diff --git a/AGENTS.md b/AGENTS.md
new file mode 100644
index 0000000..6a28e8b
--- /dev/null
+++ b/AGENTS.md
@@ -0,0 +1,28 @@
+# Repository Guidelines
+
+## Project Structure & Module Organization
+
+This is a Vue 3 and Express quiz application about Dart and Flutter; it is not a Flutter SDK project. The Express API and production static server live in `server.js`. The Vue client is under `web/`: views belong in `web/src/views/`, shared browser utilities in `web/src/`, and global styles in `web/src/styles/theme.css`. `questions.json` is the application database, while `scripts/data/` contains import sources and `scripts/` contains maintenance utilities. Vite writes production assets to the generated, ignored `dist/` directory. Root `index.html` is a legacy artifact; the active entry is `web/index.html`.
+
+## Build, Test, and Development Commands
+
+- `npm install` installs the pinned dependencies from `package-lock.json`.
+- `npm run dev` starts Express and Vite together; browse via Vite at `http://localhost:5173`.
+- `npm run build` bundles `web/` into `dist/`.
+- `npm start` serves the built client and API on `PORT` (default `3031`).
+- `node scripts/verify-questions.js` validates question fields, answer indexes, explanations, and difficulty values.
+- `node scripts/fix-escaping.js` normalizes stored HTML escaping in place; restart the server afterward.
+
+Keep `vite.config.js`'s `/api` proxy aligned with the Express `PORT` when changing local ports.
+
+## Coding Style & Naming Conventions
+
+Use two-space indentation. Follow existing JavaScript style: CommonJS in `server.js` and `scripts/`, ES modules and Vue `<script setup>` in `web/`. Name Vue components and views in PascalCase (`QuizView.vue`), functions and variables in camelCase, and CSS classes in kebab-case. Reuse tokens and shared classes from `theme.css`; keep view-only CSS scoped. UI text, comments, and API errors should remain Simplified Chinese. Preserve the escaping contract in `web/src/htmlUtil.mjs` for authored HTML.
+
+## Testing Guidelines
+
+No unit-test framework or coverage threshold is configured. Before submitting, run `npm run build` and `node scripts/verify-questions.js`. Manually exercise quiz selection, offline answer grading, admin login, and question CRUD when those paths change. Never edit `questions.json` while the server is running: the next API write can overwrite external changes.
+
+## Commit & Pull Request Guidelines
+
+Recent history favors short, imperative Conventional Commit subjects such as `chore: change default port to 3031`; use `feat:`, `fix:`, `chore:`, or `docs:` with a focused description. Keep commits single-purpose. Pull requests should explain behavior and data-shape changes, list verification commands, link relevant issues, and include screenshots for visible UI changes. Document new environment variables and avoid committing `.env`, credentials, `node_modules/`, or `dist/`. Replace the default admin credentials in deployed environments.
diff --git a/CLAUDE.md b/CLAUDE.md
index 33c0a84..cd4fbfd 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -12,12 +12,12 @@ All UI copy, comments, and API error messages are Simplified Chinese. Keep new s
 
 ```bash
 npm install
-npm run dev      # concurrently: Express on :3030 + Vite dev server on :5173 — develop at http://localhost:5173
+npm run dev      # concurrently: Express on :3031 + Vite dev server on :5173 — develop at http://localhost:5173
 npm run build    # Vite builds web/ → dist/ at the repo root
-npm start        # Express only on :3030, serving dist/ + API (requires a prior build)
+npm start        # Express only on :3031, serving dist/ + API (requires a prior build)
 ```
 
-Server env vars (defaults in parens): `PORT` (3030), `ADMIN_USER` (admin), `ADMIN_PASS` (admin123).
+Server env vars (defaults in parens): `PORT` (3031), `ADMIN_USER` (admin), `ADMIN_PASS` (admin123).
 
 ### Data scripts
 
@@ -26,7 +26,7 @@ No test runner is configured. `verify-questions.js` is the closest thing to a te
 ```bash
 node scripts/verify-questions.js  # structural validation of every question + hardcoded answer-index spot checks
 node scripts/fix-escaping.js      # re-normalizes HTML escaping across questions.json in place; also asserts the transform is idempotent
-node scripts/import-sets.js [file...]  # POSTs scripts/data/<file> into an ALREADY-RUNNING server on :3030 (logs in as admin/admin123); with no args, re-imports the two original dev sets
+node scripts/import-sets.js [file...]  # POSTs scripts/data/<file> into an ALREADY-RUNNING server on :3031; BASE_URL/ADMIN_USER/ADMIN_PASS can override connection settings
 node scripts/extract-questions.js # DESTRUCTIVE one-shot legacy migration; see "Legacy files" below
 ```
 
@@ -36,11 +36,11 @@ node scripts/extract-questions.js # DESTRUCTIVE one-shot legacy migration; see "
 
 ### Two processes, one origin
 
-The frontend never hardcodes an API host — `web/src/api.js` always fetches `/api/...`. In dev, Vite's proxy (`vite.config.js`) forwards `/api` to `:3030`. In production, Express serves `dist/` and the API from the same port, with a catch-all (`/^\/(?!api\/).*/`) sending everything non-`/api` to `index.html`. Preserve that same-origin assumption when adding endpoints.
+The frontend never hardcodes an API host — `web/src/api.js` always fetches `/api/...`. In dev, Vite's proxy (`vite.config.js`) forwards `/api` to `:3031`. In production, Express serves `dist/` and the API from the same port, with a catch-all (`/^\/(?!api\/).*/`) sending everything non-`/api` to `index.html`. Preserve that same-origin assumption when adding endpoints.
 
 ### Data store: one JSON file, held in memory
 
-`questions.json` at the repo root is the entire database. `server.js` reads it **once at boot** into a module-level `data` object; every mutating route calls `saveData()`, which rewrites the whole file synchronously.
+`questions.json` at the repo root is the entire database. `server.js` reads and validates it **once at boot** into a module-level `data` object; every mutating route calls `saveData()`, which writes a temporary file and atomically replaces the database.
 
 Consequences to keep in mind:
 - Hand-editing `questions.json` while the server is running will be silently clobbered by the next write. Restart after external edits (including after running `fix-escaping.js`).
@@ -54,21 +54,23 @@ Consequences to keep in mind:
 
 `GET /api/questions` returns whole questions through `toPublic()`, **including `ans` and `exp`**. That is deliberate: `QuizView` caches the full set in `localStorage` and grades locally, so answering keeps working with the network down — and because grading is synchronous, a correct pick renders green immediately instead of flashing red while a round trip completes. The trade-off is that answers are visible in the network payload; don't reintroduce answer-stripping without also rethinking offline grading. `toPublic()` is still an explicit whitelist, so new internal fields (authoring notes, review flags) stay server-side unless you add them there.
 
-Caching is **network-first, cache-fallback** in both `loadSets()` and `loadQuestions()`: an online client always gets fresh questions, so edits made in the admin UI are never masked by a stale cache and no invalidation mechanism is needed. Keys are versioned (`quiz-cache-v1-sets`, `quiz-cache-v1-set-<id>`) — bump `CACHE_VER` in `QuizView.vue` when the payload shape changes. Answer progress is intentionally *not* persisted: a reload restarts the round.
+Caching is **network-first, cache-fallback** in both `loadSets()` and `loadQuestions()`: an online client always gets fresh questions, so edits made in the admin UI are never masked by a stale cache. Keys are versioned (`quiz-cache-v2-sets`, `quiz-cache-v2-set-<id>`) — bump `CACHE_VER` in `QuizView.vue` when the payload shape changes. Answer progress is persisted per set and restored only when the server-provided content `version` still matches.
 
 `loadQuestions()` bails out with a visible error if the first question has no `ans`, which catches the dev-mode trap of editing `server.js` without restarting it (`npm run dev` runs Express and Vite as separate processes) — otherwise local grading would silently mark every answer wrong.
 
-`POST /api/check` still exists and still grades server-side, but the quiz page no longer calls it. `GET /api/admin/sets` returns full questions and stays behind auth.
+`POST /api/check` still exists and still grades server-side, but the quiz page no longer calls it. `GET /api/admin/sets` returns lightweight summaries; fetch one set and its questions from `GET /api/admin/sets/:id`.
+
+New and duplicated sets are drafts (`published: false`). Public endpoints only expose sets that are published and contain at least one question. Use `PATCH /api/admin/sets/:id/publish` to publish or unpublish; deleting the last question automatically returns a set to draft state.
 
 ### Auth
 
-`POST /api/admin/login` compares against the env credentials and returns a random hex token stored in an in-memory `Set`. Tokens have no expiry but are lost on restart, so a server restart logs every admin out. The client keeps the token in `localStorage` under `quiz_token` and sends it as `Authorization: Bearer`; `AdminView.checkAuth()` validates it by probing `/admin/sets` on mount.
+`POST /api/admin/login` compares against the env credentials and returns a random hex token stored in an in-memory `Set`. Tokens have no expiry but are lost on restart, so a server restart logs every admin out. The client keeps the token in `localStorage` under `quiz_token` and sends it as `Authorization: Bearer`; `AdminView` loads `/admin/sets` once on mount to validate the token and bootstrap the list.
 
 ### HTML escaping contract
 
 `web/src/htmlUtil.mjs` is shared by the browser bundle and the Node scripts — that is why it is `.mjs` (CommonJS scripts `await import()` it). Don't rename it to `.js`.
 
-`escapeSmartHtml()` preserves an allowlist of formatting tags (`b`, `code`, `pre`, lists, headings, …) and escapes everything else, so question authors can paste raw `<` and `>` from code samples without hand-writing `&lt;`. Stored content in `questions.json` is therefore already-escaped HTML.
+`escapeSmartHtml()` preserves an allowlist of formatting tags (`b`, `code`, `pre`, lists, headings, …), strips all tag attributes, and escapes everything else, so question authors can paste raw `<` and `>` from code samples without hand-writing `&lt;`. The server applies the same attribute-free allowlist when questions are created, imported, or updated. Stored content in `questions.json` is therefore already-escaped HTML.
 
 The round trip in `AdminView` is: `decodeEntities()` when loading into the editor → edit as plain text → `escapeSmartHtml(decodeEntities(...))` on save. This is deliberately idempotent, and `fix-escaping.js` verifies that property. Keep any new field that accepts authored markup on the same path.
 
diff --git a/scripts/import-sets.js b/scripts/import-sets.js
index bea42d2..c34e774 100644
--- a/scripts/import-sets.js
+++ b/scripts/import-sets.js
@@ -1,7 +1,9 @@
 const fs = require('fs');
 const path = require('path');
 
-const BASE = 'http://localhost:3030';
+const BASE = (process.env.BASE_URL || 'http://localhost:3031').replace(/\/$/, '');
+const ADMIN_USER = process.env.ADMIN_USER || 'admin';
+const ADMIN_PASS = process.env.ADMIN_PASS || 'admin123';
 const ARGS = process.argv.slice(2);
 const FILES = ARGS.length ? ARGS : ['set-dart-dev.json', 'set-flutter-dev.json'];
 
