到 __int64（非标准）", "Detected `__int64` (non-standard)"),
+      detail: tx("建议改为标准类型 long long。", "Use standard type `long long` instead."),
+    },
+    "bits-header": {
+      message: tx("检测到 <bits/stdc++.h>", "Detected `<bits/stdc++.h>`"),
+      detail: tx("福建实战建议优先使用标准头文件，提升环境兼容性。", "Prefer standard headers for better judge compatibility."),
+    },
+    "main-return-zero": {
+      message: tx("建议在 main 末尾显式 return 0;", "Recommend explicit `return 0;` in `main`"),
+      detail: tx("部分考场与评测环境会严格检查主函数返回行为。", "Some exam/judge environments check main return behavior strictly."),
+    },
+    "ll-format": {
+      message: tx("检测到 long long + scanf/printf，建议确认格式符为 %lld", "Detected `long long` with scanf/printf; confirm `%lld` format"),
+      detail: tx("Linux 评测环境不支持 %I64d。", "Linux judge does not support `%I64d`."),
+    },
+    "freopen-tip": {
+      message: tx("未检测到 freopen（福建二轮常见文件读写要求）", "No `freopen` found (common requirement in Fujian round-2)"),
+      detail: tx("若考场题面要求 *.in/*.out，请按官方文件名补上 freopen。", "If statement requires `*.in/*.out`, add `freopen` with exact official filenames."),
+    },
+  };
+  const localized = byId[issue.id];
+  if (!localized) return issue;
+  return { ...issue, ...localized };
+}
+
+export function CodeEditor({
+  value,
+  onChange,
+  height = "420px",
+  fontSize = 14,
+  onPolicyIssuesChange,
+}: Props) {
+  const { tx } = useI18nText();
+  const editorRef = useRef<MonacoEditorNS.IStandaloneCodeEditor | null>(null);
+  const monacoRef = useRef<typeof import("monaco-editor") | null>(null);
+  const completionRef = useRef<IDisposable | null>(null);
+
+  const updatePolicyIssues = useCallback(
+    (nextCode: string) => {
+      const issues = analyzeCpp14Policy(nextCode).map((issue) => localizePolicyIssue(issue, tx));
+      onPolicyIssuesChange?.(issues);
+
+      const monaco = monacoRef.current;
+      const model = editorRef.current?.getModel();
+      if (!monaco || !model) return;
+
+      const markers = issues.map((issue) => {
+        const endPos = safeEndPosition(issue, model);
+        return {
+          severity: markerSeverity(monaco, issue.severity),
+          message: `${issue.message}\n${issue.detail}`,
+          startLineNumber: Math.max(1, issue.line),
+          startColumn: Math.max(1, issue.column),
+          endLineNumber: endPos.lineNumber,
+          endColumn: endPos.column,
+          source: tx("CSP C++14 规范提醒", "CSP C++14 Policy"),
+          code: issue.id,
+        };
+      });
+      monaco.editor.setModelMarkers(model, POLICY_MARKER_OWNER, markers);
+    },
+    [onPolicyIssuesChange, tx]
+  );
+
+  useEffect(() => {
+    updatePolicyIssues(value);
+  }, [updatePolicyIssues, value]);
+
+  useEffect(
+    () => () => {
+      completionRef.current?.dispose();
+      completionRef.current = null;
+    },
+    []
+  );
+
   return (
     <MonacoEditor
       height={height}
       language="cpp"
       value={value}
       options={{
-        fontSize: 14,
+        fontSize,
         minimap: { enabled: false },
         automaticLayout: true,
+        glyphMargin: true,
         tabSize: 2,
         wordWrap: "on",
         suggestOnTriggerCharacters: true,
@@ -30,40 +165,98 @@ export function CodeEditor({ value, onChange, height = "420px" }: Props) {
         },
       }}
       onMount={(editor, monaco) => {
-        monaco.languages.registerCompletionItemProvider("cpp", {
-          provideCompletionItems: () => ({
-            suggestions: [
-              {
-                label: "ios",
-                kind: monaco.languages.CompletionItemKind.Snippet,
-                insertText:
-                  "ios::sync_with_stdio(false);\\ncin.tie(nullptr);\\n",
-                documentation: "Fast IO",
-              },
-              {
-                label: "fori",
-                kind: monaco.languages.CompletionItemKind.Snippet,
-                insertText: "for (int i = 0; i < ${1:n}; ++i) {\\n  ${2}\\n}",
-                insertTextRules:
-                  monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
-                documentation: "for loop",
-              },
-              {
-                label: "vector",
-                kind: monaco.languages.CompletionItemKind.Keyword,
-                insertText: "vector<int> ${1:arr}(${2:n});",
-                insertTextRules:
-                  monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
-              },
-            ],
-          }),
-        });
+        editorRef.current = editor;
+        monacoRef.current = monaco;
+
+        if (!completionRef.current) {
+          completionRef.current = monaco.languages.registerCompletionItemProvider("cpp", {
+            provideCompletionItems: () => ({
+              suggestions: [
+                {
+                  label: "cspmain",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText: [
+                    "#include <iostream>",
+                    "#include <vector>",
+                    "#include <algorithm>",
+                    "using namespace std;",
+                    "",
+                    "int main() {",
+                    "  ios::sync_with_stdio(false);",
+                    "  cin.tie(nullptr);",
+                    "",
+                    "  ${1:// code}",
+                    "  return 0;",
+                    "}",
+                  ].join("\\n"),
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                  documentation: tx("C++14 主函数模板（含 return 0）", "C++14 `main` template (with `return 0`)"),
+                },
+                {
+                  label: "ios",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText:
+                    "ios::sync_with_stdio(false);\\ncin.tie(nullptr);\\n",
+                  documentation: "Fast IO",
+                },
+                {
+                  label: "freopen",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText: [
+                    'freopen("${1:problem}.in", "r", stdin);',
+                    'freopen("${1:problem}.out", "w", stdout);',
+                  ].join("\\n"),
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                  documentation: tx("福建赛场常见文件读写模板", "Common Fujian contest file I/O template"),
+                },
+                {
+                  label: "scanfll",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText: 'scanf("%lld", &${1:x});',
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                  documentation: tx("long long 输入（Linux 评测格式符）", "long long input (Linux judge format)"),
+                },
+                {
+                  label: "printfll",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText: 'printf("%lld\\\\n", ${1:x});',
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                  documentation: tx("long long 输出（Linux 评测格式符）", "long long output (Linux judge format)"),
+                },
+                {
+                  label: "fori",
+                  kind: monaco.languages.CompletionItemKind.Snippet,
+                  insertText: "for (int i = 0; i < ${1:n}; ++i) {\\n  ${2}\\n}",
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                  documentation: "for loop",
+                },
+                {
+                  label: "vector",
+                  kind: monaco.languages.CompletionItemKind.Keyword,
+                  insertText: "vector<int> ${1:arr}(${2:n});",
+                  insertTextRules:
+                    monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet,
+                },
+              ],
+            }),
+          });
+        }
+        updatePolicyIssues(editor.getValue());
 
         editor.addCommand(monaco.KeyMod.CtrlCmd | monaco.KeyCode.KeyS, () => {
           // handled by page-level save button; reserve shortcut for UX consistency.
         });
       }}
-      onChange={(next) => onChange(next ?? "")}
+      onChange={(next) => {
+        const nextCode = next ?? "";
+        onChange(nextCode);
+        updatePolicyIssues(nextCode);
+      }}
     />
   );
 }

frontend/src/components/mobile-tab-bar.tsx

@@ -0,0 +1,49 @@
+"use client";
+
+import Link from "next/link";
+import { usePathname } from "next/navigation";
+
+import { useUiPreferences } from "@/components/ui-preference-provider";
+
+function isActivePath(pathname: string, href: string): boolean {
+  if (pathname === href) return true;
+  return pathname.startsWith(`${href}/`);
+}
+
+export function MobileTabBar() {
+  const pathname = usePathname();
+  const { t } = useUiPreferences();
+
+  const tabs = [
+    { label: t("mobile.tab.problems"), href: "/problems" },
+    { label: t("mobile.tab.submissions"), href: "/submissions" },
+    { label: t("mobile.tab.contests"), href: "/contests" },
+    { label: t("mobile.tab.kb"), href: "/kb" },
+    { label: t("mobile.tab.me"), href: "/me" },
+  ] as const;
+
+  return (
+    <nav className="print-hidden fixed inset-x-0 bottom-0 z-40 border-t bg-[color:var(--surface)]/95 pb-[calc(0.3rem+env(safe-area-inset-bottom))] pt-1 backdrop-blur supports-[backdrop-filter]:bg-[color:var(--surface)]/85 md:hidden">
+      <div className="mx-auto max-w-5xl px-2 max-[390px]:px-1.5">
+        <div className="grid grid-cols-5 gap-1 max-[390px]:gap-0.5">
+          {tabs.map((tab) => {
+            const active = isActivePath(pathname, tab.href);
+            return (
+              <Link
+                key={tab.href}
+                href={tab.href}
+                className={`rounded-md px-1 py-1.5 text-center text-xs max-[390px]:text-[11px] ${
+                  active
+                    ? "bg-zinc-900 font-semibold text-white"
+                    : "text-zinc-600 hover:bg-zinc-100"
+                }`}
+              >
+                {tab.label}
+              </Link>
+            );
+          })}
+        </div>
+      </div>
+    </nav>
+  );
+}

frontend/src/components/ui-preference-provider.tsx

@@ -0,0 +1,71 @@
+"use client";
+
+import { createContext, useContext, useEffect, useMemo, useState } from "react";
+
+import { listThemes, resolveLanguage, resolveTheme } from "@/themes/registry";
+import { DEFAULT_LANGUAGE, DEFAULT_THEME, type ThemeDefinition, type ThemeId, type UiLanguage } from "@/themes/types";
+
+const THEME_STORAGE_KEY = "csp.ui.theme";
+const LANGUAGE_STORAGE_KEY = "csp.ui.language";
+
+type UiPreferenceContextValue = {
+  theme: ThemeId;
+  language: UiLanguage;
+  themes: ThemeDefinition[];
+  setTheme: (theme: ThemeId) => void;
+  setLanguage: (language: UiLanguage) => void;
+  t: (key: string) => string;
+};
+
+const UiPreferenceContext = createContext<UiPreferenceContextValue | null>(null);
+
+export function UiPreferenceProvider({ children }: { children: React.ReactNode }) {
+  const [theme, setThemeState] = useState<ThemeId>(() => {
+    if (typeof window === "undefined") return DEFAULT_THEME;
+    return resolveTheme(window.localStorage.getItem(THEME_STORAGE_KEY)).id;
+  });
+  const [language, setLanguageState] = useState<UiLanguage>(() => {
+    if (typeof window === "undefined") return DEFAULT_LANGUAGE;
+    return resolveLanguage(window.localStorage.getItem(LANGUAGE_STORAGE_KEY));
+  });
+  const themes = useMemo(() => listThemes(), []);
+
+  useEffect(() => {
+    if (typeof window !== "undefined") {
+      window.localStorage.setItem(THEME_STORAGE_KEY, theme);
+    }
+    document.documentElement.dataset.theme = theme;
+  }, [theme]);
+
+  useEffect(() => {
+    if (typeof window !== "undefined") {
+      window.localStorage.setItem(LANGUAGE_STORAGE_KEY, language);
+    }
+    document.documentElement.lang = language === "zh" ? "zh-CN" : "en";
+  }, [language]);
+
+  const value = useMemo<UiPreferenceContextValue>(() => {
+    const resolved = resolveTheme(theme);
+    const fallbackMessages = resolved.messages.en;
+    const currentMessages = resolved.messages[language] ?? fallbackMessages;
+
+    return {
+      theme,
+      language,
+      themes,
+      setTheme: (nextTheme) => setThemeState(resolveTheme(nextTheme).id),
+      setLanguage: (nextLanguage) => setLanguageState(resolveLanguage(nextLanguage)),
+      t: (key: string) => currentMessages[key] ?? fallbackMessages[key] ?? key,
+    };
+  }, [language, theme, themes]);
+
+  return <UiPreferenceContext.Provider value={value}>{children}</UiPreferenceContext.Provider>;
+}
+
+export function useUiPreferences() {
+  const ctx = useContext(UiPreferenceContext);
+  if (!ctx) {
+    throw new Error("useUiPreferences must be used inside UiPreferenceProvider");
+  }
+  return ctx;
+}

frontend/src/lib/api.ts

@@ -2,6 +2,12 @@ export const API_BASE =
   process.env.NEXT_PUBLIC_API_BASE ??
   (process.env.NODE_ENV === "development" ? "http://localhost:8080" : "/admin139");
 
