diff --git a/client/src/api/index.ts b/client/src/api/index.ts
index aad6b3f..85641c5 100644
--- a/client/src/api/index.ts
+++ b/client/src/api/index.ts
@@ -158,6 +158,7 @@ export const aiApi = {
   explain: (body: BodyOf<'/api/ai/explain-question', 'post'>) =>
     unwrap(apiClient.POST('/api/ai/explain-question', { body }))
 }
+export type AiExplain = SuccessBody<paths['/api/ai/explain-question']['post']>
 
 // ---- 个人档案 / 设置 ----
 export const profileApi = {
diff --git a/client/src/router/index.ts b/client/src/router/index.ts
index e7b2486..dc0953b 100644
--- a/client/src/router/index.ts
+++ b/client/src/router/index.ts
@@ -5,6 +5,7 @@ import PracticeView from '../views/practice/PracticeView.vue'
 import AnswerView from '../views/practice/AnswerView.vue'
 import CustomView from '../views/practice/CustomView.vue'
 import WrongDetailView from '../views/practice/WrongDetailView.vue'
+import AiExplainView from '../views/practice/AiExplainView.vue'
 import MockView from '../views/mock/MockView.vue'
 import MockFormView from '../views/mock/MockFormView.vue'
 import PlanView from '../views/plan/PlanView.vue'
@@ -22,6 +23,7 @@ export const routes: RouteRecordRaw[] = [
   { path: '/practice/custom', name: 'practice-custom', component: CustomView, meta: { title: '自定义组卷' } },
   { path: '/practice/wrong', name: 'practice-wrong', component: PracticeView, meta: { title: '错题本' } },
   { path: '/practice/wrong/:id', name: 'practice-wrong-detail', component: WrongDetailView, meta: { title: '错题详情' } },
+  { path: '/practice/explain', name: 'practice-explain', component: AiExplainView, meta: { title: 'AI 讲解' } },
   { path: '/practice/essay', name: 'practice-essay', component: PracticeView, meta: { title: '申论' } },
   { path: '/mock', name: 'mock', component: MockView, meta: { title: '模考分析' } },
   { path: '/mock/new', name: 'mock-new', component: MockFormView, meta: { title: '录入模考成绩' } },
diff --git a/client/src/views/practice/AiExplainView.vue b/client/src/views/practice/AiExplainView.vue
new file mode 100644
index 0000000..3a5cab1
--- /dev/null
+++ b/client/src/views/practice/AiExplainView.vue
@@ -0,0 +1,257 @@
+<script setup lang="ts">
+import { computed, onMounted, ref } from 'vue'
+import { useRoute, useRouter } from 'vue-router'
+import { aiApi, type AiExplain } from '../../api'
+import { useResponsive } from '../../composables/useResponsive'
+import AppCard from '../../components/base/AppCard.vue'
+import AppButton from '../../components/base/AppButton.vue'
+import AppIcon from '../../components/base/AppIcon.vue'
+import AppBadge from '../../components/base/AppBadge.vue'
+import AppLoading from '../../components/feedback/AppLoading.vue'
+import AppError from '../../components/feedback/AppError.vue'
+
+const route = useRoute()
+const router = useRouter()
+const { isMobile } = useResponsive()
+
+const questionId = computed(() => String(route.query.questionId ?? ''))
+const userAnswer = computed(() => String(route.query.userAnswer ?? '').toUpperCase())
+const requestType = computed<'standard' | 'deep'>(() =>
+  route.query.requestType === 'deep' ? 'deep' : 'standard'
+)
+
+const loading = ref(true)
+const error = ref('')
+const explain = ref<AiExplain | null>(null)
+
+onMounted(() => void load())
+
+async function load() {
+  if (!questionId.value) {
+    error.value = '缺少题目参数，无法生成讲解'
+    loading.value = false
+    return
+  }
+  loading.value = true
+  error.value = ''
+  try {
+    explain.value = await aiApi.explain({
+      questionId: questionId.value,
+      userAnswer: ['A', 'B', 'C', 'D'].includes(userAnswer.value)
+        ? (userAnswer.value as 'A' | 'B' | 'C' | 'D')