@@ -9,7 +11,7 @@ async function main() {
   const loginRes = await fetch(BASE + '/api/admin/login', {
     method: 'POST',
     headers: { 'Content-Type': 'application/json' },
-    body: JSON.stringify({ username: 'admin', password: 'admin123' })
+    body: JSON.stringify({ username: ADMIN_USER, password: ADMIN_PASS })
   });
   const login = await loginRes.json();
   if (!loginRes.ok) throw new Error('登录失败: ' + login.error);
diff --git a/scripts/verify-questions.js b/scripts/verify-questions.js
index 293c809..105243b 100644
--- a/scripts/verify-questions.js
+++ b/scripts/verify-questions.js
@@ -1,18 +1,46 @@
 const d = require('../questions.json');
 let total = 0, bad = [];
+const setIds = new Set(), qIds = new Set(), setNames = new Set();
+let maxSetId = 0, maxQId = 0;
+if (!d || !Array.isArray(d.sets)) {
+  console.error('questions.json 根节点必须包含 sets 数组');
+  process.exit(1);
+}
 for (const set of d.sets) {
+  if (!Number.isInteger(set.id) || set.id < 1 || setIds.has(set.id)) bad.push(`[套题] ID 非法或重复: ${set.id}`);
+  else { setIds.add(set.id); maxSetId = Math.max(maxSetId, set.id); }
+  const normalizedName = typeof set.name === 'string' ? set.name.trim().toLowerCase() : '';
+  if (!normalizedName || setNames.has(normalizedName)) bad.push(`[套题 #${set.id}] 名称为空或重复`);
+  else setNames.add(normalizedName);
+  if (typeof set.name === 'string' && set.name.trim().length > 80) bad.push(`[套题 #${set.id}] 名称超过 80 个字符`);
+  if (set.description !== undefined && (typeof set.description !== 'string' || set.description.trim().length > 240)) {
+    bad.push(`[${set.name || set.id}] description 必须为不超过 240 字的字符串`);
+  }
+  if (set.published !== undefined && typeof set.published !== 'boolean') bad.push(`[${set.name || set.id}] published 必须为布尔值`);
+  if (!Array.isArray(set.questions)) { bad.push(`[${set.name || set.id}] questions 不是数组`); continue; }
+  if (set.lvNames != null && (!Array.isArray(set.lvNames) || set.lvNames.length !== 6 || set.lvNames.some(n => typeof n !== 'string' || !n.trim()))) {
+    bad.push(`[${set.name}] lvNames 必须为 6 个非空名称`);
+  }
   for (const q of set.questions) {
     total++;
-    if (!q.q || !Array.isArray(q.opts) || q.opts.length < 2) { bad.push(`[${set.name} #${q.id}] 选项不足`); continue; }
+    if (!Number.isInteger(q.id) || q.id < 1 || qIds.has(q.id)) { bad.push(`[${set.name}] 题目 ID 非法或重复: ${q.id}`); continue; }
+    qIds.add(q.id); maxQId = Math.max(maxQId, q.id);
+    if (typeof q.q !== 'string' || !q.q.trim()) { bad.push(`[${set.name} #${q.id}] 题干必须为非空字符串`); continue; }
+    if (!Array.isArray(q.opts) || q.opts.length < 2 || q.opts.some(o => typeof o !== 'string' || !o.trim())) {
+      bad.push(`[${set.name} #${q.id}] 至少需要 2 个非空字符串选项`); continue;
+    }
     if (!Number.isInteger(q.ans) || q.ans < 0 || q.ans >= q.opts.length) { bad.push(`[${set.name} #${q.id}] ans 越界`); continue; }
-    if (!q.exp) { bad.push(`[${set.name} #${q.id}] 缺解析`); continue; }
+    if (typeof q.exp !== 'string' || !q.exp.trim()) { bad.push(`[${set.name} #${q.id}] 解析必须为非空字符串`); continue; }
     if (!Number.isInteger(q.lv) || q.lv < 1 || q.lv > 6) { bad.push(`[${set.name} #${q.id}] lv 非法`); continue; }
-    const dup = q.opts.findIndex((o, i) => q.opts.indexOf(o) !== i);
+    const normalizedOpts = q.opts.map(o => o.trim());
+    const dup = normalizedOpts.findIndex((o, i) => normalizedOpts.indexOf(o) !== i);
     if (dup !== -1) { bad.push(`[${set.name} #${q.id}] 选项重复: "${q.opts[dup]}"`); }
   }
 }
+if (!Number.isInteger(d.nextSetId) || d.nextSetId <= maxSetId) bad.push(`nextSetId 应大于 ${maxSetId}`);
+if (!Number.isInteger(d.nextQId) || d.nextQId <= maxQId) bad.push(`nextQId 应大于 ${maxQId}`);
 console.log('总题数:', total);
-if (bad.length) { console.log('问题:'); bad.forEach(b => console.log(' -', b)); }
+if (bad.length) { console.log('问题:'); bad.forEach(b => console.log(' -', b)); process.exitCode = 1; }
 else console.log('结构校验全部通过');
 
 // 抽查逻辑已移除，因为选项顺序已被随机打乱
diff --git a/server.js b/server.js
index ae1e098..e16c7fa 100644
--- a/server.js
+++ b/server.js
@@ -7,6 +7,14 @@ const PORT = process.env.PORT || 3031;
 const ADMIN_USER = process.env.ADMIN_USER || 'admin';
 const ADMIN_PASS = process.env.ADMIN_PASS || 'admin123';
 const DATA_FILE = path.join(__dirname, 'questions.json');
+const MAX_SET_NAME = 80;
+const MAX_SET_DESCRIPTION = 240;
+const SAFE_HTML_TAGS = new Set([
+  'b', 'strong', 'i', 'em', 'code', 'br', 'span', 'div', 'p',
+  'ul', 'ol', 'li', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6',
+  'blockquote', 'pre', 'u', 's', 'mark', 'small', 'sub', 'sup'
+]);
+const SAFE_TAG_RE = /<\/?([a-zA-Z][a-zA-Z0-9]*)>/g;
 
 const app = express();
 app.use(express.json({ limit: '2mb' }));
@@ -24,28 +32,87 @@ if (fs.existsSync(DIST)) {
 function loadData() {
   if (!fs.existsSync(DATA_FILE)) return { sets: [], nextSetId: 1, nextQId: 1 };
   try {
-    const raw = JSON.parse(fs.readFileSync(DATA_FILE, 'utf8'));
+    let raw = JSON.parse(fs.readFileSync(DATA_FILE, 'utf8'));
+    let migratedFromArray = false;
     if (Array.isArray(raw)) {
-      const qs = raw;
-      const migrated = {
-        sets: [{ id: 1, name: 'Dart & Flutter 学习测验', questions: qs }],
+      raw = {
+        sets: [{ id: 1, name: 'Dart & Flutter 学习测验', questions: raw }],
         nextSetId: 2,
-        nextQId: qs.length ? Math.max(...qs.map(q => q.id)) + 1 : 1
+        nextQId: 1
       };
-      fs.writeFileSync(DATA_FILE, JSON.stringify(migrated, null, 2), 'utf8');
-      return migrated;
+      migratedFromArray = true;
     }
-    if (raw && Array.isArray(raw.sets)) return raw;
-    return { sets: [], nextSetId: 1, nextQId: 1 };
-  } catch {
-    return { sets: [], nextSetId: 1, nextQId: 1 };
+    if (!raw || !Array.isArray(raw.sets)) throw new Error('根节点必须包含 sets 数组');
+
+    const setIds = new Set();
+    const questionIds = new Set();
+    const setNames = new Set();
+    let maxSetId = 0;
+    let maxQId = 0;
+    for (const set of raw.sets) {
+      if (!Number.isInteger(set.id) || set.id < 1 || setIds.has(set.id)) throw new Error('套题 ID 缺失、非法或重复');
+      if (!set.name || typeof set.name !== 'string' || !Array.isArray(set.questions)) throw new Error(`套题 #${set.id} 结构不完整`);
+      const normalizedName = set.name.trim().toLowerCase();
+      if (!normalizedName) throw new Error(`套题 #${set.id} 的名称不能为空`);
+      if (setNames.has(normalizedName)) throw new Error(`套题名称重复：${set.name}`);
+      if (set.description !== undefined && typeof set.description !== 'string') throw new Error(`套题 #${set.id} 的简介必须为字符串`);
+      if (set.published !== undefined && typeof set.published !== 'boolean') throw new Error(`套题 #${set.id} 的 published 必须为布尔值`);
+      if (set.published === undefined) set.published = set.questions.length > 0;
+      if (!set.questions.length) set.published = false;
+      const lvErr = validateLvNames(set.lvNames);
+      if (lvErr) throw new Error(`套题 #${set.id}：${lvErr}`);
+      setIds.add(set.id);
+      setNames.add(normalizedName);
+      maxSetId = Math.max(maxSetId, set.id);
+      for (const q of set.questions) {
+        if (!Number.isInteger(q.id) || q.id < 1 || questionIds.has(q.id)) throw new Error('题目 ID 缺失、非法或重复');
+        const questionErr = validateBody(q);
+        if (questionErr) throw new Error(`套题 #${set.id} 的题目 #${q.id}：${questionErr}`);
+        questionIds.add(q.id);
+        maxQId = Math.max(maxQId, q.id);
+      }
+    }
+    raw.nextSetId = Math.max(Number.isInteger(raw.nextSetId) ? raw.nextSetId : 1, maxSetId + 1);
+    raw.nextQId = Math.max(Number.isInteger(raw.nextQId) ? raw.nextQId : 1, maxQId + 1);
+    if (migratedFromArray) {
+      const tempFile = DATA_FILE + '.tmp';
+      try {
+        fs.writeFileSync(tempFile, JSON.stringify(raw, null, 2), 'utf8');
+        fs.renameSync(tempFile, DATA_FILE);
+      } finally {
+        if (fs.existsSync(tempFile)) fs.unlinkSync(tempFile);
+      }
+    }
+    return raw;
+  } catch (err) {
+    throw new Error(`无法加载 questions.json：${err.message}`);
   }
 }
 
 const data = loadData();
+let savedDataSnapshot = JSON.stringify(data);
 
 function saveData() {
-  fs.writeFileSync(DATA_FILE, JSON.stringify(data, null, 2), 'utf8');
+  const tempFile = DATA_FILE + '.tmp';
+  const serialized = JSON.stringify(data, null, 2);
+  try {
+    fs.writeFileSync(tempFile, serialized, 'utf8');
+    fs.renameSync(tempFile, DATA_FILE);
+    savedDataSnapshot = serialized;
+  } catch (err) {
+    // 路由会先修改内存再落盘。使用最近一次成功保存的内存快照回滚，
+    // 即使磁盘此时也不可读，失败操作也不会泄漏到后续请求。
+    const restored = JSON.parse(savedDataSnapshot);
+    for (const key of Object.keys(data)) delete data[key];
+    Object.assign(data, restored);
+    throw err;
+  } finally {
+    try {
+      if (fs.existsSync(tempFile)) fs.unlinkSync(tempFile);
+    } catch (cleanupErr) {
+      console.error('清理题库临时文件失败:', cleanupErr);
+    }
+  }
 }
 
 const tokens = new Set();
@@ -58,6 +125,73 @@ function findQuestion(qid) {
   return null;
 }
 
+function findSet(id) {
+  return data.sets.find(s => s.id === id) || null;
+}
+
+function isPublished(set) {
+  return set.published !== false && set.questions.length > 0;
+}
+
+function setVersion(set) {
+  return crypto.createHash('sha1')
+    .update(JSON.stringify({ lvNames: set.lvNames || null, questions: set.questions }))
+    .digest('hex')
+    .slice(0, 12);
+}
+
+function levelCounts(set) {
+  const counts = [0, 0, 0, 0, 0, 0];
+  for (const q of set.questions) {
+    if (Number.isInteger(q.lv) && q.lv >= 1 && q.lv <= 6) counts[q.lv - 1]++;
+  }
+  return counts;
+}
+
+function toSetSummary(set, admin = false) {
+  const summary = {
+    id: set.id,
+    name: set.name,
+    description: set.description || '',
+    count: set.questions.length,
+    lvNames: set.lvNames || null,
+    levelCounts: levelCounts(set),
+    version: setVersion(set)
+  };
+  if (admin) summary.published = isPublished(set);
+  return summary;
+}
+
+function validateSetFields(body, excludeId = null) {
+  const { name, description } = body || {};
+  if (!name || typeof name !== 'string' || name.trim() === '') return '套题名称不能为空';
+  if (name.trim().length > MAX_SET_NAME) return `套题名称不能超过 ${MAX_SET_NAME} 个字符`;
+  if (description !== undefined && typeof description !== 'string') return '套题简介必须为字符串';
+  if ((description || '').trim().length > MAX_SET_DESCRIPTION) return `套题简介不能超过 ${MAX_SET_DESCRIPTION} 个字符`;
+  if (data.sets.some(s => s.id !== excludeId && s.name.trim().toLowerCase() === name.trim().toLowerCase())) {
+    return '已存在同名套题';
+  }
+  return validateLvNames(body.lvNames);
+}
+
+function applySetFields(set, body) {
+  set.name = body.name.trim();
+  set.description = (body.description || '').trim();
+  if (body.lvNames === null) delete set.lvNames;
+  else if (body.lvNames !== undefined) set.lvNames = body.lvNames.map(x => x.trim());
+}
+
+function uniqueCopyName(name) {
+  const names = new Set(data.sets.map(s => s.name.trim().toLowerCase()));
+  let index = 1;
+  while (true) {
+    const suffix = index === 1 ? '（副本）' : `（副本 ${index}）`;
+    const candidate = name.slice(0, MAX_SET_NAME - suffix.length).trimEnd() + suffix;
+    if (!names.has(candidate.toLowerCase())) return candidate;
+    index++;
+  }
+}
+
 // 答题页需要整套缓存以支持离线判分，因此下发答案与解析。
 // 保留显式白名单：以后给题目加内部字段（如出题备注）不会顺手漏出去。
 function toPublic(q) {
@@ -69,14 +203,38 @@ function validateBody(body) {
   if (!q || typeof q !== 'string' || q.trim() === '') return '题目内容不能为空';
   if (!Array.isArray(opts) || opts.length < 2) return '至少需要 2 个选项';
   if (opts.some(o => typeof o !== 'string' || o.trim() === '')) return '选项不能为空';
+  const normalizedOpts = opts.map(o => o.trim());
+  if (new Set(normalizedOpts).size !== normalizedOpts.length) return '选项不能重复';
   if (typeof ans !== 'number' || !Number.isInteger(ans) || ans < 0 || ans >= opts.length) return '答案序号不正确';
   if (lv !== undefined && (!Number.isInteger(lv) || lv < 1 || lv > 6)) return '难度需为 1-6 的整数';
+  if (typeof exp !== 'string' || exp.trim() === '') return '答案解析不能为空';
   return null;
 }
 