+function uiText(zhText: string, enText: string): string {
+  if (typeof window === "undefined") return enText;
+  const lang = window.localStorage.getItem("csp.ui.language");
+  return lang === "zh" ? zhText : enText;
+}
+
 type ApiEnvelope<T> =
   | { ok: true; data?: T; [k: string]: unknown }
   | { ok: false; error?: string; [k: string]: unknown };
@@ -17,11 +23,45 @@ export async function apiFetch<T>(
     headers.set("Content-Type", "application/json");
   }
 
-  const resp = await fetch(`${API_BASE}${path}`, {
-    ...init,
-    headers,
-    cache: "no-store",
-  });
+  const method = (init?.method ?? "GET").toUpperCase();
+  const retryable = method === "GET" || method === "HEAD";
+
+  let resp: Response;
+  try {
+    resp = await fetch(`${API_BASE}${path}`, {
+      ...init,
+      headers,
+      cache: "no-store",
+    });
+  } catch (err) {
+    if (!retryable) {
+      throw new Error(
+        uiText(
+          `网络请求失败，请检查后端服务或代理连接（${err instanceof Error ? err.message : String(err)}）`,
+          `Network request failed. Please check backend/proxy connectivity (${err instanceof Error ? err.message : String(err)}).`
+        )
+      );
+    }
+    await new Promise((resolve) => setTimeout(resolve, 400));
+    try {
+      resp = await fetch(`${API_BASE}${path}`, {
+        ...init,
+        headers,
+        cache: "no-store",
+      });
+    } catch (retryErr) {
+      throw new Error(
+        uiText(
+          `网络请求失败，请检查后端服务或代理连接（${
+            retryErr instanceof Error ? retryErr.message : String(retryErr)
+          }）`,
+          `Network request failed. Please check backend/proxy connectivity (${
+            retryErr instanceof Error ? retryErr.message : String(retryErr)
+          }).`
+        )
+      );
+    }
+  }
 
   const text = await resp.text();
   let payload: unknown = null;

frontend/src/lib/cpp14-policy.ts

@@ -0,0 +1,206 @@
+export type Cpp14PolicySeverity = "error" | "warning" | "hint";
+
+export type Cpp14PolicyIssue = {
+  id: string;
+  severity: Cpp14PolicySeverity;
+  message: string;
+  detail: string;
+  line: number;
+  column: number;
+  endLine: number;
+  endColumn: number;
+};
+
+type RegexRule = {
+  id: string;
+  severity: Cpp14PolicySeverity;
+  pattern: RegExp;
+  message: string;
+  detail: string;
+};
+
+const REGEX_RULES: RegexRule[] = [
+  {
+    id: "cpp17-header",
+    severity: "error",
+    pattern: /#\s*include\s*<\s*(optional|variant|any|string_view|filesystem|charconv|execution)\s*>/g,
+    message: "检测到 C++17+ 头文件",
+    detail: "福建 CSP-J/S 环境通常以 C++14 为准，建议改为 C++14 可用写法。",
+  },
+  {
+    id: "if-constexpr",
+    severity: "error",
+    pattern: /\bif\s+constexpr\b/g,
+    message: "检测到 if constexpr（C++17）",
+    detail: "请改用普通条件分支或模板特化方案。",
+  },
+  {
+    id: "structured-binding",
+    severity: "error",
+    pattern: /\b(?:const\s+)?auto(?:\s*&|\s*&&)?\s*\[[^\]\n]+\]\s*=/g,
+    message: "检测到结构化绑定（C++17）",
+    detail: "可改为 pair.first/second 或自定义结构体字段。",
+  },
+  {
+    id: "cpp17-stdlib",
+    severity: "error",
+    pattern: /\bstd::(optional|variant|any|string_view|filesystem|byte|clamp|gcd|lcm)\b/g,
+    message: "检测到 C++17+ 标准库符号",
+    detail: "请替换为 C++14 可用实现，避免提交到老版本 GCC 报 CE。",
+  },
+  {
+    id: "void-main",
+    severity: "error",
+    pattern: /\bvoid\s+main\s*\(/g,
+    message: "main 函数返回类型不规范",
+    detail: "请使用 int main()，并在末尾 return 0;",
+  },
+  {
+    id: "windows-i64d",
+    severity: "warning",
+    pattern: /%I64d/g,
+    message: "检测到 %I64d（Windows 特有）",
+    detail: "Linux 评测机请使用 %lld 读写 long long。",
+  },
+  {
+    id: "windows-int64",
+    severity: "warning",
+    pattern: /\b__int64\b/g,
+    message: "检测到 __int64（非标准）",
+    detail: "建议改为标准类型 long long。",
+  },
+  {
+    id: "bits-header",
+    severity: "warning",
+    pattern: /#\s*include\s*<\s*bits\/stdc\+\+\.h\s*>/g,
+    message: "检测到 <bits/stdc++.h>",
+    detail: "福建实战建议优先使用标准头文件，提升环境兼容性。",
+  },
+];
+
+export const CSP_CPP14_TIPS: string[] = [
+  "编译标准固定为 C++14（建议按 -std=gnu++14 习惯编码），不要使用 C++17+ 特性。",
+  "main 必须是 int main()，结尾写 return 0;。",
+  "long long 的 scanf/printf 请使用 %lld，不要使用 %I64d。",
+  "命名/提交包按考场须知执行：题目目录与源码名使用英文小写。",
+  "福建二轮常见要求是文件读写（freopen），赛前请按官方样例再核对一次。",
+];
+
+function buildLineStarts(text: string): number[] {
+  const starts = [0];
+  for (let i = 0; i < text.length; i += 1) {
+    if (text[i] === "\n") starts.push(i + 1);
+  }
+  return starts;
+}
+
+function offsetToPosition(lineStarts: number[], offset: number): { line: number; column: number } {
+  let lo = 0;
+  let hi = lineStarts.length - 1;
+  while (lo <= hi) {
+    const mid = (lo + hi) >> 1;
+    if (lineStarts[mid] <= offset) lo = mid + 1;
+    else hi = mid - 1;
+  }
+  const lineIdx = Math.max(0, hi);
+  return {
+    line: lineIdx + 1,
+    column: offset - lineStarts[lineIdx] + 1,
+  };
+}
+
+function pushIssue(
+  issues: Cpp14PolicyIssue[],
+  id: string,
+  severity: Cpp14PolicySeverity,
+  message: string,
+  detail: string,
+  line: number,
+  column: number,
+  endLine: number,
+  endColumn: number
+) {
+  issues.push({ id, severity, message, detail, line, column, endLine, endColumn });
+}
+
+export function analyzeCpp14Policy(code: string): Cpp14PolicyIssue[] {
+  const text = (code ?? "").replace(/\r\n?/g, "\n");
+  if (!text.trim()) return [];
+
+  const issues: Cpp14PolicyIssue[] = [];
+  const lineStarts = buildLineStarts(text);
+
+  for (const rule of REGEX_RULES) {
+    const matcher = new RegExp(rule.pattern.source, rule.pattern.flags);
+    let match = matcher.exec(text);
+    while (match) {
+      const start = match.index;
+      const end = start + Math.max(1, match[0].length);
+      const p1 = offsetToPosition(lineStarts, start);
+      const p2 = offsetToPosition(lineStarts, end);
+      pushIssue(
+        issues,
+        rule.id,
+        rule.severity,
+        rule.message,
+        rule.detail,
+        p1.line,
+        p1.column,
+        p2.line,
+        p2.column
+      );
+      if (matcher.lastIndex === match.index) matcher.lastIndex += 1;
+      match = matcher.exec(text);
+    }
+  }
+
+  if (/\bint\s+main\s*\(/.test(text) && !/\breturn\s+0\s*;/.test(text)) {
+    const idx = text.search(/\bint\s+main\s*\(/);
+    const pos = offsetToPosition(lineStarts, Math.max(0, idx));
+    pushIssue(
+      issues,
+      "main-return-zero",
+      "warning",
+      "建议在 main 末尾显式 return 0;",
+      "部分考场与评测环境会严格检查主函数返回行为。",
+      pos.line,
+      pos.column,
+      pos.line,
+      pos.column + 3
+    );
+  }
+
+  if (/\blong\s+long\b/.test(text) && /\b(?:scanf|printf)\s*\(/.test(text) && !/%lld/.test(text)) {
+    const idx = text.search(/\b(?:scanf|printf)\s*\(/);
+    const pos = offsetToPosition(lineStarts, Math.max(0, idx));
+    pushIssue(
+      issues,
+      "ll-format",
+      "warning",
+      "检测到 long long + scanf/printf，建议确认格式符为 %lld",
+      "Linux 评测环境不支持 %I64d。",
+      pos.line,
+      pos.column,
+      pos.line,
+      pos.column + 6
+    );
+  }
+
+  if (!/\bfreopen\s*\(/.test(text) && /\bint\s+main\s*\(/.test(text)) {
+    const idx = text.search(/\bint\s+main\s*\(/);
+    const pos = offsetToPosition(lineStarts, Math.max(0, idx));
+    pushIssue(
+      issues,
+      "freopen-tip",
+      "hint",
+      "未检测到 freopen（福建二轮常见文件读写要求）",
+      "若考场题面要求 *.in/*.out，请按官方文件名补上 freopen。",
+      pos.line,
+      pos.column,
+      pos.line,
+      pos.column + 3
+    );
+  }
+
+  return issues;
+}

frontend/src/lib/i18n.ts

@@ -0,0 +1,15 @@
+"use client";
+
+import { useUiPreferences } from "@/components/ui-preference-provider";
+
+export function readUiLanguage(): "en" | "zh" {
+  if (typeof window === "undefined") return "en";
+  return window.localStorage.getItem("csp.ui.language") === "zh" ? "zh" : "en";
+}
+
+export function useI18nText() {
+  const { language } = useUiPreferences();
+  const isZh = language === "zh";
+  const tx = (zhText: string, enText: string) => (isZh ? zhText : enText);
+  return { language, isZh, tx };
+}