+        : undefined,
+      requestType: requestType.value
+    })
+  } catch (err) {
+    error.value = err instanceof Error ? err.message : 'AI 讲解加载失败'
+  } finally {
+    loading.value = false
+  }
+}
+
+function back() {
+  router.back()
+}
+
+const title = computed(() => (requestType.value === 'deep' ? 'AI 深度讲解' : 'AI 讲解'))
+const isAi = computed(() => explain.value?.source === 'ai')
+const mistakeText = computed(() => {
+  const list = explain.value?.commonMistakes ?? []
+  return list.length > 0 ? list : ['无明显高频错误']
+})
+</script>
+
+<template>
+  <div class="ai-explain">
+    <AppLoading v-if="loading" fullscreen text="正在生成讲解…" />
+    <AppError v-else-if="error" fullscreen title="讲解加载失败" :message="error" retry @retry="load" />
+
+    <template v-else-if="explain">
+      <!-- 顶栏 -->
+      <header class="ai-explain__top">
+        <button type="button" class="ai-explain__back" @click="back">
+          <AppIcon name="chevron-left" :size="20" />
+        </button>
+        <h1 class="ai-explain__title">{{ title }}</h1>
+        <AppBadge :variant="isAi ? 'primary' : 'soft'">
+          {{ isAi ? 'AI 生成' : '题库解析回退' }}
+        </AppBadge>
+      </header>
+
+      <!-- 结论 -->
+      <AppCard title="讲解结论" icon="sparkles">
+        <p class="ai-explain__summary">{{ explain.summary }}</p>
+        <p v-if="!isAi" class="ai-explain__fallback-tip">
+          AI 未配置或暂时不可用时自动回退到题库标准解析，不会阻塞你的刷题流程。
+        </p>
+      </AppCard>
+
+      <!-- 分步解析 -->
+      <AppCard title="分步解析" icon="book-open" v-if="explain.steps.length">
+        <ol class="ai-explain__steps">
+          <li v-for="(step, i) in explain.steps" :key="i" class="ai-explain__step">
+            <span class="ai-explain__step-index">{{ i + 1 }}</span>
+            <span class="ai-explain__step-text">{{ step }}</span>
+          </li>
+        </ol>
+      </AppCard>
+
+      <!-- 考点 -->
+      <AppCard title="考点" icon="target" v-if="explain.knowledgePoints.length">
+        <div class="ai-explain__tags">
+          <AppBadge v-for="(k, i) in explain.knowledgePoints" :key="i" variant="soft">{{ k }}</AppBadge>
+        </div>
+      </AppCard>
+
+      <!-- 常见错误 -->
+      <AppCard title="常见错误" icon="alert">
+        <ul class="ai-explain__mistakes">
+          <li v-for="(m, i) in mistakeText" :key="i">{{ m }}</li>
+        </ul>
+      </AppCard>
+
+      <!-- 答案 -->
+      <AppCard title="正确答案" icon="check">
+        <div class="ai-explain__answer">
+          <strong class="ai-explain__answer-key">{{ explain.answer }}</strong>
+          <span class="ai-explain__answer-label">本题答案为 {{ explain.answer }}</span>
+        </div>
+      </AppCard>
+
+      <AppButton v-if="!isMobile" variant="ghost" @click="back">
+        <AppIcon name="chevron-left" :size="16" />返回
+      </AppButton>
+    </template>
+  </div>
+</template>
+
+<style scoped>
+.ai-explain {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-5);
+}
+.ai-explain__top {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+}
+.ai-explain__back {
+  display: grid;
+  place-items: center;
+  width: 36px;
+  height: 36px;
+  flex: none;
+  border-radius: 50%;
+  background: var(--bg-card);
+  border: 1px solid var(--border-subtle);
+  color: var(--text-secondary);
+  cursor: pointer;
+}
+.ai-explain__title {
+  flex: 1;
+  margin: 0;
+  font-size: var(--fs-h2);
+  font-weight: var(--fw-h2);
+  color: var(--text-primary);
+}
+.ai-explain__summary {
+  margin: 0;
+  font-size: var(--fs-body);
+  line-height: var(--lh-body);
+  color: var(--text-primary);
+  white-space: pre-wrap;
+}
+.ai-explain__fallback-tip {