+function sanitizeAuthoredHtml(html) {
+  const placeholders = [];
+  const text = String(html).replace(SAFE_TAG_RE, (match, tag) => {
+    const normalizedTag = tag.toLowerCase();
+    if (!SAFE_HTML_TAGS.has(normalizedTag)) return match;
+    placeholders.push(match.startsWith('</') ? `</${normalizedTag}>` : `<${normalizedTag}>`);
+    return `\u0000${placeholders.length - 1}\u0000`;
+  });
+  return text
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/\u0000(\d+)\u0000/g, (_, i) => placeholders[Number(i)]);
+}
+
 function buildQuestion(body) {
   const { lv, q, opts, ans, exp } = body;
-  return { id: data.nextQId++, lv: lv === undefined ? 1 : lv, q: q.trim(), opts, ans, exp: (exp || '').trim() };
+  return {
+    id: data.nextQId++,
+    lv: lv === undefined ? 1 : lv,
+    q: sanitizeAuthoredHtml(q.trim()),
+    opts: opts.map(o => o.trim()),
+    ans,
+    exp: sanitizeAuthoredHtml(exp.trim())
+  };
 }
 
 function validateLvNames(v) {
@@ -88,15 +246,18 @@ function validateLvNames(v) {
 }
 
 app.get('/api/sets', (req, res) => {
-  res.json({ sets: data.sets.map(s => ({ id: s.id, name: s.name, count: s.questions.length, lvNames: s.lvNames || null })) });
+  const sets = data.sets.filter(isPublished).map(s => toSetSummary(s));
+  res.json({ sets, total: sets.length });
 });
 
 app.get('/api/questions', (req, res) => {
-  const setId = req.query.set ? Number(req.query.set) : (data.sets[0] ? data.sets[0].id : null);
-  const set = data.sets.find(s => s.id === setId);
-  if (!set) return res.status(404).json({ error: '套题不存在' });
+  const publishedSets = data.sets.filter(isPublished);
+  const setId = req.query.set ? Number(req.query.set) : (publishedSets[0] ? publishedSets[0].id : null);
+  if (req.query.set && !Number.isInteger(setId)) return res.status(400).json({ error: '套题 ID 格式不正确' });
+  const set = publishedSets.find(s => s.id === setId);
+  if (!set) return res.status(404).json({ error: '套题不存在、尚未发布或暂无题目' });
   res.json({
-    set: { id: set.id, name: set.name, lvNames: set.lvNames || null },
+    set: toSetSummary(set),
     count: set.questions.length,
     questions: set.questions.map(toPublic)
   });
@@ -105,7 +266,7 @@ app.get('/api/questions', (req, res) => {
 app.post('/api/check', (req, res) => {
   const { id, answer } = req.body || {};
   const hit = findQuestion(id);
-  if (!hit) return res.status(404).json({ error: '题目不存在' });
+  if (!hit || !isPublished(hit.set)) return res.status(404).json({ error: '题目不存在' });
   if (!Number.isInteger(answer)) return res.status(400).json({ error: 'answer 必须为数字' });
   res.json({ correct: hit.q.ans === answer, answer: hit.q.ans, exp: hit.q.exp });
 });
@@ -128,59 +289,92 @@ function requireAuth(req, res, next) {
 }
 
 app.get('/api/admin/sets', requireAuth, (req, res) => {
-  res.json({ sets: data.sets });
+  res.json({ sets: data.sets.map(s => toSetSummary(s, true)) });
+});
+
+app.get('/api/admin/sets/:id', requireAuth, (req, res) => {
+  const set = findSet(Number(req.params.id));
+  if (!set) return res.status(404).json({ error: '套题不存在' });
+  res.json({ set: { ...toSetSummary(set, true), questions: set.questions } });
 });
 
 app.post('/api/admin/sets', requireAuth, (req, res) => {
-  const { name } = req.body || {};
-  if (!name || typeof name !== 'string' || name.trim() === '') return res.status(400).json({ error: '套题名称不能为空' });
-  const lvErr = validateLvNames(req.body.lvNames);
-  if (lvErr) return res.status(400).json({ error: lvErr });
-  const set = { id: data.nextSetId++, name: name.trim(), questions: [] };
-  if (req.body.lvNames !== undefined) set.lvNames = req.body.lvNames;
+  const err = validateSetFields(req.body);
+  if (err) return res.status(400).json({ error: err });
+  const set = { id: data.nextSetId++, name: '', description: '', published: false, questions: [] };
+  applySetFields(set, req.body);
   data.sets.push(set);
   saveData();
-  res.json(set);
+  res.status(201).json({ set: toSetSummary(set, true) });
 });
 
 app.put('/api/admin/sets/:id', requireAuth, (req, res) => {
   const id = Number(req.params.id);
-  const set = data.sets.find(s => s.id === id);
+  const set = findSet(id);
   if (!set) return res.status(404).json({ error: '套题不存在' });
-  const { name } = req.body || {};
-  if (!name || typeof name !== 'string' || name.trim() === '') return res.status(400).json({ error: '套题名称不能为空' });
-  const lvErr = validateLvNames(req.body.lvNames);
-  if (lvErr) return res.status(400).json({ error: lvErr });
-  set.name = name.trim();
-  if (req.body.lvNames !== undefined) set.lvNames = req.body.lvNames;
+  const err = validateSetFields(req.body, id);
+  if (err) return res.status(400).json({ error: err });
+  applySetFields(set, req.body);
   saveData();
-  res.json(set);
+  res.json({ set: toSetSummary(set, true) });
+});
+
+app.patch('/api/admin/sets/:id/publish', requireAuth, (req, res) => {
+  const set = findSet(Number(req.params.id));
+  if (!set) return res.status(404).json({ error: '套题不存在' });
+  if (typeof req.body?.published !== 'boolean') return res.status(400).json({ error: 'published 必须为布尔值' });
+  if (req.body.published && !set.questions.length) return res.status(400).json({ error: '空套题不能发布，请先添加题目' });
+  set.published = req.body.published;
+  saveData();
+  res.json({ set: toSetSummary(set, true) });
+});
+
+app.post('/api/admin/sets/:id/duplicate', requireAuth, (req, res) => {
+  const source = findSet(Number(req.params.id));
+  if (!source) return res.status(404).json({ error: '套题不存在' });
+  const copy = {
+    id: data.nextSetId++,
+    name: uniqueCopyName(source.name),
+    description: source.description || '',
+    published: false,
+    questions: source.questions.map(q => ({ ...q, id: data.nextQId++, opts: [...q.opts] }))
+  };
+  if (source.lvNames) copy.lvNames = [...source.lvNames];
+  data.sets.push(copy);
+  saveData();
+  res.status(201).json({ set: toSetSummary(copy, true) });
 });
 
 app.delete('/api/admin/sets/:id', requireAuth, (req, res) => {
   const id = Number(req.params.id);
   const idx = data.sets.findIndex(s => s.id === id);
   if (idx === -1) return res.status(404).json({ error: '套题不存在' });
+  const deleted = data.sets[idx];
   data.sets.splice(idx, 1);
   saveData();
-  res.json({ ok: true });
+  res.json({ ok: true, deleted: { id: deleted.id, name: deleted.name } });
 });
 
 app.post('/api/admin/import', requireAuth, (req, res) => {
-  const { name, questions } = req.body || {};
-  if (!name || typeof name !== 'string' || name.trim() === '') return res.status(400).json({ error: '套题名称不能为空' });
+  const { questions } = req.body || {};
+  const setErr = validateSetFields(req.body);
+  if (setErr) return res.status(400).json({ error: setErr });
   if (!Array.isArray(questions)) return res.status(400).json({ error: 'questions 必须为数组' });
-  const lvErr = validateLvNames(req.body.lvNames);
-  if (lvErr) return res.status(400).json({ error: lvErr });
   for (let i = 0; i < questions.length; i++) {
     const err = validateBody(questions[i]);
     if (err) return res.status(400).json({ error: '第 ' + (i + 1) + ' 题格式错误：' + err });
   }
-  const set = { id: data.nextSetId++, name: name.trim(), questions: questions.map(buildQuestion) };
-  if (req.body.lvNames !== undefined) set.lvNames = req.body.lvNames;
+  const set = {
+    id: data.nextSetId++,
+    name: '',
+    description: '',
+    published: questions.length > 0,
+    questions: questions.map(buildQuestion)
+  };
+  applySetFields(set, req.body);
   data.sets.push(set);
   saveData();
-  res.json({ set: { id: set.id, name: set.name, count: set.questions.length }, imported: set.questions.length });
+  res.status(201).json({ set: toSetSummary(set, true), imported: set.questions.length });
 });
 
 app.get('/api/admin/sets/:id/export', requireAuth, (req, res) => {
@@ -189,6 +383,7 @@ app.get('/api/admin/sets/:id/export', requireAuth, (req, res) => {
   if (!set) return res.status(404).json({ error: '套题不存在' });
   res.json({
     name: set.name,
+    description: set.description || '',
     lvNames: set.lvNames || null,
     exportedAt: new Date().toISOString(),
     questions: set.questions.map(q => ({ lv: q.lv, q: q.q, opts: q.opts, ans: q.ans, exp: q.exp }))
@@ -204,7 +399,7 @@ app.post('/api/admin/sets/:id/questions', requireAuth, (req, res) => {
   const item = buildQuestion(req.body);
   set.questions.push(item);
   saveData();
-  res.json(item);
+  res.status(201).json({ question: item, set: toSetSummary(set, true) });
 });
 
 app.put('/api/admin/questions/:qid', requireAuth, (req, res) => {
@@ -215,12 +410,12 @@ app.put('/api/admin/questions/:qid', requireAuth, (req, res) => {
   const { lv, q, opts, ans, exp } = req.body;
   const item = hit.q;
   item.lv = lv === undefined ? item.lv : lv;
-  item.q = q.trim();
-  item.opts = opts;
+  item.q = sanitizeAuthoredHtml(q.trim());
+  item.opts = opts.map(o => o.trim());
   item.ans = ans;
-  item.exp = (exp || '').trim();
+  item.exp = sanitizeAuthoredHtml(exp.trim());
   saveData();
-  res.json(item);
+  res.json({ question: item, set: toSetSummary(hit.set, true) });
 });
 
 app.delete('/api/admin/questions/:qid', requireAuth, (req, res) => {
@@ -228,13 +423,36 @@ app.delete('/api/admin/questions/:qid', requireAuth, (req, res) => {
   if (!hit) return res.status(404).json({ error: '题目不存在' });
   const idx = hit.set.questions.indexOf(hit.q);
   hit.set.questions.splice(idx, 1);
+  if (!hit.set.questions.length) hit.set.published = false;
   saveData();
-  res.json({ ok: true });
+  res.json({ ok: true, set: toSetSummary(hit.set, true) });
 });
 
-app.listen(PORT, '0.0.0.0', () => {
-  console.log('测验系统已启动: http://localhost:' + PORT);
-  console.log('答题页: http://localhost:' + PORT + '/');
-  console.log('管理后台: http://localhost:' + PORT + '/admin.html');
-  console.log('管理员账号: ' + ADMIN_USER + ' / ' + ADMIN_PASS);
+app.use('/api', (req, res) => {
+  res.status(404).json({ error: '接口不存在', code: 'NOT_FOUND' });
 });
+
+app.use((err, req, res, next) => {
+  if (res.headersSent) return next(err);
+  if (err.type === 'entity.parse.failed') {
+    return res.status(400).json({ error: '请求 JSON 格式不正确', code: 'INVALID_JSON' });
+  }
+  if (err.type === 'entity.too.large') {
+    return res.status(413).json({ error: '请求内容超过 2MB 限制', code: 'PAYLOAD_TOO_LARGE' });
+  }
+  console.error(err);
+  res.status(500).json({ error: '服务暂时不可用，请稍后重试', code: 'INTERNAL_ERROR' });
+});
+
+function startServer(port = PORT) {
+  return app.listen(port, '0.0.0.0', () => {
+    console.log('测验系统已启动: http://localhost:' + port);
+    console.log('答题页: http://localhost:' + port + '/');
+    console.log('管理后台: http://localhost:' + port + '/#/admin');
+    console.log('管理员账号: ' + ADMIN_USER + ' / ' + ADMIN_PASS);
+  });
+}
+
+if (require.main === module) startServer();
+
+module.exports = { app, startServer };
diff --git a/vite.config.js b/vite.config.js
index 7dc24f5..0ed57cb 100644
--- a/vite.config.js
+++ b/vite.config.js
@@ -11,7 +11,7 @@ export default defineConfig({
   server: {
     port: 5173,
     proxy: {
-      '/api': 'http://localhost:3030'
+      '/api': 'http://localhost:3031'
     }
   }
 })
diff --git a/web/src/api.js b/web/src/api.js
index 5ff7490..7954b72 100644
--- a/web/src/api.js
+++ b/web/src/api.js
@@ -12,23 +12,36 @@ export function clearToken() {
   localStorage.removeItem(TOKEN_KEY)
 }
 
