feat: A1 短材料复现本单元理解词，并加入黑夜模式

课程内容 - 重写全部 21 个 A1 单元的听读材料，把本单元理解词织进听/读文本，单元内理解词复现率从约 20% 提升到约 77%（各单元 56–96%）。 - 修正 U01 房间号与机场大巴同为 thirty 的撞车（改为 17/30/40）。 - 校验器容差按级别读取（A1 为 8%），materials 覆盖率、字数、选项子串等校验全部通过；course_content_test 通过。黑夜模式 - app_theme 拆分明/暗两套调色板，AppColors 随亮度切换； main 用 theme/darkTheme/themeMode + builder 镜像已解析亮度；主题偏好持久化到快照；进度页新增“外观主题”切换。文档 - COURSE-PACK-JSON.md 更新 A1 词池覆盖（840/933）与材料复现约定。 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-09-18 11:16:09 +09:00
parent 9ab08c25ef
commit febfd30f49
93 changed files with 72676 additions and 274 deletions
@@ -77,7 +77,7 @@ class _AssessmentPreparationPageState extends State<AssessmentPreparationPage> {
              '这些数字帮助你判断准备程度，但不会替代本次评估。',
            ),
          ),
-          const SectionCard(
+          SectionCard(
            tint: AppColors.warm,
            child: Text(
              '评估规则\n'
@@ -90,7 +90,7 @@ class _OpenScene extends StatelessWidget {
            ),
            Text(
              recommended ? 'A0 · 推荐' : 'A0',
-              style: const TextStyle(color: AppColors.green),
+              style: TextStyle(color: AppColors.green),
            ),
          ],
        ),
@@ -111,7 +111,7 @@ class _LockedScene extends StatelessWidget {
  Widget build(BuildContext context) => SectionCard(
    child: Row(
      children: [
-        const Icon(Icons.lock_outline, color: AppColors.muted),
+        Icon(Icons.lock_outline, color: AppColors.muted),
        const SizedBox(width: 10),
        Expanded(
          child: Column(
@@ -686,7 +686,7 @@ class _DialoguePageState extends State<DialoguePage>
                tint: AppColors.warm,
                child: Text(
                  hint!,
-                  style: const TextStyle(color: AppColors.warmInk),
+                  style: TextStyle(color: AppColors.warmInk),
                ),
              ),
            if (aiNotice != null)
@@ -694,7 +694,7 @@ class _DialoguePageState extends State<DialoguePage>
                tint: AppColors.warm,
                child: Row(
                  children: [
-                    const Icon(
+                    Icon(
                      Icons.cloud_off_outlined,
                      size: 18,
                      color: AppColors.warmInk,
@@ -703,7 +703,7 @@ class _DialoguePageState extends State<DialoguePage>
                    Expanded(
                      child: Text(
                        aiNotice!,
-                        style: const TextStyle(
+                        style: TextStyle(
                          color: AppColors.warmInk,
                          fontSize: 13,
                        ),
@@ -715,7 +715,7 @@ class _DialoguePageState extends State<DialoguePage>
            if (validationError != null)
              Text(
                validationError!,
-                style: const TextStyle(color: AppColors.warmInk),
+                style: TextStyle(color: AppColors.warmInk),
              ),
            TextField(
              controller: controller,
@@ -757,7 +757,7 @@ class _DialoguePageState extends State<DialoguePage>
                transcriptEdited
                    ? '你修改了设备转写：这轮按文字作答保存。'
                    : '这是设备转写；未修改提交后会作为语音尝试保存。',
-                style: const TextStyle(color: AppColors.muted, fontSize: 12),
+                style: TextStyle(color: AppColors.muted, fontSize: 12),
              ),
            RecordingControls(
              recording: recording,
@@ -771,9 +771,9 @@ class _DialoguePageState extends State<DialoguePage>
              widget.state.keepRecordings
                  ? '录音只保存在本机，不会发送给 AI。'
                  : '录音仅供本次回听，离开后自动删除。',
-              style: const TextStyle(color: AppColors.muted, fontSize: 12),
+              style: TextStyle(color: AppColors.muted, fontSize: 12),
            ),
-            const Text(
+            Text(
              '文字输入可完成教学对话；即使使用语音输入，本受控教学对话也不会单独记为独立口语证据。',
              style: TextStyle(color: AppColors.muted, fontSize: 12),
            ),
@@ -792,7 +792,7 @@ class _DialoguePageState extends State<DialoguePage>
                tint: AppColors.warm,
                child: Text(
                  '下次可以注意：${latestFeedback!}',
-                  style: const TextStyle(color: AppColors.warmInk),
+                  style: TextStyle(color: AppColors.warmInk),
                ),
              ),
            PrimaryButton(
@@ -916,7 +916,7 @@ class _TurnAction extends StatelessWidget {