frontend/src/themes/README.md

@@ -0,0 +1,294 @@
+# 前端主题开发规范（Theme Development Guide）
+
+本规范用于统一 `frontend/src/themes` 的主题实现方式，确保：
+
+- 主题切换稳定（不闪烁、不丢样式、可回退）。
+- 中英文文案与主题样式解耦。
+- 新主题可快速复制、低风险上线。
+- 代码评审和验收有统一标准。
+
+---
+
+## 1. 当前主题系统结构
+
+```text
+src/themes/
+  README.md
+  types.ts
+  registry.ts
+  default/
+    index.ts
+    theme.css
+    messages/
+      en.ts
+      zh.ts
+  minecraft/
+    index.ts
+    theme.css
+```
+
+相关运行时入口：
+
+- `frontend/src/components/ui-preference-provider.tsx`
+  - 读取/写入本地偏好：
+    - `csp.ui.theme`
+    - `csp.ui.language`
+  - 将主题写入：`document.documentElement.dataset.theme`
+  - 将语言写入：`document.documentElement.lang`
+- `frontend/src/app/layout.tsx`
+  - 必须导入所有主题 CSS 文件（否则构建后不会产出样式）。
+
+---
+
+## 2. 主题模型与命名规范
+
+### 2.1 ThemeId
+
+`src/themes/types.ts` 的 `ThemeId` 使用联合类型，新增主题必须显式加入：
+
+```ts
+export type ThemeId = "default" | "minecraft";
+```
+
+### 2.2 目录命名
+
+- 目录名使用小写短横线或小写单词（建议与 `ThemeId` 一致）。
+- 推荐：
+  - `default`
+  - `minecraft`
+- 不推荐：
+  - `MinecraftTheme`
+  - `theme_minecraft_v2`
+
+### 2.3 主题显示名
+
+在 `<theme>/index.ts` 的 `labels` 中定义：
+
+- `en`: 英文名称
+- `zh`: 中文名称
+
+示例：
+
+```ts
+labels: {
+  en: "Minecraft Pixel",
+  zh: "Minecraft 像素风",
+}
+```
+
+---
+
+## 3. 主题文件职责划分
+
+### 3.1 `types.ts`
+
+职责：
+
+- 主题类型与默认主题定义。
+
+禁止：
+
+- 放置主题样式、业务逻辑。
+
+### 3.2 `registry.ts`
+
+职责：
+
+- 注册所有主题。
+- 提供 `listThemes` / `resolveTheme` / `resolveLanguage`。
+
+规范：
+
+- 新主题必须加入 `themes` 数组。
+- `resolveTheme` 必须有回退逻辑（回退到 `DEFAULT_THEME`）。
+
+### 3.3 `<theme>/index.ts`
+
+职责：
+
+- 只描述主题元数据（`id` / `labels` / `messages`）。
+
+规范：
+
+- 不写样式代码。
+- 可复用默认消息包，也可提供主题专属消息包。
+
+### 3.4 `<theme>/theme.css`
+
+职责：
+
+- 主题 token 与组件样式覆盖。
+
+规范：
+
+- 必须以 `:root[data-theme="<id>"]` 作为作用域入口。
+- 优先 token 化，减少硬编码。
+- 避免直接污染无作用域的全局选择器。
+
+---
+
+## 4. CSS 实现规范（强制）
+
+### 4.1 作用域规则
+
+必须：
+
+- 使用 `:root[data-theme="<id>"]` 作为根作用域。
+- 仅在该作用域下覆盖样式。
+
+示例：
+
+```css
+:root[data-theme="minecraft"] {
+  --background: #1a1a1a;
+  --foreground: #f5f5f5;
+}
+```
+
+### 4.2 Token 优先级
+
+实现顺序：
+
+1. 先定义 CSS 变量（颜色、边框、背景、文本）。
+2. 业务组件尽量走变量消费。
+3. 最后才做类级别覆盖（如 `.rounded-xl.border`）。
+
+### 4.3 覆盖策略
+
+推荐：
+
+- 小范围、可预测覆盖（导航、按钮、卡片、输入等）。
+
+谨慎：
+
+- `!important` 仅用于必要冲突点。
+- 覆盖 Tailwind 工具类时，需评估全站影响。
+
+### 4.4 字体规范
+
+推荐：
+
+- `font-display: swap`。
+- 提供回退字体链。
+
+注意：
+
+- 外链字体失败时应可读、不崩布局。
+
+---
+
+## 5. 国际化（i18n）规范
+
+### 5.1 文案层级
+
+- 主题消息通过 `ThemeDefinition.messages` 提供。
+- 页面业务文案使用 `tx(zh, en)` 或 `t(key)`。
+
+### 5.2 主题与文案关系
+
+- 主题可以复用默认 `en/zh` 消息包（如 `minecraft`）。
+- 如主题有独立文案（例如术语、品牌），再创建主题专属 `messages`。
+
+### 5.3 必查项
+
+- 主题切换不影响语言切换。
+- EN 模式不出现未预期中文 UI 文案（数据内容除外）。
+
+---
+
+## 6. 新增主题标准流程（SOP）
+
+1. 新建目录 `src/themes/<id>/`。
+2. 新建 `<id>/theme.css`（先 token，后覆盖）。
+3. 新建 `<id>/index.ts`（主题元数据）。
+4. 在 `types.ts` 扩展 `ThemeId` 联合类型。
+5. 在 `registry.ts` 注册主题。
+6. 在 `app/layout.tsx` 导入主题 CSS。
+7. 运行校验：
+   - `npm run lint`
+   - `npm run build`
+8. 手工验收：
+   - 主题切换
+   - 移动端导航
+   - 深色页面可读性
+   - 表单/按钮交互
+
+---
+
+## 7. 验收清单（上线前必须过）
+
+- 功能：
+  - 主题可切换、可持久化（刷新后保留）。
+  - 语言切换与主题切换互不影响。
+- 样式：
+  - 首页、题库、题目详情、提交详情、个人中心、后台页无明显错位。
+  - 按钮 hover/active/disabled 状态清晰。
+  - 输入框、下拉框、表格、代码区可读。
+- 技术：
+  - `npm run lint` 无报错。
+  - `npm run build` 成功。
+  - 无新增严重控制台报错。
+
+---
+
+## 8. Code Review 清单
+
+- 是否遵循 `:root[data-theme="<id>"]` 作用域？
+- 是否优先使用 token，而不是散落硬编码颜色？
+- 是否避免了无必要的大面积 `!important`？
+- `ThemeId`、`registry`、`layout` 三处是否同步更新？
+- 主题名称 `labels` 是否提供中英文？
+- 是否验证主要页面可读性与对比度？
+
+---
+
+## 9. Minecraft 主题落地说明（当前版本）
+
+来源参考：
+
+- `ref/CSP-Minecraft-UI-Kit/docs/Design-Delivery-Document.html`
+
+已落地核心规范：
+
+- 色板 token（grass/stone/wood/gold/diamond/redstone）。
+- 像素风容器与边框（黑边 + 阴影）。
+- 按钮 3D 状态（normal/hover/active/disabled）。
+- 输入控件像素化风格。
+- 背景纹理与图片 `image-rendering: pixelated`。
+- 标题字体与文本阴影风格。
+
+---
+
+## 10. 常见问题（FAQ）
+
+### Q1: 新主题写了 CSS，但页面无变化？
+
+优先检查：
+
+- `layout.tsx` 是否 `import` 了该主题 CSS。
+- `ThemeId` 是否包含该主题。
+- `registry.ts` 是否注册主题。
+- `data-theme` 是否正确写入到 `<html>`。
+
+### Q2: 主题切换后某些组件颜色不对？
+
+原因通常是：
+
+- 页面用了硬编码颜色类且未被主题覆盖。
+
+建议：
+
+- 先抽成 token，再局部覆盖组件类。
+
+### Q3: 能否让主题拥有独立文案？
+
+可以。把 `messages` 指向主题自己的 `en.ts / zh.ts` 即可。
+
+---
+
+## 11. 后续建议（可选）
+
+- 将“按钮、卡片、输入框、徽章”收敛为主题化组件（而非纯 class 覆盖）。
+- 增加主题视觉回归截图（关键页面自动快照）。
+- 建立对比度检测脚本，避免低对比度文本上线。
+

frontend/src/themes/default/index.ts

@@ -0,0 +1,15 @@
+import { enMessages } from "@/themes/default/messages/en";
+import { zhMessages } from "@/themes/default/messages/zh";
+import type { ThemeDefinition } from "@/themes/types";
+
+export const defaultTheme: ThemeDefinition = {
+  id: "default",
+  labels: {
+    en: "Default",
+    zh: "默认主题",
+  },
+  messages: {
+    en: enMessages,
+    zh: zhMessages,
+  },
+};

frontend/src/themes/default/messages/en.ts

@@ -0,0 +1,55 @@
+import type { ThemeMessages } from "@/themes/types";
+
+export const enMessages: ThemeMessages = {
+  "app.title": "CSP Online Learning & Contest Platform",
+
+  "nav.menu": "Navigation",
+  "nav.expand": "Expand",
+  "nav.collapse": "Collapse",
+  "nav.secondary_menu": "Submenu",
+  "nav.logged_in": "Signed in",
+  "nav.logged_out": "Signed out",
+  "nav.logout": "Sign out",
+
+  "nav.group.learn": "Learning",
+  "nav.group.contest": "Contests",
+  "nav.group.system": "Platform",
+  "nav.group.account": "Account",
+
+  "nav.link.home": "Home",
+  "nav.link.problems": "Problems",
+  "nav.link.submissions": "Submissions",
+  "nav.link.wrong_book": "Wrong Book",
+  "nav.link.kb": "Knowledge Base",
+  "nav.link.run": "Run Code",
+  "nav.link.contests": "Contests",
+  "nav.link.leaderboard": "Leaderboard",
+  "nav.link.imports": "Imports",
+  "nav.link.backend_logs": "Backend Logs",
+  "nav.link.admin_users": "User Rating",
+  "nav.link.admin_redeem": "Redeem Admin",
+  "nav.link.api_docs": "API Docs",
+  "nav.link.auth": "Sign In",
+  "nav.link.me": "My Account",
+
+  "mobile.tab.problems": "Problems",
+  "mobile.tab.submissions": "Submits",
+  "mobile.tab.contests": "Contests",
+  "mobile.tab.kb": "KB",
+  "mobile.tab.me": "Me",
+
+  "prefs.theme": "Theme",
+  "prefs.language": "Language",
+  "prefs.lang.en": "English",
+  "prefs.lang.zh": "Chinese",
+
+  "admin.entry.title": "Admin Entry",
+  "admin.entry.desc":
+    "Default admin account: admin / whoami139",
+  "admin.entry.login": "Go to Sign In",
+  "admin.entry.user_rating": "Manage User Rating",
+  "admin.entry.redeem": "Manage Redeem Items",
+  "admin.entry.logs": "Backend Task Logs",
+  "admin.entry.moved_to_platform":
+    "This entry has been merged into Platform Management (/imports).",
+};

frontend/src/themes/default/messages/zh.ts

@@ -0,0 +1,53 @@
+import type { ThemeMessages } from "@/themes/types";
+
+export const zhMessages: ThemeMessages = {
+  "app.title": "CSP 在线学习与竞赛平台",
+
+  "nav.menu": "导航菜单",
+  "nav.expand": "展开",
+  "nav.collapse": "收起",
+  "nav.secondary_menu": "二级菜单",
+  "nav.logged_in": "已登录",
+  "nav.logged_out": "未登录",
+  "nav.logout": "退出",
+
+  "nav.group.learn": "学习训练",
+  "nav.group.contest": "竞赛评测",
+  "nav.group.system": "平台管理",
+  "nav.group.account": "账号中心",
+
+  "nav.link.home": "首页",
+  "nav.link.problems": "题库",
+  "nav.link.submissions": "提交记录",
+  "nav.link.wrong_book": "错题本",
+  "nav.link.kb": "知识库",
+  "nav.link.run": "在线运行",
+  "nav.link.contests": "比赛",
+  "nav.link.leaderboard": "排行榜",
+  "nav.link.imports": "导入任务",
+  "nav.link.backend_logs": "后台日志",
+  "nav.link.admin_users": "用户积分",
+  "nav.link.admin_redeem": "积分兑换",
+  "nav.link.api_docs": "API文档",
+  "nav.link.auth": "登录",
+  "nav.link.me": "我的",
+
+  "mobile.tab.problems": "题库",
+  "mobile.tab.submissions": "提交",
+  "mobile.tab.contests": "比赛",
+  "mobile.tab.kb": "知识库",
+  "mobile.tab.me": "我的",
+
+  "prefs.theme": "主题",
+  "prefs.language": "语言",
+  "prefs.lang.en": "English",
+  "prefs.lang.zh": "中文",
+
+  "admin.entry.title": "后台管理入口",
+  "admin.entry.desc": "默认管理员账号：admin / whoami139",
+  "admin.entry.login": "去登录",
+  "admin.entry.user_rating": "用户积分管理",
+  "admin.entry.redeem": "积分兑换管理",
+  "admin.entry.logs": "后台任务日志",
+  "admin.entry.moved_to_platform": "该入口已并入“平台管理”页（/imports）。",
+};