-export async function api(path, options = {}) {
+async function request(path, options = {}, withAuth = false) {
   const headers = Object.assign({}, options.headers || {})
-  if (getToken()) headers.Authorization = 'Bearer ' + getToken()
+  const requestToken = withAuth ? getToken() : ''
+  if (requestToken) headers.Authorization = 'Bearer ' + requestToken
   if (options.body && !headers['Content-Type']) headers['Content-Type'] = 'application/json'
-  const res = await fetch('/api' + path, Object.assign({}, options, { headers }))
+  let res
+  try {
+    res = await fetch('/api' + path, Object.assign({}, options, { headers }))
+  } catch (cause) {
+    const err = new Error('无法连接服务器，请检查网络后重试')
+    err.cause = cause
+    throw err
+  }
   const data = await res.json().catch(() => ({}))
   if (!res.ok) {
     const err = new Error(data.error || '请求失败')
     err.status = res.status
+    err.code = data.code
+    // 只清除这次请求实际携带、且仍是当前值的 token；避免迟到的旧请求
+    // 把另一个标签页或并发登录刚写入的新会话误删。
+    if (withAuth && res.status === 401 && requestToken && getToken() === requestToken) clearToken()
     throw err
   }
   return data
 }
 
-export async function apiPublic(path, options = {}) {
-  const res = await fetch('/api' + path, options)
-  const data = await res.json().catch(() => ({}))
-  if (!res.ok) throw new Error(data.error || '请求失败')
-  return data
+export async function api(path, options = {}) {
+  return request(path, options, true)
+}
+
+export async function apiPublic(path, options = {}) {
+  return request(path, options, false)
 }
diff --git a/web/src/htmlUtil.mjs b/web/src/htmlUtil.mjs
index 20ed712..36b295a 100644
--- a/web/src/htmlUtil.mjs
+++ b/web/src/htmlUtil.mjs
@@ -9,8 +9,10 @@ const TAG_RE = /<\/?([a-zA-Z][a-zA-Z0-9]*)\b[^<>]*>/g
 export function escapeSmartHtml(html) {
   const placeholders = []
   const text = String(html).replace(TAG_RE, (m, tag) => {
-    if (ALLOWED_TAGS.includes(tag.toLowerCase())) {
-      placeholders.push(m)
+    const normalizedTag = tag.toLowerCase()
+    if (ALLOWED_TAGS.includes(normalizedTag)) {
+      // 只保留标签本身，不保留 onclick/style 等属性，避免 authored HTML 注入脚本或样式。
+      placeholders.push(m.startsWith('</') ? `</${normalizedTag}>` : `<${normalizedTag}>`)
       return '\u0000' + (placeholders.length - 1) + '\u0000'
     }
     return m
diff --git a/web/src/styles/theme.css b/web/src/styles/theme.css
index e302f07..b7ff457 100644
--- a/web/src/styles/theme.css
+++ b/web/src/styles/theme.css
@@ -105,6 +105,7 @@ body {
   padding: 7px 14px;
   border-radius: 999px;
   transition: all .2s;
+  white-space: nowrap;
 }
 
 .nav-link:hover { background: var(--surface-high); }
@@ -159,6 +160,15 @@ body {
 .btn:active { transform: scale(.97); }
 .btn:disabled { opacity: .45; cursor: not-allowed; }
 
+button:focus-visible,
+a:focus-visible,
+input:focus-visible,
+textarea:focus-visible,
+select:focus-visible {
+  outline: 3px solid rgba(61, 107, 94, .28);
+  outline-offset: 2px;
+}
+
 .btn-filled { background: var(--ink); color: var(--surface); }
 .btn-filled:hover:not(:disabled) { box-shadow: var(--shadow-lift); }
 
@@ -297,7 +307,12 @@ body {
 }
 
 @media (max-width: 640px) {
-  .app-header { padding: 20px 16px 12px; }
+  .app-header { padding: 18px 14px 12px; gap: 9px; }
+  .brand-seal { width: 40px; height: 40px; border-radius: 10px; font-size: 20px; }
   .card { padding: 20px; border-radius: 20px; }
-  .brand-name { font-size: 18px; }
+  .brand-name { font-size: 18px; letter-spacing: 1px; }
+  .brand-sub { font-size: 9px; letter-spacing: 1.5px; white-space: nowrap; }
+  .app-nav { gap: 0; }
+  .nav-link { padding: 6px 8px; font-size: 12px; }
+  .app-main { padding: 8px 14px 32px; }
 }
diff --git a/web/src/views/AdminView.vue b/web/src/views/AdminView.vue
index 4d24d99..7c3e5c1 100644
--- a/web/src/views/AdminView.vue
+++ b/web/src/views/AdminView.vue
@@ -1,9 +1,10 @@
 <script setup>
 import { ref, reactive, computed, onMounted, nextTick } from 'vue'
-import { api, getToken, setToken, clearToken } from '../api.js'
+import { api, apiPublic, getToken, setToken, clearToken } from '../api.js'
 import { escapeSmartHtml, decodeEntities, stripHtmlAndDecode } from '../htmlUtil.mjs'
 
 const authed = ref(false)
+const booting = ref(Boolean(getToken()))
 const loginUser = ref('')
 const loginPass = ref('')
 const loginMsg = ref('')
@@ -13,123 +14,218 @@ const view = ref('list')
 const currentSetId = ref(null)
 const qlist = ref([])
 const busy = ref(false)
+const notice = reactive({ text: '', type: 'ok' })
+let setsRequestId = 0
 
 const keyOf = i => String.fromCharCode(65 + i)
 
 const DEFAULT_LV_NAMES = ['基础语法', '控制流与函数', '集合', '面向对象', '空安全与异步', 'Flutter 入门']
 
-const setForm = reactive({ show: false, editingId: null, title: '', name: '', lvNames: [...DEFAULT_LV_NAMES], msg: '' })
+const setForm = reactive({ show: false, editingId: null, title: '', name: '', description: '', lvNames: [...DEFAULT_LV_NAMES], msg: '' })
 const importForm = reactive({ show: false, text: '', name: '', msg: '' })
 const importFileRef = ref(null)
 const qForm = reactive({
   show: false, editingId: null, title: '',
   lv: '1', q: '', exp: '', opts: [], ans: '', msg: ''
 })
+const qFormSnapshot = ref('')
 
 const currentSet = computed(() => sets.value.find(s => s.id === currentSetId.value) || null)
+const publishedCount = computed(() => sets.value.filter(s => s.published).length)
+const totalQuestions = computed(() => sets.value.reduce((sum, s) => sum + s.count, 0))
+const qFormDirty = computed(() => qForm.show && qFormSnapshot.value && serializeQuestionForm() !== qFormSnapshot.value)
 
 const lvNameOptions = computed(() => {
   const names = currentSet.value?.lvNames
   return (Array.isArray(names) && names.length === 6) ? names : DEFAULT_LV_NAMES
 })
 
-async function checkAuth() {
-  if (!getToken()) return
-  try {
-    await api('/admin/sets')
-    authed.value = true
-  } catch (e) {
-    clearToken()
+function showNotice(text, type = 'ok') {
+  notice.text = text
+  notice.type = type
+}
+
+function resetAdminUi() {
+  view.value = 'list'
+  currentSetId.value = null
+  sets.value = []
+  qlist.value = []
+  setForm.show = false
+  importForm.show = false
+  resetQuestionForm()
+  notice.text = ''
+}
+
+function handleError(e) {
+  if (e.status === 401) {
+    authed.value = false
+    resetAdminUi()
+    loginMsg.value = '登录已过期，请重新登录'
+  } else {
+    showNotice(e.message, 'err')
   }
 }
 
 async function doLogin() {
+  if (busy.value) return
   loginMsg.value = ''
   if (!loginUser.value.trim() || !loginPass.value) { loginMsg.value = '请输入用户名和密码'; return }
+  busy.value = true
   try {
-    const data = await api('/admin/login', {
+    const data = await apiPublic('/admin/login', {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ username: loginUser.value.trim(), password: loginPass.value })
     })
     setToken(data.token)
+    await loadSets()
     authed.value = true
+    loginPass.value = ''
   } catch (e) {
     loginMsg.value = e.message
+  } finally {
+    busy.value = false
   }
 }
 
 function doLogout() {
+  if (busy.value || !canDiscardQuestionForm()) return
   clearToken()
   authed.value = false
-  view.value = 'list'
+  resetAdminUi()
 }
 
 async function loadSets() {
-  const data = await api('/admin/sets')
+  const requestId = ++setsRequestId
+  let data
+  try {
+    data = await api('/admin/sets')
+  } catch (e) {
+    if (requestId !== setsRequestId) return false
+    throw e
+  }
+  if (requestId !== setsRequestId) return false
   sets.value = data.sets
+  return true
 }
 
-function esc(s) {
-  return String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;')
+async function refreshAfterMutation(message, includeDetail = false) {
+  showNotice(message)
+  try {
+    const requests = [loadSets()]
+    if (includeDetail && currentSetId.value != null) requests.push(renderQuestions())
+    await Promise.all(requests)
+  } catch (e) {
+    if (e.status === 401) handleError(e)
+    else showNotice(`${message}，但页面刷新失败：${e.message}`, 'err')
+  }
 }
 
-/* ---------- 套题：新增 / 重命名 / 删除 ---------- */
+/* ---------- 套题：新增 / 编辑 / 删除 ---------- */
 function showAddSet() {
+  if (busy.value) return
+  importForm.show = false
   setForm.show = true
   setForm.editingId = null
   setForm.title = '新增套题'
   setForm.name = ''
+  setForm.description = ''
   setForm.lvNames = [...DEFAULT_LV_NAMES]
   setForm.msg = ''
 }
 
 function showRenameSet(id) {
+  if (busy.value) return
   const s = sets.value.find(x => x.id === id)
   if (!s) return
   setForm.show = true
   setForm.editingId = id
-  setForm.title = '重命名套题'
+  setForm.title = '编辑套题信息'
   setForm.name = s.name
+  setForm.description = s.description || ''
   setForm.lvNames = s.lvNames ? [...s.lvNames] : [...DEFAULT_LV_NAMES]
   setForm.msg = ''
 }
 
 async function saveSet() {
+  if (busy.value) return
   setForm.msg = ''
   if (!setForm.name.trim()) { setForm.msg = '请输入套题名称'; return }
   const body = {
     name: setForm.name.trim(),
+    description: setForm.description.trim(),
     lvNames: setForm.lvNames.map(n => n.trim())
   }
   if (body.lvNames.some(n => !n)) { setForm.msg = '6 个难度名称都不能为空'; return }
+  busy.value = true
   try {
+    const editing = setForm.editingId !== null
     if (setForm.editingId === null) {
       await api('/admin/sets', { method: 'POST', body: JSON.stringify(body) })
     } else {
       await api('/admin/sets/' + setForm.editingId, { method: 'PUT', body: JSON.stringify(body) })
     }
     setForm.show = false
-    loadSets()
+    await refreshAfterMutation(editing ? '套题信息已更新' : '套题已创建为草稿，请添加题目后发布')
   } catch (e) {
-    setForm.msg = e.message
+    if (e.status === 401) handleError(e)
+    else setForm.msg = e.message
+  } finally {
+    busy.value = false
   }
 }
 
 async function deleteSet(id) {
+  if (busy.value) return
   const s = sets.value.find(x => x.id === id)
-  if (!confirm(`确定删除套题「${s.name}」吗？其下 ${s.questions.length} 道题将一并删除，不可恢复。`)) return
+  if (!s || !confirm(`确定删除套题「${s.name}」吗？其下 ${s.count} 道题将一并删除，不可恢复。`)) return
+  busy.value = true
   try {
     await api('/admin/sets/' + id, { method: 'DELETE' })
     if (currentSetId.value === id) backToList()
-    loadSets()
+    await refreshAfterMutation(`已删除套题「${s.name}」`)
   } catch (e) {
-    alert(e.message)
+    handleError(e)
+  } finally {
+    busy.value = false
+  }
+}
+
+async function togglePublish(set) {
+  if (busy.value || !set) return
+  const published = !set.published
+  if (!published && !confirm(`下架「${set.name}」后，答题端将暂时看不到它。确定继续吗？`)) return
+  busy.value = true
+  try {
+    await api('/admin/sets/' + set.id + '/publish', {
+      method: 'PATCH',
+      body: JSON.stringify({ published })
+    })
+    await refreshAfterMutation(published ? `「${set.name}」已发布` : `「${set.name}」已转为草稿`)
+  } catch (e) {
+    handleError(e)
+  } finally {
+    busy.value = false
+  }
+}
+
+async function duplicateSet(set) {
+  if (busy.value || !set) return
+  busy.value = true
+  try {
+    const data = await api('/admin/sets/' + set.id + '/duplicate', { method: 'POST' })
+    await refreshAfterMutation(`已复制为「${data.set.name}」，副本默认为草稿`)
+  } catch (e) {
+    handleError(e)
+  } finally {
+    busy.value = false
   }
 }
 