        const SizedBox(width: 4),
        Text(
          label,
-          style: const TextStyle(
+          style: TextStyle(
            fontSize: 12,
            color: AppColors.green,
            fontWeight: FontWeight.w500,
@@ -935,7 +935,7 @@ class _AssistChip extends StatelessWidget {
  Widget build(BuildContext context) => ActionChip(
    label: Text(label),
    backgroundColor: AppColors.surface,
-    side: const BorderSide(color: AppColors.line),
+    side: BorderSide(color: AppColors.line),
    onPressed: onTap,
  );
 }
@@ -62,7 +62,7 @@ class HomePage extends StatelessWidget {
          SectionCard(
            child: Row(
              children: [
-                const Icon(Icons.psychology_outlined, color: AppColors.green),
+                Icon(Icons.psychology_outlined, color: AppColors.green),
                const SizedBox(width: 10),
                Expanded(
                  child: Text(
@@ -92,7 +92,7 @@ class HomePage extends StatelessWidget {
                      isReview
                          ? '${(count * 2).clamp(2, 10)} 分钟'
                          : stageStep?.minutes ?? '12 分钟',
-                      style: const TextStyle(color: AppColors.green),
+                      style: TextStyle(color: AppColors.green),
                    ),
                  ],
                ),
@@ -195,7 +195,7 @@ class _FrameworkNote extends StatelessWidget {
      color: AppColors.warm,
      borderRadius: BorderRadius.circular(14),
    ),
-    child: const Row(
+    child: Row(
      children: [
        Icon(Icons.info_outline, color: AppColors.warmInk),
        SizedBox(width: 8),
@@ -5,6 +5,7 @@ import '../../core/ai_service.dart';
 import '../../core/app_theme.dart';
 import '../../core/models.dart';
 import '../../core/seed_courses.dart';
+import '../../core/speech_compare.dart';
 import '../../core/voice_service.dart';
 import '../../core/writing_feedback.dart';
 import '../../widgets/app_widgets.dart';
@@ -112,6 +113,7 @@ class _LessonFlowState extends State<LessonFlow> {
          correctAnswer: activity.answers.first,
          selectedAnswer: selectedAnswer,
          audioPlayed: listeningAudioPlayed,
+          missed: listeningMissed,
          onSelected: (value) => setState(() {
            selectedAnswer = value;
            if (listeningOptions[value] != activity.answers.first) {
@@ -119,11 +121,14 @@ class _LessonFlowState extends State<LessonFlow> {
            }
          }),
          onPlayed: () => setState(() => listeningAudioPlayed = true),
-          onLookup: () => showLexiconLookup(
-            context,
-            state: widget.state,
-            initialText: activity.listening,
-          ),
+          onLookup: () {
+            setState(() => listeningMissed = true);
+            showLexiconLookup(
+              context,
+              state: widget.state,
+              initialText: activity.listening,
+            );
+          },
          onContinue:
              selectedAnswer >= 0 &&
                  listeningOptions[selectedAnswer] == activity.answers.first
@@ -135,6 +140,7 @@ class _LessonFlowState extends State<LessonFlow> {
        content = _SpeakingStep(
          state: widget.state,
          text: activity.speaking,
+          tip: activity.speakingTip,
          keepRecording: widget.state.keepRecordings,
          onContinue: widget.state.completeSpeaking,
        );
@@ -190,7 +190,7 @@ class _IndependentStepState extends State<_IndependentStep>
            tint: AppColors.warm,
            child: Text(
              validationError!,
-              style: const TextStyle(color: AppColors.warmInk),
+              style: TextStyle(color: AppColors.warmInk),
            ),
          ),
        if (!widget.showHelp)
@@ -8,6 +8,7 @@ class _ListeningStep extends StatelessWidget {
    required this.correctAnswer,
    required this.selectedAnswer,
    required this.audioPlayed,
+    required this.missed,
    required this.onSelected,
    required this.onPlayed,
    required this.onLookup,
@@ -21,6 +22,9 @@ class _ListeningStep extends StatelessWidget {

  final int selectedAnswer;
  final bool audioPlayed;
+
+  /// 选错过或查看过原文；此后可以看原文，但本题不再算独立听辨。
+  final bool missed;
  final ValueChanged<int> onSelected;
  final VoidCallback onPlayed;
  final VoidCallback onLookup;
@@ -29,6 +33,9 @@ class _ListeningStep extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final answers = options;
+    final answeredCorrectly =