frontend/src/themes/default/theme.css

@@ -0,0 +1,19 @@
+:root,
+:root[data-theme="default"] {
+  --background: #ffffff;
+  --foreground: #171717;
+  --surface: #ffffff;
+  --surface-soft: #f4f4f5;
+  --border: #d4d4d8;
+}
+
+@media (prefers-color-scheme: dark) {
+  :root,
+  :root[data-theme="default"] {
+    --background: #0a0a0a;
+    --foreground: #ededed;
+    --surface: #111111;
+    --surface-soft: #1f1f1f;
+    --border: #3f3f46;
+  }
+}

frontend/src/themes/minecraft/index.ts

@@ -0,0 +1,15 @@
+import { enMessages } from "@/themes/default/messages/en";
+import { zhMessages } from "@/themes/default/messages/zh";
+import type { ThemeDefinition } from "@/themes/types";
+
+export const minecraftTheme: ThemeDefinition = {
+  id: "minecraft",
+  labels: {
+    en: "Minecraft Pixel",
+    zh: "Minecraft 像素风",
+  },
+  messages: {
+    en: enMessages,
+    zh: zhMessages,
+  },
+};

frontend/src/themes/minecraft/theme.css

@@ -0,0 +1,201 @@
+@font-face {
+  font-family: "DelaGothicOne";
+  src: url("https://assets-persist.lovart.ai/agent-static-assets/DelaGothicOne-Regular.ttf");
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "MiSans";
+  src: url("https://assets-persist.lovart.ai/agent-static-assets/MiSans-Regular.ttf");
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "MiSansBold";
+  src: url("https://assets-persist.lovart.ai/agent-static-assets/MiSans-Bold.ttf");
+  font-display: swap;
+}
+
+:root[data-theme="minecraft"] {
+  --mc-grass-top: #5cb85c;
+  --mc-grass-side: #4cae4c;
+  --mc-dirt: #795548;
+  --mc-stone: #9e9e9e;
+  --mc-stone-dark: #616161;
+  --mc-obsidian: #212121;
+  --mc-wood: #8d6e63;
+  --mc-wood-dark: #5d4037;
+  --mc-gold: #ffd700;
+  --mc-diamond: #40e0d0;
+  --mc-redstone: #f44336;
+
+  --background: #1a1a1a;
+  --foreground: #f5f5f5;
+  --surface: #2d2d2d;
+  --surface-soft: #242424;
+  --border: #000000;
+}
+
+:root[data-theme="minecraft"] body {
+  background-color: var(--background);
+  background-image:
+    linear-gradient(rgba(26, 26, 26, 0.9), rgba(26, 26, 26, 0.9)),
+    url("https://a.lovart.ai/artifacts/agent/W1iXxVdg3xIm5fP9.png");
+  background-size: 320px 320px;
+  color: var(--foreground);
+  font-family: "MiSans", "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
+}
+
+:root[data-theme="minecraft"] h1,
+:root[data-theme="minecraft"] h2,
+:root[data-theme="minecraft"] h3,
+:root[data-theme="minecraft"] h4,
+:root[data-theme="minecraft"] h5,
+:root[data-theme="minecraft"] h6 {
+  color: #ffffff;
+  font-family: "DelaGothicOne", "MiSansBold", "MiSans", sans-serif;
+  letter-spacing: 0.04em;
+  text-shadow: 2px 2px 0 #000000;
+}
+
+:root[data-theme="minecraft"] ::-webkit-scrollbar {
+  width: 12px;
+  height: 12px;
+  background: var(--mc-obsidian);
+}
+
+:root[data-theme="minecraft"] ::-webkit-scrollbar-thumb {
+  background: var(--mc-stone);
+  border: 2px solid var(--mc-obsidian);
+}
+
+:root[data-theme="minecraft"] header.print-hidden {
+  background: rgba(33, 33, 33, 0.96) !important;
+  border-bottom: 4px solid var(--mc-stone-dark);
+  box-shadow: 0 4px 0 rgba(0, 0, 0, 0.35);
+}
+
+:root[data-theme="minecraft"] nav.print-hidden.fixed {
+  background: rgba(33, 33, 33, 0.96) !important;
+  border-top: 4px solid var(--mc-stone-dark);
+}
+
+:root[data-theme="minecraft"] .rounded-xl.border,
+:root[data-theme="minecraft"] .rounded-lg.border,
+:root[data-theme="minecraft"] .rounded-md.border,
+:root[data-theme="minecraft"] .rounded.border {
+  border-radius: 0 !important;
+  border-color: #000000 !important;
+  border-width: 3px !important;
+  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.45);
+}
+
+:root[data-theme="minecraft"] .bg-white {
+  background-color: #2d2d2d !important;
+}
+
+:root[data-theme="minecraft"] .bg-zinc-50 {
+  background-color: #252525 !important;
+}
+
+:root[data-theme="minecraft"] .bg-zinc-100 {
+  background-color: #343434 !important;
+}
+
+:root[data-theme="minecraft"] .text-zinc-400,
+:root[data-theme="minecraft"] .text-zinc-500,
+:root[data-theme="minecraft"] .text-zinc-600,
+:root[data-theme="minecraft"] .text-zinc-700 {
+  color: #d0d0d0 !important;
+}
+
+:root[data-theme="minecraft"] .text-blue-600,
+:root[data-theme="minecraft"] .text-blue-700 {
+  color: var(--mc-diamond) !important;
+}
+
+:root[data-theme="minecraft"] .text-emerald-700 {
+  color: var(--mc-grass-top) !important;
+}
+
+:root[data-theme="minecraft"] .text-amber-700,
+:root[data-theme="minecraft"] .text-amber-800 {
+  color: var(--mc-gold) !important;
+}
+
+:root[data-theme="minecraft"] .text-red-600,
+:root[data-theme="minecraft"] .text-red-700 {
+  color: var(--mc-redstone) !important;
+}
+
+:root[data-theme="minecraft"] button {
+  background: linear-gradient(180deg, var(--mc-stone) 0%, var(--mc-stone-dark) 100%) !important;
+  border: 3px solid #000000 !important;
+  border-bottom-width: 7px !important;
+  border-radius: 0 !important;
+  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.45);
+  color: #ffffff !important;
+  font-family: "DelaGothicOne", "MiSansBold", "MiSans", sans-serif;
+  letter-spacing: 0.03em;
+  text-shadow: 1px 1px 0 #000000;
+  transition: transform 0.08s ease, filter 0.08s ease;
+}
+
+:root[data-theme="minecraft"] button:hover:not(:disabled) {
+  filter: brightness(1.08);
+  transform: translateY(-1px);
+}
+
+:root[data-theme="minecraft"] button:active:not(:disabled) {
+  border-bottom-width: 3px !important;
+  transform: translateY(3px);
+}
+
+:root[data-theme="minecraft"] button:disabled {
+  filter: saturate(0.25);
+  opacity: 0.7;
+}
+
+:root[data-theme="minecraft"] input,
+:root[data-theme="minecraft"] textarea,
+:root[data-theme="minecraft"] select {
+  background: #1f1f1f !important;
+  border: 3px solid #000000 !important;
+  border-radius: 0 !important;
+  box-shadow: inset 2px 2px 0 rgba(255, 255, 255, 0.1);
+  color: #f2f2f2 !important;
+}
+
+:root[data-theme="minecraft"] input::placeholder,
+:root[data-theme="minecraft"] textarea::placeholder {
+  color: #acacac;
+}
+
+:root[data-theme="minecraft"] a {
+  color: var(--mc-diamond);
+}
+
+:root[data-theme="minecraft"] a:hover {
+  color: var(--mc-gold);
+}
+
+:root[data-theme="minecraft"] table thead {
+  background: #333333 !important;
+}
+
+:root[data-theme="minecraft"] table tr {
+  border-color: #000000 !important;
+}
+
+:root[data-theme="minecraft"] pre {
+  border: 2px solid #000000;
+  box-shadow: inset 1px 1px 0 rgba(255, 255, 255, 0.08);
+}
+
+:root[data-theme="minecraft"] img {
+  image-rendering: pixelated;
+}
+
+:root[data-theme="minecraft"] .problem-markdown-compact {
+  font-size: 66%;
+}

frontend/src/themes/registry.ts

@@ -0,0 +1,21 @@
+import { defaultTheme } from "@/themes/default";
+import { minecraftTheme } from "@/themes/minecraft";
+import { DEFAULT_LANGUAGE, DEFAULT_THEME, type ThemeDefinition, type ThemeId, type UiLanguage } from "@/themes/types";
+
+const themes: ThemeDefinition[] = [defaultTheme, minecraftTheme];
+
+const themeMap = new Map<ThemeId, ThemeDefinition>(themes.map((theme) => [theme.id, theme]));
+
+export function listThemes(): ThemeDefinition[] {
+  return themes;
+}
+
+export function resolveTheme(themeId: string | null | undefined): ThemeDefinition {
+  if (!themeId) return themeMap.get(DEFAULT_THEME) ?? defaultTheme;
+  return themeMap.get(themeId as ThemeId) ?? (themeMap.get(DEFAULT_THEME) ?? defaultTheme);
+}
+
+export function resolveLanguage(language: string | null | undefined): UiLanguage {
+  if (language === "zh") return "zh";
+  return DEFAULT_LANGUAGE;
+}

frontend/src/themes/types.ts

@@ -0,0 +1,13 @@
+export type ThemeId = "default" | "minecraft";
+export type UiLanguage = "en" | "zh";
+
+export const DEFAULT_THEME: ThemeId = "default";
+export const DEFAULT_LANGUAGE: UiLanguage = "en";
+
+export type ThemeMessages = Record<string, string>;
+
+export type ThemeDefinition = {
+  id: ThemeId;
+  labels: Record<UiLanguage, string>;
+  messages: Record<UiLanguage, ThemeMessages>;
+};