 /* ---------- 套题：导出 / 导入 ---------- */
 async function exportSet(id) {
+  if (busy.value) return
+  busy.value = true
   try {
     const data = await api('/admin/sets/' + id + '/export')
     const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' })
@@ -138,12 +234,17 @@ async function exportSet(id) {
     a.download = data.name + '.json'
     a.click()
     URL.revokeObjectURL(a.href)
+    showNotice('套题已导出')
   } catch (e) {
-    alert(e.message)
+    handleError(e)
+  } finally {
+    busy.value = false
   }
 }
 
 function showImport() {
+  if (busy.value) return
+  setForm.show = false
   importForm.show = true
   importForm.text = ''
   importForm.name = ''
@@ -170,6 +271,7 @@ function onImportFile(e) {
 }
 
 async function doImport() {
+  if (busy.value) return
   importForm.msg = ''
   const raw = importForm.text.trim()
   if (!raw) { importForm.msg = '请粘贴 JSON 或选择文件'; return }
@@ -180,46 +282,96 @@ async function doImport() {
     importForm.msg = 'JSON 解析失败：' + e.message
     return
   }
-  let name, questions
+  let name, description = '', lvNames, questions
   if (Array.isArray(parsed)) {
     questions = parsed
     name = importForm.name.trim()
   } else if (parsed && Array.isArray(parsed.questions)) {
     questions = parsed.questions
     name = importForm.name.trim() || parsed.name || ''
+    description = typeof parsed.description === 'string' ? parsed.description : ''
+    lvNames = parsed.lvNames
   } else {
     importForm.msg = '格式不支持：需要题目数组，或 {"name":..., "questions":[...]}'
     return
   }
   if (!name) { importForm.msg = '请填写套题名称'; return }
+  const body = { name, description, questions }
+  body.questions = questions.map(item => {
+    if (!item || typeof item !== 'object' || Array.isArray(item)) return item
+    return {
+      ...item,
+      q: typeof item.q === 'string' ? escapeSmartHtml(decodeEntities(item.q)) : item.q,
+      exp: typeof item.exp === 'string' ? escapeSmartHtml(decodeEntities(item.exp)) : item.exp
+    }
+  })
+  if (lvNames !== undefined && lvNames !== null) body.lvNames = lvNames
+  busy.value = true
   try {
-    const res = await api('/admin/import', { method: 'POST', body: JSON.stringify({ name, questions }) })
+    const res = await api('/admin/import', { method: 'POST', body: JSON.stringify(body) })
     importForm.show = false
-    loadSets()
-    alert('导入成功：共 ' + res.imported + ' 道题')
+    await refreshAfterMutation(`导入成功：共 ${res.imported} 道题${res.set.published ? '，已发布' : '，已保存为草稿'}`)
   } catch (e) {
-    importForm.msg = e.message
+    if (e.status === 401) handleError(e)
+    else importForm.msg = e.message
+  } finally {
+    busy.value = false
   }
 }
 
 /* ---------- 套题详情 ---------- */
 async function openSet(id) {
+  if (busy.value) return
+  resetQuestionForm()
   currentSetId.value = id
   view.value = 'detail'
-  await renderQuestions()
+  busy.value = true
+  try {
+    await renderQuestions()
+  } catch (e) {
+    handleError(e)
+    backToList(false)
+  } finally {
+    busy.value = false
+  }
 }
 
-function backToList() {
+function resetQuestionForm() {
+  qForm.show = false
+  qForm.editingId = null
+  qForm.msg = ''
+  qFormSnapshot.value = ''
+}
+
+function serializeQuestionForm() {
+  return JSON.stringify({ lv: qForm.lv, q: qForm.q, exp: qForm.exp, opts: qForm.opts.map(o => o.val), ans: qForm.ans })
+}
+
+function canDiscardQuestionForm() {
+  return !qFormDirty.value || confirm('当前题目有未保存的修改，确定放弃吗？')
+}
+
+function closeQuestionForm() {
+  if (canDiscardQuestionForm()) resetQuestionForm()
+}
+
+function backToList(refresh = true) {
+  if (!canDiscardQuestionForm()) return false
+  resetQuestionForm()
   view.value = 'list'
   currentSetId.value = null
-  loadSets()
+  qlist.value = []
+  if (refresh) loadSets().catch(handleError)
+  return true
 }
 
 async function renderQuestions() {
   if (currentSetId.value == null) return
-  const data = await api('/admin/sets')
-  const set = data.sets.find(s => s.id === currentSetId.value)
-  qlist.value = set ? set.questions : []
+  const data = await api('/admin/sets/' + currentSetId.value)
+  qlist.value = data.set.questions
+  const index = sets.value.findIndex(s => s.id === data.set.id)
+  const { questions, ...summary } = data.set
+  if (index !== -1) sets.value[index] = { ...sets.value[index], ...summary }
 }
 
 /* ---------- 题目 ---------- */
@@ -229,6 +381,7 @@ function resetOpts(opts) {
 }
 
 function showQuestionForm() {
+  if (!canDiscardQuestionForm()) return
   qForm.show = true
   qForm.editingId = null
   qForm.title = '新增题目'
@@ -238,6 +391,7 @@ function showQuestionForm() {
   qForm.msg = ''
   resetOpts(['', '', '', ''])
   syncAns()
+  qFormSnapshot.value = serializeQuestionForm()
   scrollFormIntoView()
 }
 
@@ -247,9 +401,14 @@ function addOpt() {
 }
 
 function removeOpt(i) {
+  if (qForm.opts.length <= 2) return
+  const answer = Number(qForm.ans)
   qForm.opts.splice(i, 1)
   qForm.opts.forEach((o, j) => { o.key = keyOf(j) })
-  syncAns()
+  if (Number.isInteger(answer)) {
+    if (answer === i) qForm.ans = ''
+    else if (answer > i) qForm.ans = String(answer - 1)
+  }
 }
 
 function syncAns() {
@@ -258,6 +417,7 @@ function syncAns() {
 }
 
 function editQuestion(id) {
+  if (!canDiscardQuestionForm()) return
   const item = qlist.value.find(x => x.id === id)
   if (!item) return
   qForm.show = true
@@ -269,6 +429,7 @@ function editQuestion(id) {
   qForm.msg = ''
   resetOpts(item.opts)
   qForm.ans = String(item.ans)
+  qFormSnapshot.value = serializeQuestionForm()
   scrollFormIntoView()
 }
 
@@ -298,6 +459,7 @@ function insertCode(target) {
 }
 
 async function saveQuestion() {
+  if (busy.value) return
   qForm.msg = ''
   const opts = qForm.opts.map(o => o.val.trim())
   const body = {
@@ -309,38 +471,62 @@ async function saveQuestion() {
   }
   if (!body.q) { qForm.msg = '请填写题干'; return }
   if (opts.length < 2 || opts.some(o => !o)) { qForm.msg = '请填写所有选项（至少 2 个且不能为空）'; return }
+  if (new Set(opts).size !== opts.length) { qForm.msg = '选项不能重复'; return }
+  if (!Number.isInteger(body.ans) || body.ans < 0 || body.ans >= opts.length) { qForm.msg = '请选择正确答案'; return }
+  if (!body.exp) { qForm.msg = '请填写答案解析'; return }
+  busy.value = true
   try {
+    const editing = qForm.editingId !== null
     if (qForm.editingId === null) {
       await api('/admin/sets/' + currentSetId.value + '/questions', { method: 'POST', body: JSON.stringify(body) })
     } else {
       await api('/admin/questions/' + qForm.editingId, { method: 'PUT', body: JSON.stringify(body) })
     }
     qForm.show = false
-    renderQuestions()
+    await refreshAfterMutation(editing ? '题目已更新' : '题目已添加', true)
   } catch (e) {
-    qForm.msg = e.message
+    if (e.status === 401) handleError(e)
+    else qForm.msg = e.message
+  } finally {
+    busy.value = false
   }
 }
 
 async function deleteQuestion(id) {
+  if (busy.value) return
   if (!confirm('确定删除题目 #' + id + ' 吗？此操作不可恢复。')) return
+  busy.value = true
   try {
     await api('/admin/questions/' + id, { method: 'DELETE' })
-    renderQuestions()
+    if (qForm.editingId === id) resetQuestionForm()
+    await refreshAfterMutation('题目已删除', true)
   } catch (e) {
-    alert(e.message)
+    handleError(e)
+  } finally {
+    busy.value = false
   }
 }
 
 onMounted(async () => {
-  await checkAuth()
-  if (authed.value) loadSets()
+  if (!getToken()) return
+  busy.value = true
+  try {
+    await loadSets()
+    authed.value = true
+  } catch (e) {
+    loginMsg.value = e.status === 401 ? '登录已过期，请重新登录' : `管理数据加载失败：${e.message}`
+  } finally {
+    busy.value = false
+    booting.value = false
+  }
 })
 </script>
 
 <template>
+  <div v-if="booting" class="empty-state" role="status" aria-live="polite">正在验证登录状态…</div>
+
   <!-- 登录 -->
-  <div v-if="!authed" class="card login-card">
+  <div v-else-if="!authed" class="card login-card">
     <div style="display:flex;align-items:center;gap:12px;margin-bottom:6px;">
       <div class="brand-seal small">印</div>
       <div>
@@ -349,58 +535,81 @@ onMounted(async () => {
       </div>
     </div>
     <div class="field" style="margin-top:20px;">
-      <label>用户名</label>
-      <input class="input" v-model="loginUser" placeholder="admin" @keydown.enter="doLogin">
+      <label for="admin-username">用户名</label>
+      <input id="admin-username" class="input" v-model="loginUser" autocomplete="username" placeholder="admin" @keydown.enter="doLogin">
     </div>
     <div class="field">
-      <label>密码</label>
-      <input class="input" type="password" v-model="loginPass" placeholder="请输入密码" @keydown.enter="doLogin">
+      <label for="admin-password">密码</label>
+      <input id="admin-password" class="input" type="password" v-model="loginPass" autocomplete="current-password" placeholder="请输入密码" @keydown.enter="doLogin">
     </div>
     <div class="msg err">{{ loginMsg }}</div>
-    <button class="btn btn-filled" style="width:100%;justify-content:center;margin-top:10px;" @click="doLogin">登 录</button>
+    <button class="btn btn-filled" style="width:100%;justify-content:center;margin-top:10px;" :disabled="busy" @click="doLogin">
+      {{ busy ? '登录中…' : '登 录' }}
+    </button>
   </div>
 
   <!-- 管理 -->
-  <div v-else>
+  <div v-else :inert="busy || undefined" :aria-busy="busy">
     <div class="toolbar">
       <div style="display:flex;align-items:center;gap:10px;">
         <template v-if="view === 'detail'">
-          <button class="btn btn-outline btn-sm" @click="backToList">← 返回</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="backToList">← 返回</button>
           <span style="font-family:var(--serif);font-weight:700;font-size:17px;">{{ currentSet?.name }}</span>
           <span style="font-size:12px;color:var(--ink-faint);">（{{ qlist.length }} 题）</span>
+          <span class="status-tag" :class="currentSet?.published ? 'published' : 'draft'">
+            {{ currentSet?.published ? '已发布' : '草稿' }}
+          </span>
         </template>
         <span v-else style="font-family:var(--serif);font-weight:900;font-size:19px;letter-spacing:2px;">套题集</span>
       </div>
       <div style="display:flex;gap:8px;">
         <template v-if="view === 'list'">
-          <button class="btn btn-tonal btn-sm" @click="showAddSet">＋ 新增套题</button>
-          <button class="btn btn-outline btn-sm" @click="showImport">⬆ 导入套题</button>
+          <button class="btn btn-tonal btn-sm" :disabled="busy" @click="showAddSet">＋ 新增套题</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="showImport">⬆ 导入套题</button>
         </template>
         <template v-else>
-          <button class="btn btn-tonal btn-sm" @click="showQuestionForm">＋ 新增题目</button>
+          <router-link v-if="currentSet?.published" class="btn btn-outline btn-sm preview-link" :to="{ path: '/quiz', query: { set: currentSetId } }">预览答题页</router-link>
+          <button v-else class="btn btn-outline btn-sm" disabled title="发布后可预览">预览答题页</button>
+          <button class="btn btn-tonal btn-sm" :disabled="busy" @click="showQuestionForm">＋ 新增题目</button>
         </template>
-        <button class="btn btn-outline btn-sm" @click="doLogout">退出</button>
+        <button class="btn btn-outline btn-sm" :disabled="busy" @click="doLogout">退出</button>
       </div>
     </div>
 