+        selectedAnswer >= 0 && answers[selectedAnswer] == correctAnswer;
+    final revealText = answeredCorrectly || missed;
    return _LessonScaffold(
      step: 2,
      child: SpacedColumn(
@@ -47,22 +54,23 @@ class _ListeningStep extends StatelessWidget {
              onPlayed: onPlayed,
            ),
          ),
-          TextButton.icon(
-            onPressed: onLookup,
-            icon: const Icon(Icons.menu_book_outlined),
-            label: const Text('查看词或短语'),
-          ),
-          if (audioPlayed)
-            SectionCard(child: LexiconText(activity.listening, state: state)),
+          if (!audioPlayed)
+            Text(
+              '先播放音频，听完再选择。原文会在作答后显示。',
+              style: TextStyle(color: AppColors.muted),
+            ),
+          if (revealText)
+            SectionCard(child: LexiconText(activity.listening, state: state))
+          else if (audioPlayed)
+            TextButton.icon(
+              onPressed: onLookup,
+              icon: const Icon(Icons.menu_book_outlined),
+              label: const Text('听不懂，查看原文和词义（本题不计入听辨）'),
+            ),
          for (var index = 0; index < answers.length; index++)
            SectionCard(
              tint: selectedAnswer == index ? AppColors.softGreen : null,
-              onTap: () {
-                onSelected(index);
-                if (!audioPlayed) {
-                  onPlayed();
-                }
-              },
+              onTap: audioPlayed ? () => onSelected(index) : null,
              child: Row(
                children: [
                  Icon(
@@ -74,18 +82,23 @@ class _ListeningStep extends StatelessWidget {
                        : AppColors.muted,
                  ),
                  const SizedBox(width: 10),
-                  Text(answers[index]),
+                  Text(
+                    answers[index],
+                    style: audioPlayed
+                        ? null
+                        : TextStyle(color: AppColors.muted),
+                  ),
                ],
              ),
            ),
          PrimaryButton(
            label: selectedAnswer >= 0
                ? '检查并继续'
-                : (audioPlayed ? '请选择答案' : '先播放音频或选择答案'),
+                : (audioPlayed ? '请选择答案' : '先播放音频'),
            onPressed: onContinue,
          ),
          if (selectedAnswer >= 0 && answers[selectedAnswer] != correctAnswer)
-            const Text(
+            Text(
              '再听一次，选择正确答案。',
              style: TextStyle(color: AppColors.warmInk),
            ),
@@ -95,7 +95,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
-                    const Row(
+                    Row(
                      children: [
                        Icon(
                          Icons.chat_bubble_outline,
@@ -117,7 +117,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                      onTap: () =>
                          VoiceService.instance.speak(widget.activity.reading),
                      borderRadius: BorderRadius.circular(16),
-                      child: const Padding(
+                      child: Padding(
                        padding: EdgeInsets.symmetric(
                          horizontal: 8,
                          vertical: 4,
@@ -194,7 +194,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                    color: AppColors.green.withValues(alpha: 0.12),
                    borderRadius: BorderRadius.circular(6),
                  ),
-                  child: const Text(
+                  child: Text(
                    '问题',
                    style: TextStyle(
                      color: AppColors.green,
@@ -207,7 +207,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                Expanded(
                  child: Text(
                    widget.activity.readingQuestion,
-                    style: const TextStyle(
+                    style: TextStyle(
                      fontSize: 15,
                      fontWeight: FontWeight.w600,
                      color: AppColors.ink,
@@ -279,7 +279,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                    color: AppColors.green.withValues(alpha: 0.3),
                  ),
                ),
-                child: const Row(
+                child: Row(
                  children: [
                    Icon(Icons.check_circle, color: AppColors.green, size: 20),
                    SizedBox(width: 8),
@@ -309,7 +309,7 @@ class _ReadingStepState extends State<_ReadingStep> {