scripts/analyze_submission_feedback.py

@@ -0,0 +1,272 @@
+#!/usr/bin/env python3
+"""Generate CSP-J/S style feedback for one submission via LLM (with fallback)."""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import re
+import sys
+from dataclasses import dataclass
+from typing import Any, Dict, List, Optional
+
+import requests
+
+DEFAULT_LINKS: List[Dict[str, str]] = [
+    {"title": "NOI 官网（规则与环境）", "url": "https://www.noi.cn/"},
+    {"title": "OI Wiki（算法知识库）", "url": "https://oi-wiki.org/"},
+    {"title": "cppreference C++14", "url": "https://en.cppreference.com/w/cpp/14"},
+    {
+        "title": "GCC Warning Options",
+        "url": "https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html",
+    },
+    {"title": "洛谷（题解与训练）", "url": "https://www.luogu.com.cn/"},
+]
+
+
+@dataclass
+class LlmResult:
+    ok: bool
+    feedback_md: str
+    links: List[Dict[str, str]]
+    model_name: str
+    status: str
+
+
+def env(name: str, default: str = "") -> str:
+    value = os.getenv(name, "").strip()
+    return value if value else default
+
+
+def load_input(path: str) -> Dict[str, Any]:
+    with open(path, "r", encoding="utf-8") as f:
+        data = json.load(f)
+    if not isinstance(data, dict):
+        raise ValueError("input json must be object")
+    return data
+
+
+def detect_cpp14_risk(code: str, compile_log: str) -> List[str]:
+    hints: List[str] = []
+    joined = f"{code}\n{compile_log}"
+    checks = [
+        (r"\bif\s+constexpr\b", "检测到 `if constexpr`（C++17），C++14 环境会 CE。"),
+        (r"\bstd::optional\b", "检测到 `std::optional`（C++17），建议改为普通变量+标记位。"),
+        (r"\bstd::variant\b", "检测到 `std::variant`（C++17），建议改为 struct/enum 分支。"),
+        (r"\bstd::string_view\b", "检测到 `std::string_view`（C++17），建议改为 `const string&`。"),
+        (r"\[[^\]]+\]\s*=" , "检测到结构化绑定迹象，C++14 不支持，建议改 pair/struct 访问。"),
+        (r"%I64d", "检测到 `%I64d`，Linux 评测机应统一使用 `%lld`。"),
+        (r"\bvoid\s+main\s*\(", "检测到 `void main()`，需改为 `int main()` 并 `return 0;`。"),
+    ]
+    for pattern, tip in checks:
+        if re.search(pattern, joined):
+            hints.append(tip)
+    if "-Wsign-compare" in compile_log:
+        hints.append("存在 `-Wsign-compare`，建议统一使用 `size_t` 或显式类型转换。")
+    return hints
+
+
+def build_fallback_feedback(payload: Dict[str, Any], llm_error: str = "") -> LlmResult:
+    status = str(payload.get("status", "Unknown"))
+    score = payload.get("score", 0)
+    compile_log = str(payload.get("compile_log", ""))
+    runtime_log = str(payload.get("runtime_log", ""))
+    code = str(payload.get("code", ""))
+
+    risk_tips = detect_cpp14_risk(code, compile_log)
+    if not risk_tips:
+        risk_tips = [
+            "请确认只使用 C++14 语法，避免 C++17 特性导致 CE。",
+            "若题目要求文件输入输出，使用 `freopen(\"xxx.in\",\"r\",stdin)` / `freopen(\"xxx.out\",\"w\",stdout)`。",
+        ]
+
+    thought = (
+        "代码通过了当前评测，核心思路基本正确，建议继续做规范化和鲁棒性收敛。"
+        if status.upper() == "AC"
+        else "当前提交未稳定通过，建议先按日志定位错误，再拆分为思路问题与实现问题逐步修复。"
+    )
+
+    lines: List[str] = []
+    lines.append("### 评测结论")
+    lines.append(f"- 本次状态：**{status}**，分数：**{score}**。")
+    lines.append(f"- 思路评价：{thought}")
+    lines.append("")
+    lines.append("### 福建 CSP-J/S 规范检查（C++14）")
+    for tip in risk_tips:
+        lines.append(f"- {tip}")
+    if compile_log.strip():
+        lines.append("- 编译日志有信息，建议逐条清理 warning，减少考场不确定性。")
+    if runtime_log.strip():
+        lines.append("- 运行日志有输出，建议重点检查边界输入与数组越界风险。")
+    lines.append("")
+    lines.append("### 修改建议（可执行）")
+    lines.append("- 按“先编译通过→再保证正确→最后做优化”的顺序迭代。")
+    lines.append("- `long long` 读写统一 `%lld`；不要使用 `%I64d`。")
+    lines.append("- 清理 signed/unsigned 警告，降低不同编译器行为差异。")
+    lines.append("- 确保 `int main()` 且 `return 0;`。")
+    lines.append("")
+    lines.append("### 知识点评测")
+    lines.append("- 强项：基础实现与调试流程。")
+    lines.append("- 待加强：边界构造、类型一致性、赛场环境兼容性。")
+    lines.append("")
+    lines.append("### 推荐外链资料")
+    for item in DEFAULT_LINKS:
+        lines.append(f"- [{item['title']}]({item['url']})")
+
+    if llm_error:
+        lines.append("")
+        lines.append(f"> 说明：LLM 调用失败，已返回规则兜底建议。错误：{llm_error}")
+
+    return LlmResult(
+        ok=True,
+        feedback_md="\n".join(lines).strip(),
+        links=DEFAULT_LINKS,
+        model_name="fallback-rules",
+        status="fallback",
+    )
+
+
+def normalize_links(raw: Any) -> List[Dict[str, str]]:
+    links: List[Dict[str, str]] = []
+    if isinstance(raw, list):
+        for item in raw:
+            if not isinstance(item, dict):
+                continue
+            title = str(item.get("title", "")).strip()
+            url = str(item.get("url", "")).strip()
+            if title and url:
+                links.append({"title": title, "url": url})
+    return links if links else DEFAULT_LINKS
+
+
+def dict_to_markdown(data: Dict[str, Any]) -> str:
+    parts: List[str] = []
+    for key, value in data.items():
+        title = str(key).strip() or "分析项"
+        if isinstance(value, str):
+            body = value.strip()
+        else:
+            body = json.dumps(value, ensure_ascii=False, indent=2)
+        if not body:
+            continue
+        parts.append(f"### {title}\n{body}")
+    return "\n\n".join(parts)
+
+
+def call_llm(payload: Dict[str, Any]) -> LlmResult:
+    api_url = env("OI_LLM_API_URL") or env("CSP_LLM_API_URL")
+    api_key = env("OI_LLM_API_KEY") or env("CSP_LLM_API_KEY")
+    model = env("OI_LLM_MODEL", "qwen3-max")
+    if not api_url:
+        raise RuntimeError("missing OI_LLM_API_URL")
+
+    system_prompt = (
+        "你是福建省 CSP-J/S 代码规范与评测老师。"
+        "请严格按 C++14 旧 GCC 环境给建议，重点指出会导致 CE/RE/爆零的风险。"
+        "输出 JSON，不要输出其他文字。"
+    )
+    user_prompt = {
+        "task": "分析这份提交并给出改进建议",
+        "required_sections": [
+            "评测结论",
+            "福建 CSP-J/S 规范检查（C++14）",
+            "修改建议",
+            "知识点评测",
+            "推荐外链资料",
+        ],
+        "submission": payload,
+        "output_json_schema": {
+            "feedback_md": "markdown string",
+            "links": [{"title": "string", "url": "string"}],
+            "status": "ready",
+        },
+    }
+
+    headers = {"Content-Type": "application/json"}
+    if api_key:
+        headers["Authorization"] = f"Bearer {api_key}"
+
+    body = {
+        "model": model,
+        "stream": False,
+        "temperature": 0.1,
+        "messages": [
+            {"role": "system", "content": system_prompt},
+            {"role": "user", "content": json.dumps(user_prompt, ensure_ascii=False)},
+        ],
+    }
+
+    resp = requests.post(api_url, headers=headers, json=body, timeout=50)
+    resp.raise_for_status()
+    data = resp.json()
+
+    choices = data.get("choices") if isinstance(data, dict) else None
+    if not choices:
+        raise RuntimeError("LLM response missing choices")
+    first = choices[0] if isinstance(choices, list) and choices else {}
+    message = first.get("message") if isinstance(first, dict) else {}
+    content = message.get("content", "") if isinstance(message, dict) else ""
+    if not isinstance(content, str) or not content.strip():
+        raise RuntimeError("LLM content is empty")
+
+    model_name = str(data.get("model", model)) if isinstance(data, dict) else model
+
+    parsed: Optional[Dict[str, Any]] = None
+    try:
+        candidate = json.loads(content)
+        if isinstance(candidate, dict):
+            parsed = candidate
+    except Exception:
+        parsed = None
+
+    if parsed and parsed.get("feedback_md"):
+        return LlmResult(
+            ok=True,
+            feedback_md=str(parsed.get("feedback_md", "")).strip(),
+            links=normalize_links(parsed.get("links")),
+            model_name=model_name,
+            status=str(parsed.get("status", "ready")) or "ready",
+        )
+
+    if parsed:
+        return LlmResult(
+            ok=True,
+            feedback_md=dict_to_markdown(parsed),
+            links=DEFAULT_LINKS,
+            model_name=model_name,
+            status="ready",
+        )
+
+    return LlmResult(
+        ok=True,
+        feedback_md=content.strip(),
+        links=DEFAULT_LINKS,
+        model_name=model_name,
+        status="ready",
+    )
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Analyze one submission with LLM + fallback")
+    parser.add_argument("--input-file", required=True, help="JSON file from backend")
+    args = parser.parse_args()
+
+    payload = load_input(args.input_file)
+    try:
+        result = call_llm(payload)
+    except Exception as exc:
+        result = build_fallback_feedback(payload, str(exc))
+
+    output = {
+        "feedback_md": result.feedback_md,
+        "links": result.links,
+        "model_name": result.model_name,
+        "status": result.status,
+    }
+    sys.stdout.write(json.dumps(output, ensure_ascii=False))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/generate_problem_solutions.py

@@ -7,7 +7,10 @@ import argparse
 import json
 import os
 import re
+import shutil
 import sqlite3
+import subprocess
+import tempfile
 import time
 from dataclasses import dataclass
 from typing import Any
@@ -15,6 +18,37 @@ from typing import Any
 import requests
 
 RETRYABLE_HTTP_CODES = {500, 502, 503, 504}
+CLANG_FORMAT_BIN = shutil.which("clang-format")
+GXX_BIN = shutil.which("g++")
+PLACEHOLDER_CODE_MARKERS = (
+    "todo",
+    "to do",
+    "请根据题意补全",
+    "待补全",
+    "自行补全",
+    "省略",
+    "your code here",
+)
+CPP17_BANNED_PATTERNS: tuple[tuple[re.Pattern[str], str], ...] = (
+    (re.compile(r"\bif\s+constexpr\b"), "if constexpr"),
+    (re.compile(r"\bstd::optional\b"), "std::optional"),
+    (re.compile(r"\bstd::variant\b"), "std::variant"),
+    (re.compile(r"\bstd::any\b"), "std::any"),
+    (re.compile(r"\bstd::string_view\b"), "std::string_view"),
+    (re.compile(r"\bstd::filesystem\b"), "std::filesystem"),
+    (re.compile(r"\bstd::byte\b"), "std::byte"),
+    (re.compile(r"\bstd::clamp\s*\("), "std::clamp"),
+    (re.compile(r"\bstd::gcd\s*\("), "std::gcd"),
+    (re.compile(r"\bstd::lcm\s*\("), "std::lcm"),
+    (re.compile(r"#\s*include\s*<\s*(optional|variant|any|string_view|filesystem|charconv|execution)\s*>"), "C++17 header"),
+    (
+        re.compile(
+            r"\b(?:const\s+)?auto(?:\s*&|\s*&&)?\s*\[[^\]\n]+\]\s*=",
+            flags=re.MULTILINE,
+        ),
+        "structured bindings",
+    ),
+)
 
 
 @dataclass
@@ -32,6 +66,17 @@ def now_sec() -> int:
     return int(time.time())
 
 
+def env_bool(key: str, default: bool) -> bool:
+    raw = os.getenv(key, "").strip().lower()
+    if not raw:
+        return default
+    if raw in {"1", "true", "yes", "on"}:
+        return True
+    if raw in {"0", "false", "no", "off"}:
+        return False
+    return default
+
+
 def extract_json_object(text: str) -> dict[str, Any] | None:
     raw = text.strip()
     if raw.startswith("```"):
@@ -54,6 +99,253 @@ def extract_json_object(text: str) -> dict[str, Any] | None:
         return None
 