+    <div v-if="notice.text" class="notice" :class="notice.type" aria-live="polite">
+      <span>{{ notice.text }}</span>
+      <button type="button" aria-label="关闭提示" @click="notice.text = ''">×</button>
+    </div>
+
+    <div v-if="view === 'list'" class="admin-summary" aria-label="套题概况">
+      <div><b>{{ sets.length }}</b><span>套题总数</span></div>
+      <div><b>{{ publishedCount }}</b><span>已发布</span></div>
+      <div><b>{{ totalQuestions }}</b><span>题目总数</span></div>
+    </div>
+
     <!-- 套题表单（新增/重命名） -->
     <div v-if="setForm.show" class="card" style="padding:22px 24px;margin-bottom:20px;">
       <div style="font-weight:800;color:var(--primary);font-family:var(--serif);letter-spacing:1px;">{{ setForm.title }}</div>
       <div class="field" style="margin-top:12px;">
-        <label>套题名称</label>
-        <input class="input" v-model="setForm.name" placeholder="例如：Dart 语法测验" @keydown.enter="saveSet">
+        <label for="set-name">套题名称</label>
+        <input id="set-name" class="input" v-model="setForm.name" maxlength="80" placeholder="例如：Dart 语法测验" @keydown.enter="saveSet">
+      </div>
+      <div class="field">
+        <label for="set-description">套题简介（可选，答题端会展示）</label>
+        <textarea id="set-description" class="textarea" v-model="setForm.description" maxlength="240" placeholder="说明知识范围、适合人群或完成目标"></textarea>
+        <div class="char-count">{{ setForm.description.length }} / 240</div>
       </div>
       <div class="field">
         <label>6 个难度等级名称（答题页徽章与题目表单使用）</label>
         <div v-for="(n, i) in setForm.lvNames" :key="i" class="lv-row">
           <span class="lv-row-key">Lv{{ i + 1 }}</span>
-          <input class="input" v-model="setForm.lvNames[i]" :placeholder="'第 ' + (i + 1) + ' 级名称'">
+          <input class="input" v-model="setForm.lvNames[i]" :aria-label="`第 ${i + 1} 级名称`" :placeholder="'第 ' + (i + 1) + ' 级名称'">
         </div>
       </div>
       <div class="msg err">{{ setForm.msg }}</div>
       <div style="display:flex;gap:10px;margin-top:10px;">
-        <button class="btn btn-primary" @click="saveSet">保存</button>
-        <button class="btn btn-outline" @click="setForm.show = false">取消</button>
+        <button class="btn btn-primary" :disabled="busy" @click="saveSet">{{ busy ? '保存中…' : '保存' }}</button>
+        <button class="btn btn-outline" :disabled="busy" @click="setForm.show = false">取消</button>
       </div>
     </div>
 
@@ -410,7 +619,7 @@ onMounted(async () => {
       <div class="import-zone">
         <div>
           <input ref="importFileRef" type="file" accept=".json,application/json" style="display:none;" @change="onImportFile">
-          <button class="btn btn-outline btn-sm" @click="importFileRef?.click()">📁 选择 JSON 文件</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="importFileRef?.click()">📁 选择 JSON 文件</button>
           <span style="font-size:12px;color:var(--ink-faint);">（或直接粘贴下方 JSON）</span>
         </div>
         <div class="hint">
@@ -418,16 +627,16 @@ onMounted(async () => {
           ① {"name":"套题名", "questions":[{"lv":1,"q":"题干","opts":["A","B"],"ans":0,"exp":"解析"}]}<br>
           ② 仅题目数组 [{"lv":1,"q":"题干","opts":["A","B"],"ans":0,"exp":"解析"}]（名称在下方填写）
         </div>
-        <textarea class="textarea" style="margin-top:10px;min-height:110px;" v-model="importForm.text" placeholder="粘贴 JSON 内容，或选择文件后自动填入"></textarea>
+        <textarea class="textarea" style="margin-top:10px;min-height:110px;" v-model="importForm.text" aria-label="套题 JSON 内容" placeholder="粘贴 JSON 内容，或选择文件后自动填入"></textarea>
         <div class="field" style="margin-top:10px;">
-          <label>套题名称（格式②或覆盖默认名时填写）</label>
-          <input class="input" v-model="importForm.name" placeholder="留空则使用文件内的 name">
+          <label for="import-set-name">套题名称（格式②或覆盖默认名时填写）</label>
+          <input id="import-set-name" class="input" v-model="importForm.name" placeholder="留空则使用文件内的 name">
         </div>
       </div>
       <div class="msg err">{{ importForm.msg }}</div>
       <div style="display:flex;gap:10px;margin-top:10px;">
-        <button class="btn btn-primary" @click="doImport">开始导入</button>
-        <button class="btn btn-outline" @click="importForm.show = false">取消</button>
+        <button class="btn btn-primary" :disabled="busy" @click="doImport">{{ busy ? '导入中…' : '开始导入' }}</button>
+        <button class="btn btn-outline" :disabled="busy" @click="importForm.show = false">取消</button>
       </div>
     </div>
 
@@ -435,16 +644,23 @@ onMounted(async () => {
     <div v-if="view === 'list'" class="card">
       <div v-if="!sets.length" class="empty-state">暂无套题，点击「新增套题」创建第一套</div>
       <div v-for="s in sets" :key="s.id" class="set-item">
-        <div class="set-mark">{{ s.questions.length }}</div>
+        <div class="set-mark">{{ s.count }}</div>
         <div style="flex:1;min-width:0;">
-          <div class="set-name">{{ s.name }}</div>
-          <div class="set-sub">共 {{ s.questions.length }} 题</div>
+          <div class="set-title-row">
+            <div class="set-name">{{ s.name }}</div>
+            <span class="status-tag" :class="s.published ? 'published' : 'draft'">{{ s.published ? '已发布' : '草稿' }}</span>
+          </div>
+          <div class="set-sub">共 {{ s.count }} 题<span v-if="s.description"> · {{ s.description }}</span></div>
         </div>
         <div style="display:flex;gap:6px;flex-wrap:wrap;justify-content:flex-end;">
-          <button class="btn btn-tonal btn-sm" @click="openSet(s.id)">编辑题目</button>
-          <button class="btn btn-outline btn-sm" @click="showRenameSet(s.id)">重命名</button>
-          <button class="btn btn-outline btn-sm" @click="exportSet(s.id)">导出</button>
-          <button class="btn btn-danger btn-sm" @click="deleteSet(s.id)">删除</button>
+          <button class="btn btn-tonal btn-sm" :disabled="busy" @click="openSet(s.id)">编辑题目</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="showRenameSet(s.id)">编辑信息</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy || (!s.published && !s.count)" :title="!s.count ? '请先添加题目' : ''" @click="togglePublish(s)">
+            {{ s.published ? '下架' : '发布' }}
+          </button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="duplicateSet(s)">复制</button>
+          <button class="btn btn-outline btn-sm" :disabled="busy" @click="exportSet(s.id)">导出</button>
+          <button class="btn btn-danger btn-sm" :disabled="busy" @click="deleteSet(s.id)">删除</button>
         </div>
       </div>
     </div>
@@ -462,8 +678,8 @@ onMounted(async () => {
               <td><span class="seal" :class="'seal-lv' + (q.lv || 1)">Lv{{ q.lv || 1 }}</span></td>
               <td style="color:var(--ink-secondary);line-height:1.6;">{{ stripHtmlAndDecode(q.q).slice(0, 60) }}</td>
               <td style="white-space:nowrap;">
-                <button class="btn btn-outline btn-sm" @click="editQuestion(q.id)">编辑</button>
-                <button class="btn btn-danger btn-sm" @click="deleteQuestion(q.id)">删除</button>
+                <button class="btn btn-outline btn-sm" :disabled="busy" @click="editQuestion(q.id)">编辑</button>
+                <button class="btn btn-danger btn-sm" :disabled="busy" @click="deleteQuestion(q.id)">删除</button>
               </td>
             </tr>
           </tbody>
@@ -475,17 +691,17 @@ onMounted(async () => {
       <div v-if="qForm.show" class="qform" ref="qFormRef">
         <div style="font-weight:800;color:var(--primary);font-family:var(--serif);letter-spacing:1px;">{{ qForm.title }}</div>
         <div class="field">
-          <label>难度</label>
-          <select class="select" v-model="qForm.lv">
+          <label for="question-level">难度</label>
+          <select id="question-level" class="select" v-model="qForm.lv">
             <option v-for="(n, i) in lvNameOptions" :key="i" :value="String(i + 1)">{{ i + 1 }} - {{ n }}</option>
           </select>
         </div>
         <div class="field">
-          <label>题干（支持 HTML；代码里的 &lt; &gt; 会<b>自动转义</b>，不用手写 &amp;lt;）</label>
+          <label for="question-text">题干（支持 HTML；代码里的 &lt; &gt; 会<b>自动转义</b>，不用手写 &amp;lt;）</label>
           <div style="display:flex;gap:8px;margin-bottom:8px;">
             <button class="btn btn-outline btn-sm" @click="insertCode('q')">&lt;code&gt; 插入代码块</button>
           </div>
-          <textarea class="textarea" ref="qRef" v-model="qForm.q" placeholder="例如：Dart 程序的入口函数是？"></textarea>
+          <textarea id="question-text" class="textarea" ref="qRef" v-model="qForm.q" placeholder="例如：Dart 程序的入口函数是？"></textarea>
           <div v-if="qForm.q" class="preview">
             <div class="preview-head">实时预览</div>
             <div class="preview-body" v-html="qPreview"></div>
@@ -495,23 +711,24 @@ onMounted(async () => {
           <label>选项（至少 2 个，可增减）</label>
           <div v-for="(o, i) in qForm.opts" :key="i" class="opt-row">
             <span class="opt-row-key">{{ o.key }}</span>
-            <input class="input" v-model="o.val" :placeholder="'选项 ' + o.key">
-            <button class="btn btn-danger btn-sm" @click="removeOpt(i)">✕</button>
+            <input class="input" v-model="o.val" :aria-label="`选项 ${o.key}`" :placeholder="'选项 ' + o.key">
+            <button class="btn btn-danger btn-sm" :disabled="busy || qForm.opts.length <= 2" title="至少保留两个选项" @click="removeOpt(i)">✕</button>
           </div>
           <button class="btn btn-outline btn-sm" @click="addOpt">＋ 添加选项</button>
         </div>
         <div class="field">
-          <label>正确答案</label>
-          <select class="select" v-model="qForm.ans">
+          <label for="question-answer">正确答案</label>
+          <select id="question-answer" class="select" v-model="qForm.ans">
+            <option value="" disabled>请选择正确答案</option>
             <option v-for="(o, i) in qForm.opts" :key="i" :value="String(i)">{{ o.key }} - {{ stripHtmlAndDecode(o.val) || '（空）' }}</option>
           </select>
         </div>
         <div class="field">
-          <label>解析（答题后展示，支持 HTML；< & > 自动转义）</label>
+          <label for="question-explanation">解析（答题后展示，支持 HTML；&lt; &amp; &gt; 自动转义）</label>
           <div style="display:flex;gap:8px;margin-bottom:8px;">
             <button class="btn btn-outline btn-sm" @click="insertCode('exp')">&lt;code&gt; 插入代码块</button>
           </div>
-          <textarea class="textarea" ref="expRef" v-model="qForm.exp" placeholder="例如：入口是 &lt;b&gt;main()&lt;/b&gt;。"></textarea>
+          <textarea id="question-explanation" class="textarea" ref="expRef" v-model="qForm.exp" placeholder="例如：入口是 &lt;b&gt;main()&lt;/b&gt;。"></textarea>
           <div v-if="qForm.exp" class="preview">
             <div class="preview-head">实时预览</div>
             <div class="preview-body" v-html="expPreview"></div>
@@ -519,8 +736,8 @@ onMounted(async () => {
         </div>
         <div class="msg err">{{ qForm.msg }}</div>
         <div style="display:flex;gap:10px;margin-top:10px;">
-          <button class="btn btn-primary" @click="saveQuestion">保存</button>
-          <button class="btn btn-outline" @click="qForm.show = false">取消</button>
+          <button class="btn btn-primary" :disabled="busy" @click="saveQuestion">{{ busy ? '保存中…' : '保存' }}</button>
+          <button class="btn btn-outline" :disabled="busy" @click="closeQuestionForm">取消</button>
         </div>
       </div>
     </div>
@@ -541,6 +758,41 @@ onMounted(async () => {
   gap: 10px;
 }
 
+.notice {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  border-radius: 12px;
+  padding: 10px 14px;
+  margin-bottom: 14px;
+  font-size: 13px;
+  font-weight: 700;
+}
+.notice.ok { color: var(--on-success-container); background: var(--success-container); }
+.notice.err { color: var(--on-error-container); background: var(--error-container); }
+.notice button { border: 0; background: transparent; color: inherit; cursor: pointer; font-size: 18px; }
+
+.admin-summary {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 12px;
+  margin-bottom: 16px;
+}
+.admin-summary > div {
+  display: flex;
+  align-items: baseline;
+  gap: 8px;
+  padding: 13px 16px;
+  border: 1px solid var(--hairline);
+  border-radius: 14px;
+  background: var(--surface-alt);
+}
+.admin-summary b { color: var(--primary); font-family: var(--serif); font-size: 21px; }
+.admin-summary span { color: var(--ink-secondary); font-size: 12px; }
+.preview-link { text-decoration: none; }
+.char-count { text-align: right; color: var(--ink-faint); font-size: 11px; margin-top: 4px; }
+
 .set-item {
   display: flex;
   align-items: center;
@@ -561,7 +813,18 @@ onMounted(async () => {
   flex-shrink: 0;
 }
 .set-name { font-weight: 800; font-size: 15px; color: var(--ink); }
-.set-sub { font-size: 12px; color: var(--ink-faint); margin-top: 2px; }
+.set-title-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
+.set-sub { font-size: 12px; color: var(--ink-faint); margin-top: 3px; line-height: 1.5; }
+.status-tag {
+  display: inline-flex;
+  padding: 2px 8px;
+  border-radius: 999px;
+  font-size: 10.5px;
+  font-weight: 800;
+  white-space: nowrap;
+}
+.status-tag.published { background: var(--success-container); color: var(--on-success-container); }
+.status-tag.draft { background: var(--surface-high); color: var(--ink-secondary); }
 