                    color: AppColors.warmInk.withValues(alpha: 0.2),
                  ),
                ),
-                child: const Row(
+                child: Row(
                  children: [
                    Icon(
                      Icons.help_outline,
@@ -333,7 +333,7 @@ class _ReadingStepState extends State<_ReadingStep> {
            TextField(
              controller: controller,
              onChanged: (_) => setState(() {}),
-              decoration: const InputDecoration(
+              decoration: InputDecoration(
                hintText: '用英文输入答案',
                filled: true,
                fillColor: AppColors.surface,
@@ -346,7 +346,7 @@ class _ReadingStepState extends State<_ReadingStep> {
              tint: AppColors.warm,
              child: Text(
                '答案：${widget.activity.readingAnswer}',
-                style: const TextStyle(color: AppColors.warmInk),
+                style: TextStyle(color: AppColors.warmInk),
              ),
            ),
          if (!showAnswer &&
@@ -4,10 +4,12 @@ class _SpeakingStep extends StatefulWidget {
  const _SpeakingStep({
    required this.state,
    required this.text,
+    this.tip = '',
    required this.keepRecording,
    required this.onContinue,
  });
  final String text;
+  final String tip;
  final AppState state;
  final bool keepRecording;
  final VoidCallback onContinue;
@@ -78,21 +80,18 @@ class _SpeakingStepState extends State<_SpeakingStep>
          textAlign: TextAlign.center,
          style: const TextStyle(fontSize: 30, fontWeight: FontWeight.w600),
        ),
-        Text(
-          '/es - eɪtʃ - iː - en/',
-          style: Theme.of(context).textTheme.bodyMedium,
-        ),
        SectionCard(
          tint: AppColors.surfaceMuted,
          child: _AudioRow(label: '播放示范音', speech: widget.text),
        ),
-        const SectionCard(
-          tint: AppColors.warm,
-          child: Text(
-            '字母之间留一个短停顿。先清楚，不必快。',
-            style: TextStyle(color: AppColors.warmInk),
+        if (widget.tip.isNotEmpty)
+          SectionCard(
+            tint: AppColors.warm,
+            child: Text(
+              widget.tip,
+              style: TextStyle(color: AppColors.warmInk),
+            ),
          ),
-        ),
        SecondaryButton(
          label: transcribing
              ? '正在 AI 识别发音…'
@@ -137,9 +136,11 @@ class _SpeakingStepState extends State<_SpeakingStep>
            ),
          ),
        if (transcript.isNotEmpty)
-          SectionCard(child: Text("设备转写：$transcript\n请确认它是否接近你刚才说的内容。")),
+          _SpokenComparisonCard(expected: widget.text, transcript: transcript),
        const SectionCard(
-          child: Text('转写不确定或与原句不符时，可重说或继续文字练习；这一步只算跟读练习，不作为独立口语证据。'),
+          child: Text(
+            '转写只反映机器听成了什么，不等于发音评分；没听出的词可以再听示范、重说一次。这一步只算跟读练习，不作为独立口语证据。',
+          ),
        ),
        PrimaryButton(
          label: transcript.isEmpty ? '我已跟读，继续' : '确认并继续',
@@ -149,3 +150,54 @@ class _SpeakingStepState extends State<_SpeakingStep>
    ),
  );
 }
+
+class _SpokenComparisonCard extends StatelessWidget {
+  const _SpokenComparisonCard({
+    required this.expected,
+    required this.transcript,
+  });
+
+  final String expected;
+  final String transcript;
+
+  @override
+  Widget build(BuildContext context) {
+    final result = compareSpoken(expected, transcript);
+    final summary = result.matches
+        ? '每个词都被听出来了。'
+        : result.close
+        ? '大部分词都被听出来了，橙色的词再练一次。'
+        : '有几个词没被听出来：先听示范，再慢一点说。';
+    return SectionCard(
+      tint: result.close ? AppColors.softGreen : AppColors.warm,
+      child: SpacedColumn(
+        spacing: 8,
+        children: [
+          Text('听出 ${result.heardCount}/${result.total} 个词。$summary'),
+          Wrap(
+            spacing: 6,
+            runSpacing: 6,
+            children: [
+              for (final word in result.words)
+                Text(
+                  word.text,
+                  style: TextStyle(
+                    fontSize: 18,
+                    fontWeight: FontWeight.w600,
+                    color: word.heard ? AppColors.green : AppColors.warmInk,
+                    decoration: word.heard
+                        ? TextDecoration.none
+                        : TextDecoration.underline,
+                  ),
+                ),
+            ],
+          ),
+          Text(
+            '设备转写：$transcript',