 
+def extract_message_text(content: Any) -> str:
+    if isinstance(content, str):
+        return content.strip()
+    if isinstance(content, list):
+        parts: list[str] = []
+        for item in content:
+            if isinstance(item, dict):
+                text = item.get("text")
+                if isinstance(text, str) and text.strip():
+                    parts.append(text.strip())
+                    continue
+                nested = item.get("content")
+                if isinstance(nested, str) and nested.strip():
+                    parts.append(nested.strip())
+        return "\n".join(parts).strip()
+    if isinstance(content, dict):
+        text = content.get("text")
+        if isinstance(text, str):
+            return text.strip()
+        nested = content.get("content")
+        if isinstance(nested, str):
+            return nested.strip()
+    return ""
+
+
+def iter_json_candidates(text: str) -> list[str]:
+    if not text:
+        return []
+    raw = text.strip()
+    candidates: list[str] = [raw] if raw else []
+
+    for match in re.finditer(r"```(?:json)?\s*([\s\S]*?)```", text, flags=re.IGNORECASE):
+        block = match.group(1).strip()
+        if block:
+            candidates.append(block)
+
+    decoder = json.JSONDecoder()
+    limit = min(len(text), 200000)
+    sample = text[:limit]
+    for idx, ch in enumerate(sample):
+        if ch not in "{[":
+            continue
+        try:
+            _, end = decoder.raw_decode(sample[idx:])
+        except json.JSONDecodeError:
+            continue
+        snippet = sample[idx : idx + end].strip()
+        if snippet:
+            candidates.append(snippet)
+
+    seen: set[str] = set()
+    deduped: list[str] = []
+    for cand in candidates:
+        if cand in seen:
+            continue
+        seen.add(cand)
+        deduped.append(cand)
+    return deduped
+
+
+def extract_solution_rows(content: str) -> list[dict[str, Any]]:
+    for candidate in iter_json_candidates(content):
+        try:
+            parsed = json.loads(candidate)
+        except json.JSONDecodeError:
+            continue
+
+        rows: Any = None
+        if isinstance(parsed, dict):
+            rows = parsed.get("solutions")
+            if rows is None and isinstance(parsed.get("data"), dict):
+                rows = parsed["data"].get("solutions")
+        elif isinstance(parsed, list):
+            rows = parsed
+
+        if isinstance(rows, list):
+            filtered = [x for x in rows if isinstance(x, dict)]
+            if filtered:
+                return filtered
+    return []
+
+
+def is_placeholder_code(code: str) -> bool:
+    lower = (code or "").lower()
+    if any(marker in lower for marker in PLACEHOLDER_CODE_MARKERS):
+        return True
+    if "..." in code:
+        return True
+    return False
+
+
+def cpp14_violations(code: str) -> list[str]:
+    hits: list[str] = []
+    for pattern, label in CPP17_BANNED_PATTERNS:
+        if pattern.search(code):
+            hits.append(label)
+    return hits
+
+
+def compiles_under_cpp14(code: str) -> tuple[bool, str]:
+    if not GXX_BIN:
+        return True, ""
+    with tempfile.TemporaryDirectory(prefix="csp_sol_cpp14_") as tmp:
+        src_path = os.path.join(tmp, "main.cpp")
+        with open(src_path, "w", encoding="utf-8") as f:
+            f.write(code if code.endswith("\n") else f"{code}\n")
+        proc = subprocess.run(
+            [GXX_BIN, "-std=gnu++14", "-O2", "-Wall", "-Wextra", "-Wpedantic", "-fsyntax-only", src_path],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            check=False,
+            timeout=12,
+        )
+        if proc.returncode == 0:
+            return True, ""
+        err = proc.stderr.decode("utf-8", errors="ignore").strip()
+        return False, err[:400]
+
+
+def normalize_solutions(rows: list[dict[str, Any]], max_solutions: int) -> tuple[list[dict[str, Any]], list[str]]:
+    normalized: list[dict[str, Any]] = []
+    rejected: list[str] = []
+    for row in rows:
+        title = str(row.get("title") or "").strip()
+        idea_md = str(row.get("idea_md") or "").strip()
+        explanation_md = str(row.get("explanation_md") or "").strip()
+        complexity = str(row.get("complexity") or "").strip()
+        code_cpp = str(row.get("code_cpp") or "")
+        tags = row.get("tags") if isinstance(row.get("tags"), list) else []
+
+        if not code_cpp.strip():
+            rejected.append("empty code_cpp")
+            continue
+        if "main(" not in code_cpp:
+            rejected.append("missing main()")
+            continue
+        if is_placeholder_code(code_cpp):
+            rejected.append("placeholder code")
+            continue
+        violations = cpp14_violations(code_cpp)
+        if violations:
+            rejected.append(f"C++17+ feature: {', '.join(violations[:3])}")
+            continue
+        ok_cpp14, compile_msg = compiles_under_cpp14(code_cpp)
+        if not ok_cpp14:
+            rejected.append(f"cannot compile with -std=gnu++14: {compile_msg}")
+            continue
+
+        normalized.append(
+            {
+                "title": title,
+                "idea_md": idea_md,
+                "explanation_md": explanation_md,
+                "complexity": complexity,
+                "code_cpp": code_cpp,
+                "tags": tags,
+            }
+        )
+        if len(normalized) >= max_solutions:
+            break
+    return normalized, rejected
+
+
+def build_prompt(problem: Problem, max_solutions: int) -> str:
+    return f"""
+请为下面这道 CSP 题生成 {max_solutions} 种不同思路的题解（可从模拟/贪心/DP/图论/数据结构等不同角度切入），并给出可直接提交的 C++14 参考代码。
+
+硬性要求：
+1. 必须只输出一个 JSON 对象，不能有任何 JSON 外文本。
+2. JSON 必须符合下面格式，且 solutions 数组长度应为 {max_solutions}。
+3. 每个 code_cpp 必须是完整、可编译、可运行的 C++14 程序（包含 main 函数），不能出现 TODO、伪代码、占位注释、省略号。
+4. 必须兼容 GCC 4.9/5.4 + -std=gnu++14：严禁使用 C++17 及以上特性（如 structured bindings、if constexpr、std::optional、std::variant、std::any、std::string_view、<filesystem>）。
+5. 建议使用标准头文件（如 <iostream>/<vector>/<algorithm> 等），不要使用 <bits/stdc++.h>。
+6. main 必须是 int main()，并且 return 0;。若使用 scanf/printf 处理 long long，格式符必须用 %lld，不要用 %I64d。
+7. 代码风格清晰，变量命名可读，注释简洁。
+
+输出 JSON，格式固定：
+{{
+  "solutions": [
+    {{
+      "title": "解法标题",
+      "idea_md": "思路要点（Markdown）",
+      "explanation_md": "详细讲解（Markdown）",
+      "complexity": "时间/空间复杂度",
+      "code_cpp": "完整 C++14 代码",
+      "tags": ["标签1","标签2"]
+    }}
+  ]
+}}
+
+题目信息：
+- 题目：{problem.title}
+- 难度：{problem.difficulty}
+- 来源：{problem.source}
+
+完整题面（原文，不做截断）：
+{problem.statement_md}
+
+样例输入（原文）：
+{problem.sample_input}
+
+样例输出（原文）：
+{problem.sample_output}
+""".strip()
+
+
+def parse_solutions_or_raise(content: str, max_solutions: int) -> list[dict[str, Any]]:
+    rows = extract_solution_rows(content)
+    if not rows:
+        raise RuntimeError("llm response missing valid solutions array")
+    normalized, rejected = normalize_solutions(rows, max_solutions=max_solutions)
+    if not normalized:
+        reason = f"; rejected sample: {rejected[0][:180]}" if rejected else ""
+        raise RuntimeError(f"llm response contains no runnable full code{reason}")
+    return normalized
+
+
+def generate_solutions_with_llm(
+    prompt: str,
+    max_solutions: int,
+    timeout: int,
+    retries: int,
+    sleep_sec: float,
+) -> list[dict[str, Any]]:
+    first_content = llm_request(prompt, timeout=timeout, retries=retries, sleep_sec=sleep_sec)
+    try:
+        return parse_solutions_or_raise(first_content, max_solutions=max_solutions)
+    except Exception as first_exc:
+        repair_prompt = (
+            "你上一条回复不符合要求，原因是："
+            f"{str(first_exc)[:240]}。请只输出合法 JSON，并确保 code_cpp 是完整可运行 C++14 代码（兼容 -std=gnu++14）。\n\n"
+            + prompt
+        )
+        second_content = llm_request(
+            repair_prompt,
+            timeout=timeout,
+            retries=retries,
+            sleep_sec=sleep_sec,
+        )
+        try:
+            return parse_solutions_or_raise(second_content, max_solutions=max_solutions)
+        except Exception as second_exc:
+            raise RuntimeError(
+                f"parse failed after retry: first={str(first_exc)[:200]}; second={str(second_exc)[:200]}"
+            ) from second_exc
+
+
 def llm_request(prompt: str, timeout: int, retries: int, sleep_sec: float) -> str:
     url = os.getenv("OI_LLM_API_URL", "").strip()
     api_key = os.getenv("OI_LLM_API_KEY", "").strip()
@@ -102,10 +394,14 @@ def llm_request(prompt: str, timeout: int, retries: int, sleep_sec: float) -> st
         choices = payload.get("choices") or []
         if not choices:
             raise RuntimeError("llm response missing choices")
-        content = ((choices[0] or {}).get("message") or {}).get("content")
+        choice0 = choices[0] or {}
+        message = choice0.get("message") or {}
+        content = extract_message_text(message.get("content"))
+        if not content:
+            content = extract_message_text(choice0.get("text"))
         if not content:
             raise RuntimeError("llm response missing content")
-        return str(content)
+        return content
 
     if last_error:
         raise RuntimeError(f"llm request failed: {last_error}") from last_error
@@ -119,7 +415,20 @@ def fallback_solutions(max_solutions: int) -> list[dict[str, Any]]:
             "idea_md": "按题意拆分步骤，先写可过样例的直观解法，再补边界处理。",
             "explanation_md": "适用于数据范围较小或规则清晰的题。",
             "complexity": "时间复杂度依题而定，通常 O(n)~O(n^2)",
-            "code_cpp": "// TODO: 请根据题意补全\n#include <bits/stdc++.h>\nusing namespace std;\nint main(){ios::sync_with_stdio(false);cin.tie(nullptr);return 0;}\n",
+            "code_cpp": """
+#include <iostream>
+#include <vector>
+#include <algorithm>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    // TODO: 请根据题意补全读入、核心逻辑与输出。
+    return 0;
+}
+""".strip(),
             "tags": ["simulation", "implementation"],
         },
         {
@@ -127,13 +436,55 @@ def fallback_solutions(max_solutions: int) -> list[dict[str, Any]]:
             "idea_md": "分析状态与重复计算，尝试用前缀和、贪心或动态规划优化。",
             "explanation_md": "比直接模拟更稳定，通常能覆盖更大数据规模。",
             "complexity": "通常优于朴素解法",
-            "code_cpp": "// TODO: 请根据题意补全\n#include <bits/stdc++.h>\nusing namespace std;\nint main(){ios::sync_with_stdio(false);cin.tie(nullptr);return 0;}\n",
+            "code_cpp": """
+#include <iostream>
+#include <vector>
+#include <algorithm>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    // TODO: 请根据题意补全优化版思路实现。
+    return 0;
+}
+""".strip(),
             "tags": ["optimization", "dp"],
         },
     ]
     return base[: max(1, max_solutions)]
 