+  margin: var(--space-3) 0 0;
+  padding: var(--space-2) var(--space-3);
+  border-radius: var(--radius-sm);
+  background: var(--bg-soft);
+  font-size: var(--fs-label);
+  color: var(--text-secondary);
+}
+.ai-explain__steps {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-3);
+}
+.ai-explain__step {
+  display: flex;
+  gap: var(--space-3);
+  align-items: flex-start;
+}
+.ai-explain__step-index {
+  display: grid;
+  place-items: center;
+  width: 24px;
+  height: 24px;
+  flex: none;
+  border-radius: 50%;
+  background: var(--primary-soft, var(--bg-soft));
+  color: var(--primary);
+  font-size: var(--fs-label);
+  font-weight: var(--fw-label-bold);
+}
+.ai-explain__step-text {
+  font-size: var(--fs-subtitle);
+  line-height: var(--lh-subtitle);
+  color: var(--text-primary);
+  white-space: pre-wrap;
+}
+.ai-explain__tags {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--space-2);
+}
+.ai-explain__mistakes {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-2);
+}
+.ai-explain__mistakes li {
+  position: relative;
+  padding-left: var(--space-4);
+  font-size: var(--fs-subtitle);
+  line-height: var(--lh-subtitle);
+  color: var(--text-primary);
+}
+.ai-explain__mistakes li::before {
+  content: '';
+  position: absolute;
+  left: 0;
+  top: 8px;
+  width: 6px;
+  height: 6px;
+  border-radius: 50%;
+  background: var(--warning);
+}
+.ai-explain__answer {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+}
+.ai-explain__answer-key {
+  display: grid;
+  place-items: center;
+  width: 44px;
+  height: 44px;
+  flex: none;
+  border-radius: var(--radius-md);
+  background: var(--success);
+  color: var(--on-accent);
+  font-family: var(--font-num);
+  font-size: 20px;
+  font-weight: 700;
+}
+.ai-explain__answer-label {
+  font-size: var(--fs-subtitle);
+  font-weight: var(--fw-card-title);
+  color: var(--text-primary);
+}
+</style>
diff --git a/client/src/views/practice/AnswerView.vue b/client/src/views/practice/AnswerView.vue
index 5b67321..12f23f4 100644
--- a/client/src/views/practice/AnswerView.vue
+++ b/client/src/views/practice/AnswerView.vue
@@ -138,6 +138,13 @@ async function finishSession() {
   }
 }
 
+function goAiExplain(questionId: string, userAnswer: string) {
+  router.push({
+    name: 'practice-explain',
+    query: { questionId, userAnswer, requestType: 'standard' }
+  })
+}
+
 function backToPractice() {
   router.push('/practice')
 }
@@ -183,6 +190,14 @@ const finishAccuracy = computed(() => finishResult.value?.accuracy ?? 0)
                 <span>正确答案 <b class="is-right">{{ q.correctAnswer }}</b></span>
               </div>
               <p class="wrong-list__analysis">{{ q.analysis }}</p>
+              <AppButton
+                variant="ghost"
+                size="md"
+                class="wrong-list__ai"
+                @click="goAiExplain(q.questionId, q.userAnswer)"
+              >
+                <AppIcon name="sparkles" :size="14" />AI 讲解
+              </AppButton>
             </div>
           </div>
         </div>
@@ -264,7 +279,15 @@ const finishAccuracy = computed(() => finishResult.value?.accuracy ?? 0)
 
           <AppCard v-if="result.analysis" title="解析" icon="book-open">
             <p class="single-result__analysis">{{ result.analysis }}</p>
-            <AppButton block variant="secondary" icon="sparkles" class="single-result__ai">没看懂？让 AI 讲一讲</AppButton>
+            <AppButton
+              block
+              variant="secondary"
+              icon="sparkles"
+              class="single-result__ai"
+              @click="goAiExplain(question.id, selected)"