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+        ],
+      ),
+    );
+  }
+}
@@ -152,7 +152,7 @@ class _WritingStepState extends State<_WritingStep> {
                  Text('还可补充：${aiFeedback!.missing.join('、')}'),
                if (aiFeedback!.suggestion != null)
                  Text('可参考改写：${aiFeedback!.suggestion}'),
-                const Text(
+                Text(
                  '这是学习帮助；请按自己的意思重写后再检查，系统不会仅凭 AI 建议记为掌握。',
                  style: TextStyle(fontSize: 12, color: AppColors.muted),
                ),
@@ -164,7 +164,7 @@ class _WritingStepState extends State<_WritingStep> {
            tint: AppColors.warm,
            child: Text(
              aiFeedbackError!,
-              style: const TextStyle(color: AppColors.warmInk),
+              style: TextStyle(color: AppColors.warmInk),
            ),
          ),
        if (result != null)
@@ -45,7 +45,7 @@ class _WelcomePageState extends State<WelcomePage> {
                ),
              ),
              const SizedBox(width: 12),
-              const Column(
+              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
@@ -312,7 +312,7 @@ class _PlacementPageState extends State<PlacementPage>
        label: '播放示范音',
        onPressed: () => VoiceService.instance.speak(_readAloudText),
      ),
-      const SectionCard(
+      SectionCard(
        tint: AppColors.surfaceMuted,
        child: Text('这一题只是开口热身，不录音、不打分，可以跳过。'),
      ),
@@ -130,14 +130,14 @@ class ProgressPage extends StatelessWidget {
                        ],
                      ),
                    ),
-                    const Icon(Icons.chevron_right, color: AppColors.muted),
+                    Icon(Icons.chevron_right, color: AppColors.muted),
                  ],
                ),
              );
            },
          ),
          if (state.a0Passed)
-            const SectionCard(
+            SectionCard(
              tint: AppColors.softGreen,
              child: Text('A0 已通过。A1 主线内容尚未提供，可继续进行 A0 巩固。'),
            ),
@@ -311,6 +311,41 @@ class _SettingsPageState extends State<SettingsPage> {
          activeThumbColor: AppColors.green,
          onChanged: widget.state.toggleKeepRecordings,
        ),
+        Padding(
+          padding: const EdgeInsets.fromLTRB(4, 10, 4, 6),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              const Text(
+                '外观主题',
+                style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
+              ),
+              const SizedBox(height: 4),
+              Text(
+                '深色模式适合夜间使用；跟随系统会随手机的深色开关自动切换',
+                style: TextStyle(fontSize: 12, color: AppColors.muted),
+              ),
+              const SizedBox(height: 10),
+              SizedBox(
+                width: double.infinity,
+                child: SegmentedButton<AppThemeMode>(
+                  segments: const [
+                    ButtonSegment(
+                      value: AppThemeMode.system,
+                      label: Text('跟随系统'),
+                    ),
+                    ButtonSegment(value: AppThemeMode.light, label: Text('浅色')),
+                    ButtonSegment(value: AppThemeMode.dark, label: Text('深色')),
+                  ],
+                  selected: {widget.state.themeMode},
+                  showSelectedIcon: false,
+                  onSelectionChanged: (selection) =>
+                      widget.state.setThemeMode(selection.first),
+                ),
+              ),
+            ],
+          ),
+        ),
        _SettingTile(
          title: '已保存的录音',
          subtitle: '回听或删除本机英语练习录音',
@@ -326,7 +361,7 @@ class _SettingsPageState extends State<SettingsPage> {
          '离线语音识别引擎',
          style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
        ),
-        const Text(
+        Text(
          '已内置 SenseVoice-Small 高精度离线语音识别模型 (INT8)。随 App 安装包直接打包，离线即用，无需额外下载，零网络流量消耗。',
          style: TextStyle(fontSize: 12, color: AppColors.muted),
        ),
@@ -335,14 +370,14 @@ class _SettingsPageState extends State<SettingsPage> {
          subtitle: SherpaSttService.instance.isReady
              ? '已就绪 · 本地离线识别 (16kHz WAV · INT8)'
              : '预加载就绪 · 已内置打包',
-          trailing: const Icon(Icons.check_circle, color: AppColors.green, size: 20),
+          trailing: Icon(Icons.check_circle, color: AppColors.green, size: 20),
        ),
        const Divider(height: 28),
        const Text(