 
+def format_cpp_code(raw: str) -> str:
+    code = (raw or "").replace("\r\n", "\n").replace("\r", "\n")
+    if not code.strip():
+        return ""
+    if not code.endswith("\n"):
+        code += "\n"
+
+    if not CLANG_FORMAT_BIN:
+        return code
+
+    try:
+        proc = subprocess.run(
+            [CLANG_FORMAT_BIN, "--style={BasedOnStyle: Google, IndentWidth: 2, ColumnLimit: 0}"],
+            input=code.encode("utf-8"),
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            check=False,
+            timeout=6,
+        )
+        if proc.returncode == 0 and proc.stdout:
+            out = proc.stdout.decode("utf-8", errors="ignore")
+            if out.strip():
+                return out if out.endswith("\n") else f"{out}\n"
+    except Exception:
+        pass
+
+    return code
+
+
 def load_problem(conn: sqlite3.Connection, problem_id: int) -> Problem:
     cur = conn.execute(
         "SELECT id,title,statement_md,difficulty,source,sample_input,sample_output FROM problems WHERE id=?",
@@ -182,7 +533,7 @@ def store_solutions(conn: sqlite3.Connection, problem_id: int, rows: list[dict[s
 
         idea_md = str(row.get("idea_md") or "").strip()
         explanation_md = str(row.get("explanation_md") or "").strip()
-        code_cpp = str(row.get("code_cpp") or "").strip()
+        code_cpp = format_cpp_code(str(row.get("code_cpp") or ""))
         complexity = str(row.get("complexity") or "").strip()
         tags = row.get("tags") if isinstance(row.get("tags"), list) else []
 
@@ -239,68 +590,41 @@ def main() -> int:
 
     try:
         problem = load_problem(conn, args.problem_id)
+        requested_solutions = max(1, min(5, args.max_solutions))
+        allow_fallback = env_bool("CSP_SOLUTION_ALLOW_FALLBACK", False)
 
-        prompt = f"""
-请为下面这道 CSP 题生成 {max(1, min(5, args.max_solutions))} 种不同思路的题解（可从不同角度切入，例如模拟/贪心/DP/数据结构），并给出 C++ 参考代码。
-
-输出 JSON，格式固定：
-{{
-  "solutions": [
-    {{
-      "title": "解法标题",
-      "idea_md": "思路要点（Markdown）",
-      "explanation_md": "详细讲解（Markdown）",
-      "complexity": "时间/空间复杂度",
-      "code_cpp": "完整 C++17 代码",
-      "tags": ["标签1","标签2"]
-    }}
-  ]
-}}
-
-题目：{problem.title}
-难度：{problem.difficulty}
-来源：{problem.source}
-题面：
-{problem.statement_md[:12000]}
-样例输入：
-{problem.sample_input[:1200]}
-样例输出：
-{problem.sample_output[:1200]}
-""".strip()
+        prompt = build_prompt(problem, max_solutions=requested_solutions)
 
         update_job(conn, args.job_id, progress=25, message="requesting llm", updated_at=now_sec())
 
-        source = "fallback"
+        source = "llm"
         solutions: list[dict[str, Any]]
         try:
-            content = llm_request(
-                prompt,
+            solutions = generate_solutions_with_llm(
+                prompt=prompt,
+                max_solutions=requested_solutions,
                 timeout=args.timeout,
                 retries=args.retries,
                 sleep_sec=args.retry_sleep_sec,
             )
-            obj = extract_json_object(content)
-            raw = obj.get("solutions") if isinstance(obj, dict) else None
-            if not isinstance(raw, list) or len(raw) == 0:
-                raise RuntimeError("llm response missing solutions array")
-            solutions = [x for x in raw if isinstance(x, dict)]
-            if not solutions:
-                raise RuntimeError("llm response has empty valid solutions")
-            source = "llm"
-        except Exception:
+        except Exception as exc:
+            if not allow_fallback:
+                raise RuntimeError(f"llm generation failed: {str(exc)[:280]}") from exc
+            source = "fallback"
             solutions = fallback_solutions(args.max_solutions)
 
-        solutions = solutions[: max(1, min(5, args.max_solutions))]
+        solutions = solutions[:requested_solutions]
 
         update_job(conn, args.job_id, progress=70, message="writing solutions", updated_at=now_sec())
         saved = store_solutions(conn, args.problem_id, solutions, source)
 
+        done_msg = f"completed: {saved} solutions ({source})"
         update_job(
             conn,
             args.job_id,
             status="completed",
             progress=100,
-            message=f"completed: {saved} solutions ({source})",
+            message=done_msg,
             finished_at=now_sec(),
             updated_at=now_sec(),
         )