+            >
+              没看懂？让 AI 讲一讲
+            </AppButton>
           </AppCard>
 
           <div v-if="!result.correct" class="single-result__reason">
@@ -625,6 +648,9 @@ const finishAccuracy = computed(() => finishResult.value?.accuracy ?? 0)
   line-height: var(--lh-body);
   color: var(--text-secondary);
 }
+.wrong-list__ai {
+  margin-top: var(--space-2);
+}
 .result-note {
   margin: var(--space-4) 0 0;
   font-size: var(--fs-label);
diff --git a/client/src/views/practice/EssayView.vue b/client/src/views/practice/EssayView.vue
new file mode 100644
index 0000000..7ff97b4
--- /dev/null
+++ b/client/src/views/practice/EssayView.vue
@@ -0,0 +1,132 @@
+<script setup lang="ts">
+import AppCard from '../../components/base/AppCard.vue'
+import AppBadge from '../../components/base/AppBadge.vue'
+import AppIcon from '../../components/base/AppIcon.vue'
+
+const QUESTION_TYPES = [
+  { name: '归纳概括', desc: '概括给定资料的主要内容或问题' },
+  { name: '综合分析', desc: '对观点、现象进行多角度分析' },
+  { name: '提出对策', desc: '针对问题提出可行解决措施' },
+  { name: '贯彻执行', desc: '撰写公文、讲话稿等应用文' },
+  { name: '文章写作', desc: '围绕主题撰写议论文' }
+] as const
+</script>
+
+<template>
+  <div class="essay">
+    <!-- 功能说明 -->
+    <AppCard title="申论功能说明" icon="book-open">
+      <p class="essay__intro">
+        申论是公务员考试笔试科目之一，重点考查阅读理解、综合分析、解决问题与文字表达能力。
+        备考通当前聚焦行测闭环，申论功能正在规划中。
+      </p>
+      <div class="essay__types">
+        <div v-for="t in QUESTION_TYPES" :key="t.name" class="essay__type">
+          <AppBadge variant="primary">{{ t.name }}</AppBadge>
+          <span class="essay__type-desc">{{ t.desc }}</span>
+        </div>
+      </div>
+    </AppCard>
+
+    <!-- 后续入口 -->
+    <AppCard title="后续能力" icon="sparkles">
+      <ul class="essay__future">
+        <li>
+          <AppIcon name="pen" :size="16" />
+          <span>在线写作：按题型练习，支持计时作答</span>
+        </li>
+        <li>
+          <AppIcon name="sparkles" :size="16" />
+          <span>AI 批改：结合 AI 给出分项评分与改进建议</span>
+        </li>
+        <li>
+          <AppIcon name="chart" :size="16" />
+          <span>范文库：历年真题范文与素材积累</span>
+        </li>
+      </ul>
+    </AppCard>
+
+    <!-- 说明提示 -->
+    <AppCard :padded="true">
+      <div class="essay__notice">
+        <AppIcon name="alert" :size="18" />
+        <p>当前为占位页面，不保存任何写作内容。建议先完成行测「刷题 → 错题复习 → 模考分析」闭环。</p>
+      </div>
+    </AppCard>
+  </div>
+</template>
+
+<style scoped>
+.essay {
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-5);
+}
+.essay__intro {
+  margin: 0 0 var(--space-4);
+  font-size: var(--fs-body);
+  line-height: var(--lh-body);
+  color: var(--text-secondary);
+}
+.essay__types {
+  display: grid;
+  grid-template-columns: repeat(2, 1fr);
+  gap: var(--space-3);
+}
+.essay__type {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+  padding: var(--space-3);
+  border: 1px solid var(--border-subtle);
+  border-radius: var(--radius-md);
+  background: var(--bg-soft);
+}
+.essay__type-desc {
+  flex: 1;
+  min-width: 0;
+  font-size: var(--fs-label);
+  color: var(--text-secondary);
+}
+.essay__future {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: var(--space-3);
+}
+.essay__future li {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+  font-size: var(--fs-subtitle);
+  color: var(--text-primary);
+}
+.essay__future li svg {
+  color: var(--primary);
+  flex: none;
+}
+.essay__notice {
+  display: flex;
+  align-items: flex-start;
+  gap: var(--space-3);
+}
+.essay__notice svg {
+  color: var(--warning);
+  flex: none;
+  margin-top: 2px;
+}
+.essay__notice p {
+  margin: 0;
+  font-size: var(--fs-subtitle);
+  line-height: var(--lh-subtitle);