 .import-zone {
   border: 1.5px dashed var(--hairline-strong);
@@ -617,4 +880,10 @@ onMounted(async () => {
 .preview-body :deep(code) { background: var(--surface-high); padding: 1px 6px; border-radius: 5px; font-family: 'Consolas', monospace; font-size: .92em; color: var(--primary); }
 .preview-body :deep(b) { color: var(--primary); }
 .preview-body :deep(pre) { background: var(--surface-high); border-radius: 10px; padding: 12px; overflow-x: auto; }
+
+@media (max-width: 640px) {
+  .admin-summary { grid-template-columns: 1fr; gap: 7px; }
+  .set-item { align-items: flex-start; flex-wrap: wrap; }
+  .set-item > div:last-child { width: 100%; justify-content: flex-start !important; }
+}
 </style>
diff --git a/web/src/views/QuizView.vue b/web/src/views/QuizView.vue
index ef2c60b..d341062 100644
--- a/web/src/views/QuizView.vue
+++ b/web/src/views/QuizView.vue
@@ -10,6 +10,7 @@ const loading = ref(true)
 const error = ref('')
 const sets = ref([])
 const questions = ref([])
+const sourceQuestions = ref([])
 const activeSetId = ref(null)
 const cur = ref(0)
 const score = ref(0)
@@ -17,7 +18,12 @@ const userAnswers = ref([])
 const answered = ref([])
 const offline = ref(false)
 const showResult = ref(false)
+const reviewingResult = ref(false)
+const resumed = ref(false)
+const activeVersion = ref('')
 const shuffle = ref(localStorage.getItem('quiz-shuffle') !== '0')
+let questionRequestId = 0
+let ignoredRouteId = null
 
 function shuffleList(arr) {
   const a = [...arr]
@@ -30,9 +36,10 @@ function shuffleList(arr) {
 
 /* ---------- 离线缓存 ---------- */
 // key 带版本号：以后改数据形状时，老缓存不会把页面带崩
-const CACHE_VER = 'v1'
+const CACHE_VER = 'v2'
 const setsCacheKey = () => `quiz-cache-${CACHE_VER}-sets`
 const setCacheKey = id => `quiz-cache-${CACHE_VER}-set-${id}`
+const progressKey = id => `quiz-progress-v1-set-${id}`
 
 function readCache(key) {
   try {
@@ -51,6 +58,14 @@ function writeCache(key, value) {
   }
 }
 
+function removeCache(key) {
+  try {
+    localStorage.removeItem(key)
+  } catch {
+    /* 无法访问本地存储时不影响答题 */
+  }
+}
+
 const DEFAULT_LV_NAMES = ['', '基础语法', '控制流与函数', '集合', '面向对象', '空安全与异步', 'Flutter 入门']
 const lvNames = ref(DEFAULT_LV_NAMES)
 
@@ -58,11 +73,14 @@ const keyOf = i => String.fromCharCode(65 + i)
 
 const total = computed(() => questions.value.length)
 const current = computed(() => questions.value[cur.value] || null)
+const activeSet = computed(() => sets.value.find(s => s.id === activeSetId.value) || null)
 const progress = computed(() => total.value ? ((cur.value + 1) / total.value * 100) : 0)
 const pct = computed(() => total.value ? Math.round(score.value / total.value * 100) : 0)
 const isLast = computed(() => cur.value === total.value - 1)
 const answeredHere = computed(() => answered.value[cur.value] || false)
 const isRight = computed(() => answeredHere.value && userAnswers.value[cur.value] === current.value.ans)
+const answeredCount = computed(() => answered.value.filter(Boolean).length)
+const hasProgress = computed(() => answeredCount.value > 0 || cur.value > 0 || showResult.value)
 
 function gradeOf(p) {
   if (p >= 90) return { title: '翰林之才', sub: 'Dart 已了然于心，可放心挥毫写 Flutter 了。' }
@@ -79,85 +97,178 @@ function optClass(i) {
   return {}
 }
 
-// 网络优先、缓存兜底：只要在线就一定拿到最新题目，
-// 管理后台改完题不会被旧缓存挡住，因此不需要额外的缓存失效机制。
-async function loadSets() {
-  loading.value = true
-  error.value = ''
-  let data = null
-  try {
-    data = await apiPublic('/sets')
-    writeCache(setsCacheKey(), data)
-    offline.value = false
-  } catch (e) {
-    data = readCache(setsCacheKey())
-    if (!data) {
-      error.value = '套题列表加载失败，本地也没有缓存，请联网后重试'
-      loading.value = false
-      return
-    }
-    offline.value = true
-  }
-  sets.value = data.sets
-  if (!sets.value.length) {
-    error.value = '暂无套题，请联系管理员添加'
-    loading.value = false
-    return
-  }
-  const want = Number(route.query.set)
-  const target = sets.value.find(s => s.id === want) || sets.value[0]
-  await loadQuestions(target.id)
+// 网络优先、缓存兜底；4xx 表示套题已下架或参数错误，不使用旧缓存“复活”它。
+function canUseCache(e) {
+  return !e.status || e.status >= 500
 }
 
-async function loadQuestions(setId) {
-  loading.value = true
-  error.value = ''
-  const key = setCacheKey(setId)
-  let data = null
-  try {
-    data = await apiPublic('/questions?set=' + setId)
-    writeCache(key, data)
-    offline.value = false
-  } catch (e) {
-    data = readCache(key)
-    if (!data) {
-      error.value = '该套题还没有缓存过，请联网后再打开一次'
-      loading.value = false
-      return
-    }
-    offline.value = true
-  }
+function persistProgress() {
+  if (!activeSetId.value || !questions.value.length) return
+  const answers = {}
+  questions.value.forEach((q, i) => {
+    if (answered.value[i]) answers[q.id] = userAnswers.value[i]
+  })
+  writeCache(progressKey(activeSetId.value), {
+    version: activeVersion.value,
+    questionIds: questions.value.map(q => q.id),
+    answers,
+    cur: cur.value,
+    showResult: showResult.value,
+    reviewingResult: reviewingResult.value,
+    completed: showResult.value || reviewingResult.value,
+    updatedAt: Date.now()
+  })
+}
 
-  // 本地判分依赖题目自带 ans。开发时 server 与 vite 是两个进程，
-  // 改完 server.js 忘了重启就会拿到不带 ans 的老数据，那样每题都会被判错。
-  if (data.questions.length && data.questions[0].ans === undefined) {
-    error.value = '服务端版本过旧（未下发答案），请重启 node server.js'
-    loading.value = false
-    return
-  }
-
-  questions.value = shuffle.value ? shuffleList(data.questions) : data.questions
-  activeSetId.value = setId
-  lvNames.value = Array.isArray(data.set.lvNames) && data.set.lvNames.length === 6
-    ? ['', ...data.set.lvNames]
-    : DEFAULT_LV_NAMES
+function startFresh(questionList) {
+  questions.value = shuffle.value ? shuffleList(questionList) : [...questionList]
   userAnswers.value = new Array(questions.value.length).fill(null)
   answered.value = new Array(questions.value.length).fill(false)
   cur.value = 0
   score.value = 0
   showResult.value = false
-  if (!questions.value.length) error.value = '该套题暂无题目，请联系管理员添加'
+  reviewingResult.value = false
+  resumed.value = false
+}
+
+function clearRoundState() {
+  questions.value = []
+  sourceQuestions.value = []
+  userAnswers.value = []
+  answered.value = []
+  cur.value = 0
+  score.value = 0
+  showResult.value = false
+  reviewingResult.value = false
+  resumed.value = false
+  activeVersion.value = ''
+}
+
+function restoreProgress(data) {
+  const saved = readCache(progressKey(data.set.id))
+  const byId = new Map(data.questions.map(q => [q.id, q]))
+  const ids = saved?.questionIds
+  const valid = saved?.version === data.set.version &&
+    Array.isArray(ids) && ids.length === data.questions.length && ids.every(id => byId.has(id))
+
+  if (!valid) {
+    removeCache(progressKey(data.set.id))
+    startFresh(data.questions)
+    return
+  }
+
+  questions.value = ids.map(id => byId.get(id))
+  userAnswers.value = questions.value.map(q => {
+    const answer = saved.answers?.[q.id]
+    return Number.isInteger(answer) && answer >= 0 && answer < q.opts.length ? answer : null
+  })
+  answered.value = userAnswers.value.map(answer => answer !== null)
+  score.value = questions.value.reduce((sum, q, i) => sum + (userAnswers.value[i] === q.ans ? 1 : 0), 0)
+  cur.value = Math.min(Math.max(Number(saved.cur) || 0, 0), questions.value.length - 1)
+  const completed = Boolean(saved.completed ?? saved.showResult)
+  reviewingResult.value = completed && Boolean(saved.reviewingResult)
+  showResult.value = completed && !reviewingResult.value
+  resumed.value = answered.value.some(Boolean) || cur.value > 0 || showResult.value
+}
+
+async function loadSets() {
+  const requestId = ++questionRequestId
+  loading.value = true
+  error.value = ''
+  let data = null
+  try {
+    data = await apiPublic('/sets')
+    if (requestId !== questionRequestId) return
+    writeCache(setsCacheKey(), data)
+    offline.value = false
+  } catch (e) {
+    if (requestId !== questionRequestId) return
+    data = canUseCache(e) ? readCache(setsCacheKey()) : null
+    if (!data) {
+      sets.value = []
+      activeSetId.value = null
+      clearRoundState()
+      error.value = e.message || '套题列表加载失败，请联网后重试'
+      loading.value = false
+      return
+    }
+    offline.value = true
+  }
+  sets.value = Array.isArray(data.sets) ? data.sets : []
+  if (!sets.value.length) {
+    activeSetId.value = null
+    clearRoundState()
+    error.value = '暂无已发布的套题，请稍后再来'
+    loading.value = false
+    return
+  }
+  const want = Number(route.query.set)
+  const target = sets.value.find(s => s.id === want) || sets.value[0]
+  if (want !== target.id) {
+    ignoredRouteId = target.id
+    await router.replace({ path: '/quiz', query: { set: target.id } })
+  }
+  await loadQuestions(target.id)
+}
+
+async function loadQuestions(setId) {
+  const requestId = ++questionRequestId
+  loading.value = true
+  error.value = ''
+  activeSetId.value = setId
+  const key = setCacheKey(setId)
+  let data = null
+  try {
+    data = await apiPublic('/questions?set=' + encodeURIComponent(setId))
+    if (requestId !== questionRequestId) return
+    writeCache(key, data)
+    offline.value = false
+  } catch (e) {
+    if (requestId !== questionRequestId) return
+    data = canUseCache(e) ? readCache(key) : null
+    if (!data) {
+      clearRoundState()
+      error.value = e.message || '该套题加载失败，请稍后重试'
+      loading.value = false
+      return
+    }
+    offline.value = true
+  }
+
+  if (!Array.isArray(data.questions) || !data.set) {
+    clearRoundState()
+    error.value = '套题数据格式不正确，请联系管理员'
+    loading.value = false
+    return
+  }
+  if (data.questions.length && data.questions.some(q => q.ans === undefined)) {
+    clearRoundState()
+    error.value = '服务端版本过旧（未下发答案），请重启 node server.js'
+    loading.value = false
+    return
+  }
+
+  activeSetId.value = data.set.id
+  activeVersion.value = data.set.version || ''
+  sourceQuestions.value = [...data.questions]
+  lvNames.value = Array.isArray(data.set.lvNames) && data.set.lvNames.length === 6
+    ? ['', ...data.set.lvNames]
+    : DEFAULT_LV_NAMES
+  restoreProgress(data)
+  if (!questions.value.length) error.value = '该套题暂无题目，请选择其他套题'
   loading.value = false
 }
 
 function pickSet(id) {
-  if (id === activeSetId.value) {
-    loadQuestions(id)
-    return
-  }
+  if (id === activeSetId.value) return
   router.replace({ path: '/quiz', query: { set: id } })
 }
 