scripts/import_kb_learning_resources.py

@@ -0,0 +1,487 @@
+#!/usr/bin/env python3
+"""Collect C++/CSP learning resources from the web, summarize with LLM, and upsert KB articles."""
+
+from __future__ import annotations
+
+import argparse
+import html
+import json
+import os
+import re
+import sqlite3
+import sys
+import time
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+import requests
+
+RETRYABLE_HTTP_CODES = {429, 500, 502, 503, 504}
+DEFAULT_TIMEOUT = 30
+USER_AGENT = (
+    "Mozilla/5.0 (X11; Linux x86_64) "
+    "AppleWebKit/537.36 (KHTML, like Gecko) "
+    "Chrome/123.0.0.0 Safari/537.36"
+)
+NO_PROXY = {"http": "", "https": ""}
+
+
+@dataclass(frozen=True)
+class ResourceSource:
+    label: str
+    url: str
+
+
+@dataclass(frozen=True)
+class TrackSpec:
+    slug: str
+    title: str
+    audience: str
+    objective: str
+    sources: tuple[ResourceSource, ...]
+
+
+TRACKS: tuple[TrackSpec, ...] = (
+    TrackSpec(
+        slug="learning-roadmap-csp",
+        title="CSP 学习总路线（C++ 基础 → CSP-J → CSP-S）",
+        audience="准备长期学习 CSP 的初中/高中选手与家长",
+        objective="给出分阶段目标、周训练节奏、升阶检查清单和环境规范提醒。",
+        sources=(
+            ResourceSource("NOI 技术规则", "https://www.noi.cn/gynoi/jsgz/"),
+            ResourceSource(
+                "NOI Linux 与说明文档下载",
+                "https://www.noi.cn/gynoi/jsgz/2018-08-21/710467.shtml",
+            ),
+            ResourceSource(
+                "NOI 标准竞赛环境说明（2012）",
+                "https://www.noi.cn/gynoi/jsgz/2018-08-13/710466.shtml",
+            ),
+            ResourceSource("OI Wiki 竞赛路线图", "https://oi-wiki.org/contest/roadmap/"),
+            ResourceSource("OI Wiki 竞赛资源", "https://oi-wiki.org/contest/resources/"),
+            ResourceSource(
+                "cp-algorithms 首页",
+                "https://cp-algorithms.com/",
+            ),
+        ),
+    ),
+    TrackSpec(
+        slug="learning-cpp-basic",
+        title="C++ 基础学习资料（面向 CSP）",
+        audience="C++ 零基础或语法不稳，准备进入 CSP-J 的同学",
+        objective="梳理语法基础、STL 入门、输入输出与 C++14 兼容写法。",
+        sources=(
+            ResourceSource("cppreference C++ language", "https://en.cppreference.com/w/cpp/language.html"),
+            ResourceSource("OI Wiki 语言基础", "https://oi-wiki.org/lang/basic/"),
+            ResourceSource("OI Wiki 数组", "https://oi-wiki.org/lang/array/"),
+            ResourceSource("OI Wiki 循环", "https://oi-wiki.org/lang/loop/"),
+            ResourceSource("OI Wiki 运算符", "https://oi-wiki.org/lang/op/"),
+            ResourceSource("OI Wiki C++ 标准库", "https://oi-wiki.org/lang/csl/"),
+            ResourceSource("OI Wiki 文件操作", "https://oi-wiki.org/lang/file-op/"),
+        ),
+    ),
+    TrackSpec(
+        slug="learning-csp-j",
+        title="CSP-J 学习资料与训练路径",
+        audience="目标 CSP-J 提高组入门，正在建立算法基础的同学",
+        objective="覆盖模拟、枚举、前缀和、基础搜索与基础 DP，给出循序刷题方案。",
+        sources=(
+            ResourceSource("NOI 技术规则", "https://www.noi.cn/gynoi/jsgz/"),
+            ResourceSource("OI Wiki 模拟", "https://oi-wiki.org/basic/simulate/"),
+            ResourceSource("OI Wiki 枚举", "https://oi-wiki.org/basic/enumerate/"),
+            ResourceSource("OI Wiki 前缀和与差分", "https://oi-wiki.org/basic/prefix-sum/"),
+            ResourceSource("OI Wiki 动态规划基础", "https://oi-wiki.org/dp/basic/"),
+            ResourceSource("OI Wiki BFS", "https://oi-wiki.org/search/bfs/"),
+            ResourceSource("OI Wiki DFS", "https://oi-wiki.org/search/dfs/"),
+            ResourceSource("OI Wiki 常见错误", "https://oi-wiki.org/contest/common-mistakes/"),
+        ),
+    ),
+    TrackSpec(
+        slug="learning-csp-s",
+        title="CSP-S 学习资料与进阶路径",
+        audience="目标 CSP-S，已具备 CSP-J 基础并准备系统进阶的同学",
+        objective="覆盖数据结构、图论、字符串与 DP 进阶，强调复杂度与工程规范。",
+        sources=(
+            ResourceSource(
+                "NOI 标准竞赛环境说明（2016）",
+                "https://www.noi.cn/gynoi/jsgz/2018-08-13/710465.shtml",
+            ),
+            ResourceSource(
+                "NOI 标准竞赛环境说明（2012）",
+                "https://www.noi.cn/gynoi/jsgz/2018-08-13/710466.shtml",
+            ),
+            ResourceSource("OI Wiki 树状数组", "https://oi-wiki.org/ds/fenwick/"),
+            ResourceSource("OI Wiki 线段树", "https://oi-wiki.org/ds/seg/"),
+            ResourceSource("OI Wiki 最短路", "https://oi-wiki.org/graph/shortest-path/"),
+            ResourceSource("OI Wiki 强连通分量", "https://oi-wiki.org/graph/scc/"),
+            ResourceSource("OI Wiki 最大流", "https://oi-wiki.org/graph/flow/max-flow/"),
+            ResourceSource("OI Wiki 树上 DP", "https://oi-wiki.org/dp/tree/"),
+            ResourceSource("OI Wiki KMP", "https://oi-wiki.org/string/kmp/"),
+            ResourceSource(
+                "cp-algorithms Segment Tree",
+                "https://cp-algorithms.com/data_structures/segment_tree.html",
+            ),
+        ),
+    ),
+)
+
+
+def now_sec() -> int:
+    return int(time.time())
+
+
+def load_dotenv(path: Path) -> None:
+    if not path.exists():
+        return
+    for raw in path.read_text(encoding="utf-8", errors="ignore").splitlines():
+        line = raw.strip()
+        if not line or line.startswith("#") or "=" not in line:
+            continue
+        key, value = line.split("=", 1)
+        key = key.strip()
+        if not key or key in os.environ:
+            continue
+        os.environ[key] = value.strip().strip("\"").strip("'")
+
+
+def fetch_url(url: str, timeout: int) -> tuple[str, str]:
+    headers = {"User-Agent": USER_AGENT}
+    resp = requests.get(url, headers=headers, timeout=timeout, proxies=NO_PROXY)
+    resp.encoding = resp.apparent_encoding or resp.encoding
+    if resp.status_code >= 400:
+        raise RuntimeError(f"HTTP {resp.status_code}")
+    html_text = resp.text
+    return html_text, resp.url
+
+
+def strip_html(html_text: str, max_chars: int) -> str:
+    text = re.sub(r"(?is)<(script|style|noscript|svg|canvas)[^>]*>.*?</\\1>", " ", html_text)
+    text = re.sub(r"(?is)<br\\s*/?>", "\n", text)
+    text = re.sub(r"(?is)</(p|div|section|article|h1|h2|h3|h4|h5|h6|li|tr|table|ul|ol)>", "\n", text)
+    text = re.sub(r"(?is)<[^>]+>", " ", text)
+    text = html.unescape(text)
+    text = text.replace("\r", "\n").replace("\xa0", " ")
+    text = re.sub(r"[ \t\f\v]+", " ", text)
+    text = re.sub(r"\n{3,}", "\n\n", text)
+    text = "\n".join(line.strip() for line in text.splitlines() if line.strip())
+    if len(text) > max_chars:
+        text = text[:max_chars].rstrip() + "\n..."
+    return text
+
+
+def extract_title(html_text: str, fallback: str) -> str:
+    match = re.search(r"(?is)<title>(.*?)</title>", html_text)
+    if not match:
+        return fallback
+    title = html.unescape(match.group(1))
+    title = re.sub(r"\s+", " ", title).strip()
+    if title:
+        return title
+    return fallback
+
+
+def extract_message_text(content: Any) -> str:
+    if isinstance(content, str):
+        return content.strip()
+    if isinstance(content, list):
+        out: list[str] = []
+        for item in content:
+            if isinstance(item, dict):
+                text = item.get("text")
+                if isinstance(text, str) and text.strip():
+                    out.append(text.strip())
+        return "\n".join(out).strip()
+    if isinstance(content, dict):
+        text = content.get("text")
+        if isinstance(text, str):
+            return text.strip()
+    return ""
+
+
+def llm_request(prompt: str, timeout: int, retries: int, retry_sleep_sec: float) -> str:
+    url = os.getenv("OI_LLM_API_URL", "").strip()
+    api_key = os.getenv("OI_LLM_API_KEY", "").strip()
+    model = os.getenv("OI_LLM_MODEL", "qwen3-max").strip()
+    if not url:
+        raise RuntimeError("missing OI_LLM_API_URL")
+
+    headers = {"Content-Type": "application/json"}
+    if api_key:
+        headers["Authorization"] = f"Bearer {api_key}"
+
+    payload = {
+        "model": model,
+        "stream": False,
+        "temperature": 0.2,
+        "messages": [
+            {
+                "role": "system",
+                "content": "你是资深信息学竞赛教练，请严格基于来源内容整理中文 Markdown 学习资料。",
+            },
+            {"role": "user", "content": prompt},
+        ],
+    }
+
+    for idx in range(1, retries + 1):
+        try:
+            resp = requests.post(url, headers=headers, json=payload, timeout=timeout, proxies=NO_PROXY)
+        except requests.RequestException as exc:
+            if idx >= retries:
+                raise RuntimeError(f"llm request failed: {exc}") from exc
+            time.sleep(retry_sleep_sec * idx)
+            continue
+
+        if resp.status_code in RETRYABLE_HTTP_CODES:
+            if idx >= retries:
+                raise RuntimeError(f"llm retry exhausted: HTTP {resp.status_code}")
+            time.sleep(retry_sleep_sec * idx)
+            continue
+
+        if resp.status_code >= 400:
+            raise RuntimeError(f"llm request failed: HTTP {resp.status_code}: {resp.text[:300]}")
+
+        body = resp.json()
+        choices = body.get("choices") or []
+        if not choices:
+            raise RuntimeError("llm response missing choices")
+        message = (choices[0] or {}).get("message") or {}
+        text = extract_message_text(message.get("content"))
+        if not text:
+            text = extract_message_text((choices[0] or {}).get("text"))
+        if not text:
+            raise RuntimeError("llm response missing content")
+        return text
+
+    raise RuntimeError("llm request failed")
+
+
+def remove_outer_markdown_fence(text: str) -> str:
+    raw = text.strip()
+    match = re.match(r"^```(?:markdown|md)?\\s*([\\s\\S]*?)\\s*```$", raw, flags=re.IGNORECASE)
+    if match:
+        return match.group(1).strip()
+    return raw
+
+
+def build_prompt(spec: TrackSpec, source_materials: list[dict[str, str]]) -> str:
+    source_lines = "\n".join([f"- {it['label']}: {it['url']}" for it in source_materials])
+    snippets: list[str] = []
+    for idx, item in enumerate(source_materials, start=1):
+        snippets.append(
+            "\n".join(
+                [
+                    f"[来源 {idx}] {item['label']}",
+                    f"URL: {item['url']}",
+                    f"页面标题: {item['title']}",
+                    "摘录:",
+                    item["snippet"],
+                ]
+            )
+        )
+
+    all_snippets = "\n\n".join(snippets)
+
+    return f"""
+请整理一篇中文 Markdown 学习资料文章，主题：{spec.title}
+
+目标读者：{spec.audience}
+目标：{spec.objective}
+
+硬性要求：
+1. 只输出 Markdown 正文，不要输出解释、前言、JSON 或代码块外的多余说明。
+2. 正文不少于 900 字，内容要具体可执行，不能只给提纲。
+3. 内容结构至少包含：
+   - 学习目标
+   - 知识图谱（按优先级）
+   - 分阶段训练计划（建议按周）
+   - 常见失分点与避坑清单
+   - C++14 / 评测环境规范提醒（明确写出：优先 C++14；避免 C++17 特性；long long 用 %lld；如赛方要求则使用 freopen；main 返回 int 且 return 0）
+4. 结尾必须包含“## 参考来源”章节，并且只列出本次给定来源，使用 Markdown 链接。
+5. 不要编造具体年份政策细节；对于地方性要求，写“以当年官方通知为准”。
+6. 风格要可执行，尽量给出检查清单与训练顺序。
+
+可用来源列表：
+{source_lines}
+
+来源摘录：
+{all_snippets}
+""".strip()
+
+
+def fallback_markdown(spec: TrackSpec, source_materials: list[dict[str, str]], error_text: str) -> str:
+    lines = [
+        f"# {spec.title}",
+        "",
+        "## 学习目标",
+        f"- 读者：{spec.audience}",
+        f"- 目标：{spec.objective}",
+        "",
+        "## 训练建议",
+        "- 每周固定做 3~5 道题：先基础题，再专项题，再限时套题。",
+        "- 每次训练后补齐错因：读题失误、边界遗漏、复杂度超限、代码规范错误。",
+        "- 建议建立个人模板并反复演练输入输出与边界处理。",
+        "",
+        "## C++14 / 评测环境规范提醒",
+        "- 统一按 C++14 编译，避免 C++17 及以上语法。",
+        "- `long long` 输入输出优先使用 `%lld`。",
+        "- 若赛方要求文件读写，使用 `freopen(\"xxx.in\", \"r\", stdin)` / `freopen(\"xxx.out\", \"w\", stdout)`。",
+        "- `main` 必须是 `int main()` 且 `return 0;`。",
+        "- 地方考区细则每年会更新，务必以当年官方通知为准。",
+        "",
+        "## 参考来源",
+    ]
+    for item in source_materials:
+        lines.append(f"- [{item['label']}]({item['url']})")
+    lines.extend(
+        [
+            "",
+            "> 说明：本条目由自动整理流程生成。",
+            f"> LLM 调用失败原因：{error_text[:180]}",
+        ]
+    )
+    return "\n".join(lines).strip() + "\n"
+
+
+def upsert_article(conn: sqlite3.Connection, slug: str, title: str, content_md: str, ts: int) -> None:
+    conn.execute(
+        """
+        INSERT INTO kb_articles(slug, title, content_md, created_at)
+        VALUES(?, ?, ?, ?)
+        ON CONFLICT(slug) DO UPDATE SET
+          title=excluded.title,
+          content_md=excluded.content_md,
+          created_at=excluded.created_at
+        """,
+        (slug, title, content_md, ts),
+    )
+
+
+def guess_db_path(cli_path: str | None) -> str:
+    if cli_path:
+        return cli_path
+    candidates = [
+        os.getenv("CSP_DB_PATH", "").strip(),
+        "/data/csp.db",
+        "/var/lib/docker/volumes/csp_csp_data/_data/csp.db",
+        str(Path(__file__).resolve().parents[1] / "data" / "csp.db"),
+    ]
+    for path in candidates:
+        if path and Path(path).exists():
+            return path
+    return "/data/csp.db"
+
+
+def collect_source_materials(
+    spec: TrackSpec,
+    timeout: int,
+    max_chars_per_source: int,
+    max_sources_per_track: int,
+) -> list[dict[str, str]]:
+    materials: list[dict[str, str]] = []
+    for src in spec.sources[:max_sources_per_track]:
+        try:
+            html_text, final_url = fetch_url(src.url, timeout=timeout)
+            title = extract_title(html_text, src.label)
+            if "404" in title.lower() and "not found" in title.lower():
+                raise RuntimeError(f"unexpected 404 title: {title}")
+            snippet = strip_html(html_text, max_chars=max_chars_per_source)
+            if not snippet:
+                raise RuntimeError("empty extracted text")
+            materials.append(
+                {
+                    "label": src.label,
+                    "url": final_url,
+                    "title": title,
+                    "snippet": snippet,
+                }
+            )
+            print(f"[fetch] ok: {spec.slug} <- {src.url}")
+        except Exception as exc:
+            print(f"[fetch] skip: {spec.slug} <- {src.url} ({exc})", file=sys.stderr)
+
+    if not materials:
+        raise RuntimeError(f"no source material collected for {spec.slug}")
+    return materials
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Import web learning resources into kb_articles")
+    parser.add_argument("--db-path", default="", help="SQLite path (default: auto-detect)")
+    parser.add_argument("--timeout", type=int, default=DEFAULT_TIMEOUT)
+    parser.add_argument("--retries", type=int, default=5)
+    parser.add_argument("--retry-sleep-sec", type=float, default=1.5)
+    parser.add_argument("--max-chars-per-source", type=int, default=900)
+    parser.add_argument("--max-sources-per-track", type=int, default=3)
+    parser.add_argument("--dry-run", action="store_true")
+    parser.add_argument(
+        "--only",
+        default="",
+        help="Only process one track slug, e.g. learning-csp-j",
+    )
+    args = parser.parse_args()
+
+    repo_root = Path(__file__).resolve().parents[1]
+    load_dotenv(repo_root / ".env")
+
+    db_path = guess_db_path(args.db_path or None)
+    print(f"[db] using: {db_path}")
+
+    conn = sqlite3.connect(db_path)
+    conn.execute("PRAGMA foreign_keys=ON")
+    conn.execute("PRAGMA busy_timeout=10000")
+
+    processed = 0
+    for spec in TRACKS:
+        if args.only and spec.slug != args.only.strip():
+            continue
+
+        print(f"[track] start: {spec.slug}")
+        materials = collect_source_materials(
+            spec,
+            timeout=max(5, args.timeout),
+            max_chars_per_source=max(600, args.max_chars_per_source),
+            max_sources_per_track=max(1, args.max_sources_per_track),
+        )
+
+        prompt = build_prompt(spec, materials)
+        markdown: str
+        try:
+            markdown = llm_request(
+                prompt=prompt,
+                timeout=max(15, args.timeout * 2),
+                retries=max(1, args.retries),
+                retry_sleep_sec=max(0.2, args.retry_sleep_sec),
+            )
+            markdown = remove_outer_markdown_fence(markdown)
+            if os.getenv("KB_IMPORT_DEBUG", "").strip():
+                preview = markdown.strip().replace("\n", "\\n")
+                print(
+                    f"[llm] raw: {spec.slug} len={len(markdown.strip())} preview={preview[:220]}",
+                    file=sys.stderr,
+                )
+            if len(markdown.strip()) < 120:
+                raise RuntimeError("llm output too short")
+            print(f"[llm] ok: {spec.slug}")
+        except Exception as exc:
+            print(f"[llm] fallback: {spec.slug} ({exc})", file=sys.stderr)
+            markdown = fallback_markdown(spec, materials, str(exc))
+
+        content = markdown.strip() + "\n"
+        if args.dry_run:
+            print(f"[dry-run] {spec.slug}: {len(content)} chars")
+            processed += 1
+            continue
+
+        upsert_article(conn, spec.slug, spec.title, content, now_sec())
+        conn.commit()
+        processed += 1
+        print(f"[db] upserted: {spec.slug}")
+
+    conn.close()
+    print(f"[done] processed tracks: {processed}")
+    return 0 if processed > 0 else 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())