+  color: var(--text-secondary);
+}
+
+@media (max-width: 767px) {
+  .essay__types {
+    grid-template-columns: 1fr;
+  }
+}
+</style>
diff --git a/client/src/views/practice/PracticeView.vue b/client/src/views/practice/PracticeView.vue
index 604c03b..510f6ba 100644
--- a/client/src/views/practice/PracticeView.vue
+++ b/client/src/views/practice/PracticeView.vue
@@ -13,7 +13,7 @@ import AppIcon from '../../components/base/AppIcon.vue'
 import AppLoading from '../../components/feedback/AppLoading.vue'
 import AppError from '../../components/feedback/AppError.vue'
 import AppEmpty from '../../components/feedback/AppEmpty.vue'
-import ComingSoon from '../../components/feedback/ComingSoon.vue'
+import EssayView from './EssayView.vue'
 import { formatPercent, formatDateShort } from '../../utils/format'
 import type { IconName } from '../../components/base/icons'
 
@@ -387,7 +387,7 @@ const subtitle = computed(() => {
 
     <!-- ============ 申论 tab ============ -->
     <template v-else>
-      <ComingSoon />
+      <EssayView />
     </template>
   </div>
 </template>
diff --git a/client/src/views/practice/WrongDetailView.vue b/client/src/views/practice/WrongDetailView.vue
index ec2d1a6..ae877f5 100644
--- a/client/src/views/practice/WrongDetailView.vue
+++ b/client/src/views/practice/WrongDetailView.vue
@@ -96,6 +96,20 @@ function toggleReason(reason: string) {
 function backToList() {
   router.push('/practice/wrong')
 }
+
+/** AI 讲解：优先携带最近一次作答（历史最新一条），无历史则省略用户答案 */
+function goAiExplain() {
+  const questionId = detail.value?.questionId
+  if (!questionId) return
+  router.push({
+    name: 'practice-explain',
+    query: {
+      questionId,
+      userAnswer: detail.value?.history[0]?.userAnswer ?? '',
+      requestType: 'standard'
+    }
+  })
+}
 </script>
 
 <template>
@@ -149,7 +163,7 @@ function backToList() {
         <AppButton block size="lg" icon="refresh" @click="router.push(`/practice/session`)" disabled>
           重做此题
         </AppButton>
-        <AppButton block size="lg" variant="secondary" icon="sparkles" @click="router.push(`/questions`)" disabled>
+        <AppButton block size="lg" variant="secondary" icon="sparkles" @click="goAiExplain">
           AI 讲解
         </AppButton>
       </div>
diff --git a/docs/checks/task-11.md b/docs/checks/task-11.md
new file mode 100644
index 0000000..84bac5c
--- /dev/null
+++ b/docs/checks/task-11.md
@@ -0,0 +1,76 @@
+# 任务 11 检查记录：AI 讲解与申论占位
+
+日期：2026-09-01
+
+## 交付内容
+
+### 后端
+
+- `server/src/ai.ts`（新增）：
+  - `readAiConfig()`：从环境变量读取 `AI_BASE_URL` / `AI_API_KEY` / `AI_MODEL`（默认 gpt-4o-mini）/ `AI_TIMEOUT_MS`（默认 20000），未配置返回 null。
+  - `buildMessages()`：组装模块/题干/选项/标准答案/题库解析/标签/用户作答，要求模型输出严格 JSON（summary / steps / knowledgePoints / commonMistakes / answer）。
+  - `parseExplainJson()`：兼容 markdown 代码块等杂文的稳健 JSON 提取与字段校验。
+  - `explainWithAi()`：OpenAI 兼容 Chat Completions 调用（`${baseUrl}/chat/completions` + Bearer），AbortController 超时；未配置/超时/网络/HTTP/解析失败分别抛可识别错误；任何错误信息不含 API Key。
+- `server/src/handlers/ai.ts`（重写）：配置有效 → 调用 AI 并返回 `source:'ai'`；未配置 → `source:'fallback'`（「AI 尚未配置」）；超时 → `source:'fallback'`（「AI 请求超时」）；其余失败 → `source:'fallback'`（「AI 讲解暂时不可用」）。回退内容为题库解析 + 标签 + 答案，前端可识别。
+- `server/src/schemas/api.ts`：`AiExplainBodySchema.userAnswer` 改为可选（从错题详情进入且无作答历史时省略）。
+- `server/.env.example`（新增）：记录 PORT / DATA_DIR / AI 配置项说明。
+
+### 前端
+
+- `client/src/views/practice/AiExplainView.vue`（新增）：
+  - 路由 `/practice/explain?questionId=&userAnswer=&requestType=`，加载/错误/重试三态，缺少题目参数给出明确提示。
+  - 展示：来源徽章（AI 生成 / 题库解析回退）、讲解结论、分步解析（编号步骤）、考点（chip）、常见错误、正确答案（绿色高亮）；回退时显示说明提示条。