+function retryCurrent() {
+  if (activeSetId.value && sets.value.some(s => s.id === activeSetId.value)) loadQuestions(activeSetId.value)
+  else loadSets()
+}
+
 // 本地同步判分：赋值与判分落在同一个渲染周期，不存在 ans 未知的中间态，
 // 因此没有"先红后绿"的闪烁，断网也照样能答。
 function choose(i) {
@@ -165,24 +276,48 @@ function choose(i) {
   userAnswers.value[cur.value] = i
   answered.value[cur.value] = true
   if (i === current.value.ans) score.value++
+  persistProgress()
 }
 
 function next() {
-  if (isLast.value) showResult.value = true
+  if (!answeredHere.value) return
+  if (isLast.value) {
+    showResult.value = true
+    reviewingResult.value = false
+  }
   else if (cur.value < total.value - 1) cur.value++
+  persistProgress()
 }
 
 function prev() {
   if (cur.value > 0) cur.value--
+  persistProgress()
 }
 
-function restart() {
-  if (shuffle.value) questions.value = shuffleList(questions.value)
+function restart(ask = false) {
+  if (ask && hasProgress.value && !confirm('确定清除当前进度并重新开始吗？')) return
+  questions.value = shuffle.value ? shuffleList(sourceQuestions.value) : [...sourceQuestions.value]
   userAnswers.value = new Array(questions.value.length).fill(null)
   answered.value = new Array(questions.value.length).fill(false)
   cur.value = 0
   score.value = 0
   showResult.value = false
+  reviewingResult.value = false
+  resumed.value = false
+  persistProgress()
+}
+
+function reviewQuestion(i) {
+  cur.value = i
+  showResult.value = false
+  reviewingResult.value = true
+  persistProgress()
+}
+
+function backToResult() {
+  showResult.value = true
+  reviewingResult.value = false
+  persistProgress()
 }
 
 function toggleShuffle() {
@@ -191,8 +326,17 @@ function toggleShuffle() {
 
 watch(() => route.query.set, v => {
   const id = Number(v)
+  if (id === ignoredRouteId) {
+    ignoredRouteId = null
+    return
+  }
   if (id && id !== activeSetId.value && sets.value.some(s => s.id === id)) {
     loadQuestions(id)
+  } else if (sets.value.length && (!id || !sets.value.some(s => s.id === id))) {
+    const fallback = sets.value[0].id
+    ignoredRouteId = fallback
+    router.replace({ path: '/quiz', query: { set: fallback } })
+    if (fallback !== activeSetId.value) loadQuestions(fallback)
   }
 })
 
@@ -201,38 +345,64 @@ onMounted(loadSets)
 
 <template>
   <div>
-    <div v-if="loading" class="empty-state">墨已研好，正在取题…</div>
-
-    <div v-else-if="error" class="card empty-state">{{ error }}</div>
+    <div v-if="loading && !sets.length" class="empty-state" role="status" aria-live="polite">墨已研好，正在取题…</div>
 
     <template v-else>
-      <div class="card" style="padding:18px 24px;">
-        <div style="display:flex;align-items:center;gap:8px;flex-wrap:wrap;">
-          <span style="font-size:12.5px;color:var(--ink-secondary);font-weight:700;letter-spacing:1px;">选一套题</span>
+      <div v-if="sets.length" class="card set-picker">
+        <div class="set-picker-row">
+          <span class="set-picker-label">选一套题</span>
           <button
             v-for="s in sets" :key="s.id"
             class="chip" :class="{ active: s.id === activeSetId }"
+            :disabled="loading && s.id === activeSetId"
             @click="pickSet(s.id)">
             {{ s.name }}<span class="chip-count">{{ s.count }}</span>
           </button>
+        </div>
+        <div v-if="activeSet" class="set-meta">
+          <div>
+            <b>{{ activeSet.name }}</b>
+            <span>{{ activeSet.description || `共 ${activeSet.count} 道题，覆盖 6 个难度阶段` }}</span>
+          </div>
+          <div class="set-tools">
+            <span v-if="hasProgress && !loading" class="saved-tag">已保存 {{ answeredCount }}/{{ total }} 题</span>
+            <button v-if="hasProgress && !loading" class="text-action" @click="restart(true)">重新开始</button>
+          </div>
+        </div>
+        <div class="set-options">
           <label class="shuffle-toggle" title="开启后，每次进入或重开套题都会打乱题目顺序">
             <input type="checkbox" v-model="shuffle" @change="toggleShuffle">
-            <span>打乱题目顺序</span>
+            <span>重新开始时打乱题序</span>
           </label>
           <span v-if="offline" class="offline-tag" title="当前使用本地缓存的题目，联网后会自动取最新">离线 · 使用本地缓存</span>
+          <span v-else-if="resumed" class="resumed-tag">已恢复上次进度</span>
+        </div>
+      </div>
+
+      <div v-if="loading" class="card loading-card" role="status" aria-live="polite">正在加载「{{ activeSet?.name || '套题' }}」…</div>
+
+      <div v-else-if="error" class="card error-card" role="alert">
+        <div class="error-mark">!</div>
+        <div>
+          <h2>暂时无法打开套题</h2>
+          <p>{{ error }}</p>
+          <button class="btn btn-filled btn-sm" @click="retryCurrent">重新加载</button>
         </div>
       </div>
 
       <transition name="slide" mode="out-in">
-        <div v-if="!showResult" :key="cur" class="card quiz-card">
+        <div v-if="!loading && !error && current && !showResult" :key="cur" class="card quiz-card">
           <div style="display:flex;align-items:baseline;justify-content:space-between;margin-bottom:6px;">
             <div class="q-num">第 {{ cur + 1 }} 题 · 共 {{ total }} 题</div>
-            <div class="score-pill">{{ score }} 分</div>
+            <div class="score-pill">答对 {{ score }} 题</div>
+          </div>
+          <div class="bar" role="progressbar" :aria-valuenow="cur + 1" aria-valuemin="1" :aria-valuemax="total" :aria-label="`答题进度：第 ${cur + 1} 题，共 ${total} 题`">
+            <div class="bar-fill" :style="{ width: progress + '%' }"></div>
           </div>
-          <div class="bar"><div class="bar-fill" :style="{ width: progress + '%' }"></div></div>
 
           <div class="q-head">
-            <span class="seal" :class="'seal-lv' + (current.lv || 1)">{{ lvNames[current.lv] || '基础' }}</span>          </div>
+            <span class="seal" :class="'seal-lv' + (current.lv || 1)">{{ lvNames[current.lv] || '基础' }}</span>
+          </div>
 
           <h2 class="q-title" v-html="current.q"></h2>
 
@@ -261,15 +431,18 @@ onMounted(loadSets)
 
           <div class="btns">
             <button class="btn btn-outline" :disabled="cur === 0" @click="prev">上一题</button>
-            <button class="btn btn-filled" @click="next">
+            <button v-if="reviewingResult" class="btn btn-tonal" @click="backToResult">返回成绩</button>
+            <button class="btn btn-filled" :disabled="!answeredHere" :title="answeredHere ? '' : '请先选择一个答案'" @click="next">
               {{ isLast ? '看成绩' : '下一题' }}
             </button>
           </div>
+          <div v-if="!answeredHere" class="answer-hint">选择答案后即可继续，进度会自动保存</div>
         </div>
       </transition>
 
       <transition name="pop">
-        <div v-if="showResult" class="card result-card">
+        <div v-if="!loading && !error && showResult" class="card result-card">
+          <div class="result-set-name">{{ activeSet?.name }}</div>
           <div class="circle" :style="{ '--p': pct }">
             <div class="circle-inner">
               <div class="score-num">{{ score }}</div>
@@ -280,19 +453,19 @@ onMounted(loadSets)
           <div class="grade-sub">{{ gradeOf(pct).sub }}</div>
 
           <div class="review">
-            <div class="review-head">答题回顾</div>
-            <div v-for="(q, i) in questions" :key="q.id" class="review-item">
+            <div class="review-head">答题回顾 · 点击题目查看解析</div>
+            <button v-for="(q, i) in questions" :key="q.id" class="review-item" @click="reviewQuestion(i)">
               <b style="color:var(--ink-faint);margin-right:6px;">{{ i + 1 }}.</b>
               <span class="review-text">{{ stripHtmlAndDecode(q.q).slice(0, 40) }}</span>
               <span v-if="userAnswers[i] === q.ans" class="review-verdict ok">✓ 对</span>
               <span v-else class="review-verdict no">
-                ✗ 错（你：{{ userAnswers[i] == null ? '未答' : keyOf(userAnswers[i]) }}，正：{{ keyOf(q.ans) }}）
+                  ✗ 错（你：{{ userAnswers[i] == null ? '未答' : keyOf(userAnswers[i]) }}，正：{{ keyOf(q.ans) }}）
               </span>
-            </div>
+            </button>
           </div>
 
           <div style="text-align:center;margin-top:20px;">
-            <button class="btn btn-filled" @click="restart">再答一场</button>
+            <button class="btn btn-filled" @click="restart(false)">再答一场</button>
           </div>
         </div>
       </transition>
@@ -301,6 +474,36 @@ onMounted(loadSets)
 </template>
 
 <style scoped>
+.set-picker { padding: 18px 24px; }
+.set-picker-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
+.set-picker-label { font-size: 12.5px; color: var(--ink-secondary); font-weight: 700; letter-spacing: 1px; }
+.set-meta {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  gap: 14px;
+  margin-top: 14px;
+  padding-top: 12px;
+  border-top: 1px solid var(--hairline);
+}
+.set-meta > div:first-child { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
+.set-meta b { color: var(--ink); font-size: 14px; }
+.set-meta span { color: var(--ink-faint); font-size: 12px; line-height: 1.5; }
+.set-tools { display: flex; align-items: center; gap: 9px; flex-shrink: 0; }
+.set-options { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-top: 10px; }
+.saved-tag { color: var(--success) !important; font-weight: 700; white-space: nowrap; }
+.text-action {
+  border: 0;
+  padding: 2px;
+  background: transparent;
+  color: var(--primary);
+  font: inherit;
+  font-size: 12px;
+  font-weight: 700;
+  cursor: pointer;
+}
+.text-action:hover { text-decoration: underline; }
+
 .chip {
   border: 1px solid var(--hairline);
   background: var(--surface-alt);
@@ -318,6 +521,7 @@ onMounted(loadSets)
 }
 .chip:hover { border-color: var(--ink); color: var(--ink); }
 .chip.active { background: var(--ink); border-color: var(--ink); color: var(--surface); }
+.chip:disabled { cursor: wait; opacity: .7; }
 .chip-count { font-size: 11px; opacity: .75; }
 
 .shuffle-toggle {
@@ -328,7 +532,6 @@ onMounted(loadSets)
   color: var(--ink-secondary);
   cursor: pointer;
   user-select: none;
-  margin-left: 6px;
 }
 .shuffle-toggle input { cursor: pointer; accent-color: var(--primary); }
 
@@ -346,6 +549,32 @@ onMounted(loadSets)
   white-space: nowrap;
 }
 
+.resumed-tag {
+  color: var(--on-success-container);
+  background: var(--success-container);
+  border-radius: 999px;
+  padding: 4px 11px;
+  font-size: 11.5px;
+  font-weight: 700;
+}
+
+.loading-card { text-align: center; color: var(--ink-secondary); padding: 34px; }
+.error-card { display: flex; align-items: flex-start; gap: 16px; }
+.error-card h2 { font-family: var(--serif); font-size: 18px; margin-bottom: 5px; }
+.error-card p { color: var(--ink-secondary); font-size: 13px; line-height: 1.7; margin-bottom: 14px; }
+.error-mark {
+  width: 34px;
+  height: 34px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  border-radius: 50%;
+  background: var(--error-container);
+  color: var(--error);
+  font-weight: 900;
+}
+
 .quiz-card { margin-top: 20px; }
 .q-num { font-family: var(--serif); font-weight: 700; font-size: 15px; color: var(--ink-secondary); letter-spacing: 1px; }
 .score-pill {
@@ -417,8 +646,10 @@ onMounted(loadSets)
 .explain-body { opacity: .9; }
 
 .btns { display: flex; justify-content: flex-end; gap: 12px; margin-top: 24px; }
+.answer-hint { text-align: right; color: var(--ink-faint); font-size: 11.5px; margin-top: 7px; }
 
 .result-card { margin-top: 20px; text-align: center; }
+.result-set-name { color: var(--ink-faint); font-size: 12px; font-weight: 700; letter-spacing: 1px; margin-bottom: 10px; }
 .circle {
   width: 150px; height: 150px;
   border-radius: 50%;
@@ -439,9 +670,30 @@ onMounted(loadSets)
 
 .review { text-align: left; border-top: 1px solid var(--hairline); padding-top: 14px; max-height: 300px; overflow-y: auto; }
 .review-head { font-weight: 800; color: var(--primary); font-size: 13px; margin-bottom: 8px; letter-spacing: 1px; }
-.review-item { font-size: 13px; padding: 9px 4px; border-bottom: 1px dashed var(--hairline); display: flex; align-items: center; gap: 6px; }
+.review-item {
+  width: 100%;
+  border: 0;
+  border-bottom: 1px dashed var(--hairline);
+  background: transparent;
+  color: inherit;
+  font-family: inherit;
+  text-align: left;
+  cursor: pointer;
+  font-size: 13px;
+  padding: 9px 4px;
+  display: flex;
+  align-items: center;
+  gap: 6px;
+}
+.review-item:hover { background: var(--surface-alt); }
 .review-text { color: var(--ink-secondary); flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .review-verdict { font-weight: 800; font-size: 12px; flex-shrink: 0; }
 .review-verdict.ok { color: var(--success); }
 .review-verdict.no { color: var(--error); }
+
+@media (max-width: 640px) {
+  .set-meta { align-items: flex-start; flex-direction: column; }
+  .set-tools { width: 100%; justify-content: space-between; }
+  .btns { flex-wrap: wrap; }
+}
 </style>