+  - `requestType=deep` 时标题为「AI 深度讲解」。
+- `client/src/views/practice/AnswerView.vue`：
+  - 单题结果「没看懂？让 AI 讲一讲」接入跳转（携带题目 ID + 用户答案）。
+  - 整卷结果页错题回顾每项新增「AI 讲解」入口。
+- `client/src/views/practice/WrongDetailView.vue`：AI 讲解按钮由占位禁用改为可用，携带题目 ID 与最近一次作答（无历史则省略）。
+- `client/src/views/practice/EssayView.vue`（新增）：申论占位页——功能说明（五大题型）、后续能力（在线写作/AI 批改/范文库）、不保存写作内容的提示。
+- `client/src/views/practice/PracticeView.vue`：申论 tab 由通用 ComingSoon 替换为 `EssayView`。
+- `client/src/router/index.ts`：新增 `/practice/explain`；`client/src/api/index.ts` 导出 `AiExplain` 类型。
+
+## 接口实测（本地 OpenAI 兼容 mock + curl）
+
+| 场景 | 结果 |
+|---|---|
+| 未配置 AI | `source:fallback`，「AI 尚未配置，已回退到题库标准解析（用户答案：A）」，steps=题库解析、answer=C |
+| 配置有效 Token（mock） | `source:ai`，summary/steps/knowledgePoints/commonMistakes/answer 结构化解析正确 |
+| deep 模式且无 userAnswer | 正常返回 `source:ai`（prompt 中用户作答为「未作答」） |
+| 超时（AI_TIMEOUT_MS=1200 + 8s 慢响应） | 1.2s 内返回 `source:fallback`，「AI 请求超时」 |
+| AI 返回不可解析内容 | `source:fallback`，「AI 讲解暂时不可用」 |
+| 非法输入 | 缺 questionId → VALIDATION_ERROR；不存在题目 → NOT_FOUND；非法 requestType → VALIDATION_ERROR |
+| Token 不泄漏 | 后端日志仅含请求方法/URL/状态码，无 API Key；OpenAPI 无 AI Token（仅有的 `apiKey` 字段是要闻 API 导入占位请求结构，任务06 既有）；前端源码无密钥 |
+
+## 浏览器检查（Chrome headless + CDP）
+
+| 场景 | 结果 |
+|---|---|
+| AI 讲解页（配置） | AI 生成徽章、结论、分步解析、考点、常见错误、答案 C 全部渲染 |
+| deep 模式 | 标题「AI 深度讲解」 |
+| 错题详情 AI 按钮 | 可用；点击跳转 `/practice/explain?questionId=demo-q-004&userAnswer=A` |
+| AI 未配置回退 UI | 「题库解析回退」徽章 + 回退说明 + 题库解析步骤 + 正确答案 |
+| 申论占位页 | 功能说明 + 五大题型 + 后续能力 + 不保存写作内容提示 |
+| 移动 390 | AI 讲解页与申论页均无横向溢出（390/390） |
+| 类型检查与构建 | vue-tsc / tsc 通过；生产构建 139 模块通过；`api:generate` 与 OpenAPI 一致 |
+
+截图：`deliverables/checks/task11-ai-desktop.png`、`task11-ai-mobile.png`、`task11-ai-fallback-desktop.png`、`task11-essay-desktop.png`、`task11-essay-mobile.png`。
+
+## 完成标准核对（开发计划任务11）
+
+- ✅ OpenAI 兼容客户端（Chat Completions + Bearer Token，环境变量配置）。
+- ✅ Token 配置读取（`AI_BASE_URL` / `AI_API_KEY` / `AI_MODEL` / `AI_TIMEOUT_MS`，`server/.env.example` 示例）。
+- ✅ 结构化讲解（summary / steps / knowledgePoints / commonMistakes / answer）。
+- ✅ 超时处理（AbortController + `AI_TIMEOUT_MS`，超时回退题库解析）。
+- ✅ 题库解析回退（未配置/超时/解析失败均回退，`source:fallback` 可识别，不阻塞刷题）。
+- ✅ 前端结果展示（AI 讲解页 + 刷题结果/错题详情入口 + 未配置与失败提示）。
+- ✅ 申论占位页面（功能说明与后续入口，不保存写作内容）。
+- ✅ Token 不出现在前端、OpenAPI 与日志。
+
+## 边界说明
+
+- 测试使用本地 OpenAI 兼容 mock 服务（127.0.0.1:3199/3198/3197）验证「配置有效」「超时」「不可解析」三条链路，未使用真实外部 Token。
+- 未配置 AI 时不影响刷题、错题复习、模考等任何流程；设置页 `aiConfigured` 同步反映配置状态。
+
+## 当前结论
+
+任务 11 完成：AI 讲解接口与前端结果页、未配置/超时/失败回退、申论占位页全部实测通过；桌面与移动双端可操作；Token 仅存于后端环境变量且未进入日志/文档/前端。
diff --git a/server/.env.example b/server/.env.example
new file mode 100644
index 0000000..a4f1520
--- /dev/null
+++ b/server/.env.example
@@ -0,0 +1,9 @@
+# 服务端口与数据目录（可选，默认 3000 与 server/data）
+PORT=3000
+# DATA_DIR=./data
+
+# AI 讲解（OpenAI 兼容 Chat Completions；不配置时讲解自动回退题库解析）
+# AI_BASE_URL=https://api.openai.com/v1
+# AI_API_KEY=sk-xxxxxxxx
+# AI_MODEL=gpt-4o-mini
+# AI_TIMEOUT_MS=20000
diff --git a/server/src/ai.ts b/server/src/ai.ts
new file mode 100644
index 0000000..979b7fe
--- /dev/null
+++ b/server/src/ai.ts
@@ -0,0 +1,159 @@
+import type { Question } from './schemas/entities.js'
+
+/**
+ * OpenAI 兼容 Chat Completions 客户端（Token 仅存在于服务端环境变量，不进入日志/文档/前端）。
+ * 配置：AI_BASE_URL / AI_API_KEY / AI_MODEL（可选，默认 gpt-4o-mini）/ AI_TIMEOUT_MS（可选，默认 20000）。
+ */
+
+export interface AiConfig {
+  baseUrl: string
+  apiKey: string
+  model: string
+  timeoutMs: number
+}
+
+export type RequestType = 'standard' | 'deep'
+
+export interface AiExplainResult {
+  source: 'ai'
+  summary: string
+  steps: string[]
+  knowledgePoints: string[]
+  commonMistakes: string[]
+  answer: string
+}
+
+/** 读取 AI 配置；未配置（缺 baseUrl 或 apiKey）返回 null，不抛错 */
+export function readAiConfig(): AiConfig | null {
+  const baseUrl = process.env.AI_BASE_URL?.trim()
+  const apiKey = process.env.AI_API_KEY?.trim()
+  if (!baseUrl || !apiKey) return null
+  const timeoutMs = Number(process.env.AI_TIMEOUT_MS ?? 20000)
+  return {
+    baseUrl: baseUrl.replace(/\/+$/, ''),
+    apiKey,
+    model: process.env.AI_MODEL?.trim() || 'gpt-4o-mini',
+    timeoutMs: Number.isFinite(timeoutMs) && timeoutMs > 0 ? timeoutMs : 20000
+  }
+}
+
+export class AiTimeoutError extends Error {
+  constructor() {
+    super('AI 请求超时')
+    this.name = 'AiTimeoutError'
+  }
+}
+
+const OPTION_TEXT: Record<string, string> = { A: 'A', B: 'B', C: 'C', D: 'D' }
+
+/** 组装题目上下文与用户作答，要求模型输出严格 JSON */
+function buildMessages(
+  question: Question,
+  userAnswer: string | undefined,
+  requestType: RequestType
+): Array<{ role: 'system' | 'user'; content: string }> {
+  const options = question.options
+    .map((o) => `${o.key}. ${o.text}`)
+    .join('\n')
+  const depth =
+    requestType === 'deep'
+      ? '请深入剖析命题思路、干扰项设计与易错点，步骤更细致。'
+      : '请用简洁清晰的语言讲清楚解题思路。'
+
+  const system =
+    '你是一位经验丰富的公务员考试行测讲师。请基于题目与用户作答输出 JSON，字段必须为：' +
+    '"summary"（一句话结论，字符串）、"steps"（解题步骤，字符串数组）、' +
+    '"knowledgePoints"（考点，字符串数组）、"commonMistakes"（常见错误，字符串数组）、' +
+    '"answer"（正确答案，只能是 A/B/C/D 之一）。不要输出 JSON 以外的内容。'
+
+  const user = [
+    `模块：${question.module}${question.subModule ? `（${question.subModule}）` : ''}`,
+    `难度：${question.difficulty ?? '未标注'}`,
+    `题干：${question.stem}`,
+    `选项：\n${options}`,
+    `标准答案：${question.answer}`,
+    `题库解析：${question.analysis ?? '（无）'}`,
+    `标签：${(question.tags ?? []).join('、') || '（无）'}`,
+    `用户作答：${userAnswer ? (OPTION_TEXT[userAnswer] ?? userAnswer) : '（未作答）'}`,
+    `讲解要求：${depth}`
+  ].join('\n')
+
+  return [
+    { role: 'system', content: system },
+    { role: 'user', content: user }
+  ]
+}
+
+/** 从模型回复中稳健提取 JSON（兼容 markdown 代码块与前后杂文） */
+export function parseExplainJson(content: string): AiExplainResult | null {
+  const start = content.indexOf('{')
+  const end = content.lastIndexOf('}')
+  if (start === -1 || end <= start) return null
+  let data: unknown
+  try {
+    data = JSON.parse(content.slice(start, end + 1))
+  } catch {
+    return null
+  }
+  if (typeof data !== 'object' || data === null) return null
+  const obj = data as Record<string, unknown>
+  const summary = typeof obj.summary === 'string' ? obj.summary.trim() : ''
+  const answer = typeof obj.answer === 'string' ? obj.answer.trim().toUpperCase() : ''
+  if (!summary || !['A', 'B', 'C', 'D'].includes(answer)) return null
+  const asStrings = (v: unknown): string[] =>
+    Array.isArray(v) ? v.filter((x): x is string => typeof x === 'string' && x.trim() !== '').map((x) => x.trim()) : []
+  return {
+    source: 'ai',
+    summary,
+    steps: asStrings(obj.steps),
+    knowledgePoints: asStrings(obj.knowledgePoints),
+    commonMistakes: asStrings(obj.commonMistakes),
+    answer
+  }
+}
+
+/**
+ * 调用 OpenAI 兼容接口完成一次讲解。
+ * - 未配置：抛错（由 handler 回退题库解析）；
+ * - 超时：抛 AiTimeoutError；
+ * - 网络/HTTP/解析失败：抛普通 Error。
+ * 任何错误信息都不包含 API Key。
+ */
+export async function explainWithAi(
+  question: Question,
+  userAnswer: string | undefined,
+  requestType: RequestType
+): Promise<AiExplainResult> {
+  const config = readAiConfig()
+  if (!config) throw new Error('AI 未配置')
+
+  const controller = new AbortController()
+  const timer = setTimeout(() => controller.abort(), config.timeoutMs)
+  try {
+    const res = await fetch(`${config.baseUrl}/chat/completions`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${config.apiKey}`
+      },
+      body: JSON.stringify({
+        model: config.model,
+        messages: buildMessages(question, userAnswer, requestType),
+        temperature: 0.4
+      }),
+      signal: controller.signal
+    })
+    if (!res.ok) throw new Error(`AI 服务响应异常（HTTP ${res.status}）`)
+    const data = (await res.json()) as { choices?: Array<{ message?: { content?: unknown } }> }
+    const content = data.choices?.[0]?.message?.content
+    if (typeof content !== 'string' || !content.trim()) throw new Error('AI 响应缺少内容')
+    const parsed = parseExplainJson(content)
+    if (!parsed) throw new Error('AI 响应解析失败')
+    return parsed
+  } catch (err) {
+    if (controller.signal.aborted) throw new AiTimeoutError()
+    throw err
+  } finally {
+    clearTimeout(timer)
+  }
+}
diff --git a/server/src/handlers/ai.ts b/server/src/handlers/ai.ts
index 33bffe4..98bdfaf 100644
--- a/server/src/handlers/ai.ts
+++ b/server/src/handlers/ai.ts
@@ -2,14 +2,28 @@ import type { FastifyRequest } from 'fastify'
 import { readData } from '../data/store.js'
 import { dataFiles } from '../data/files.js'
 import { ApiError } from '../errors.js'
+import { AiTimeoutError, explainWithAi, readAiConfig } from '../ai.js'
 import type { Question } from '../schemas/entities.js'
 import type { z } from 'zod'
 import { AiExplainBodySchema } from '../schemas/api.js'
 
+/** 题库解析回退结果（AI 未配置 / 超时 / 失败时返回，source=fallback 便于前端识别） */
+function fallbackExplain(question: Question, userAnswer: string | undefined, reason: string) {
+  return {
+    source: 'fallback' as const,
+    summary: `${reason}，已回退到题库标准解析（用户答案：${userAnswer ?? '未作答'}）`,
+    steps: [question.analysis],
+    knowledgePoints: question.tags ?? [],
+    commonMistakes: [],
+    answer: question.answer
+  }
+}
+
 /**
- * AI 讲解：返回结构化的讲解结果。
- * TODO 任务11：组装题目上下文调用 OpenAI 兼容接口，超时或未配置 Token 时回退到题库解析。
- * 当前固定返回题库解析回退结果，保证接口契约与前端可以先联调。
+ * AI 题目讲解：
+ * 1. 配置了 AI（AI_BASE_URL + AI_API_KEY）时调用 OpenAI 兼容接口，解析结构化讲解；
+ * 2. 未配置 / 超时 / 失败均回退题库解析，返回可识别提示（source=fallback），不阻塞刷题流程；
+ * 3. Token 只存在于环境变量，不进入日志、OpenAPI 与前端。
  */
 export async function explainQuestion(request: FastifyRequest) {
   const body = request.body as z.infer<typeof AiExplainBodySchema>
@@ -17,12 +31,14 @@ export async function explainQuestion(request: FastifyRequest) {
   const question = questions.find((q) => q.id === body.questionId)
   if (!question) throw ApiError.notFound('题目不存在')
 
-  return {
-    source: 'fallback' as const,
-    summary: `AI 讲解尚未接入，已回退到题库标准解析（用户答案：${body.userAnswer}）`,
-    steps: [question.analysis],
-    knowledgePoints: question.tags,
-    commonMistakes: [],
-    answer: question.answer
+  if (!readAiConfig()) {
+    return fallbackExplain(question, body.userAnswer, 'AI 尚未配置')
+  }
+
+  try {
+    return await explainWithAi(question, body.userAnswer, body.requestType)
+  } catch (err) {
+    const reason = err instanceof AiTimeoutError ? 'AI 请求超时' : 'AI 讲解暂时不可用'
+    return fallbackExplain(question, body.userAnswer, reason)
   }
 }
diff --git a/server/src/schemas/api.ts b/server/src/schemas/api.ts
index bb0cec5..1b04bd7 100644
--- a/server/src/schemas/api.ts
+++ b/server/src/schemas/api.ts
@@ -436,7 +436,8 @@ export const QuestionsRefsResponseSchema = z.object({
 // ---------- AI 讲解 ----------
 export const AiExplainBodySchema = z.object({
   questionId: z.string().min(1),
-  userAnswer: z.enum(OPTION_KEYS),
+  /** 用户答案；从错题详情进入且无作答历史时可省略 */
+  userAnswer: z.enum(OPTION_KEYS).optional(),
   requestType: z.enum(['standard', 'deep']).default('standard')
 })
 export const AiExplainResponseSchema = z.object({