          '云同步与多端备份',
          style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
        ),
-        const Text(
+        Text(
          '支持通过自建服务器在 Android / iOS / macOS 之间同步学习进度与复习掌握度。离线自动缓存，联网自动双向合并。',
          style: TextStyle(fontSize: 12, color: AppColors.muted),
        ),
@@ -363,7 +398,7 @@ class _SettingsPageState extends State<SettingsPage> {
          'AI 对话服务',
          style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
        ),
-        const Text(
+        Text(
          '订阅版 ChatGPT / Gemini 不能直接作为 App API 使用。请使用自己的 API Key，或填写兼容 OpenAI 接口的 CLIProxyAPI 地址。密钥不在此页面保存。',
          style: TextStyle(fontSize: 12, color: AppColors.muted),
        ),
@@ -568,7 +603,7 @@ class _SettingsPageState extends State<SettingsPage> {
                  SectionCard(
                    child: Row(
                      children: [
-                        const Icon(Icons.mic_none, color: AppColors.green),
+                        Icon(Icons.mic_none, color: AppColors.green),
                        const SizedBox(width: 10),
                        Expanded(
                          child: Text(
@@ -201,7 +201,7 @@ class _SyncSettingsSheetState extends State<SyncSettingsSheet> {
                    ),
                ],
              ),
-              const Text(
+              Text(
                '本地优先架构：无网络时不影响学习，联网后自动双向合并学习进度与复习掌握度。',
                style: TextStyle(fontSize: 13, color: AppColors.muted),
              ),
@@ -214,7 +214,7 @@ class _SyncSettingsSheetState extends State<SyncSettingsSheet> {
                                        children: [
                      Row(
                        children: [
-                          const CircleAvatar(
+                          CircleAvatar(
                            radius: 18,
                            backgroundColor: AppColors.softGreen,
                            child: Icon(Icons.person, color: AppColors.green),
@@ -232,7 +232,7 @@ class _SyncSettingsSheetState extends State<SyncSettingsSheet> {
                                ),
                                Text(
                                  _coordinator.serverUrl,
-                                  style: const TextStyle(
+                                  style: TextStyle(
                                    fontSize: 12,
                                    color: AppColors.muted,
                                  ),
@@ -27,7 +27,8 @@ class ReviewPage extends StatefulWidget {
  State<ReviewPage> createState() => _ReviewPageState();
 }

-class _ReviewPageState extends State<ReviewPage> {
+class _ReviewPageState extends State<ReviewPage>
+    with VoiceAnswerMixin<ReviewPage> {
  final controller = TextEditingController();
  bool showHint = false;
  bool usedHelp = false;
@@ -35,29 +36,78 @@ class _ReviewPageState extends State<ReviewPage> {
  bool generatingVariant = false;
  bool generatingLesson = false;

+  /// The untouched transcript of a spoken answer; null for typed answers.
+  String? transcript;
+  bool dictationPlayed = false;
+
+  @override
+  AppState get voiceState => widget.state;
+
  @override
  void dispose() {
+    VoiceService.instance.stopSpeaking();
+    disposeVoiceAnswer(keepRecording: widget.state.keepRecordings);
    controller.dispose();
    super.dispose();
  }

+  void _resetAnswer() {
+    controller.clear();
+    // A recording still held here was never attached to evidence.
+    VoiceService.instance.deleteRecording(recordingPath);
+    showHint = false;
+    usedHelp = false;
+    validationMessage = null;
+    transcript = null;
+    recordingPath = null;
+    dictationPlayed = false;
+  }
+
  void _next(ReviewItem item, {required bool assisted}) {
    final result = ReviewFeedback.check(item, controller.text);
    if (!result.complete) {
      setState(() => validationMessage = result.message);
      return;
    }
+    final answer = controller.text.trim();
+    final spoken = transcript != null;
    widget.state.completeReview(
      item,
      assisted: assisted,
-      rawAnswer: controller.text.trim(),
+      rawAnswer: answer,
+      inputMode: spoken && transcript == answer ? 'speechToText' : 'text',
+      originalTranscript: transcript,
+      recordingPath: spoken && widget.state.keepRecordings
+          ? recordingPath
+          : null,
    );
-    controller.clear();
-    setState(() {
-      showHint = false;
-      usedHelp = false;
-      validationMessage = null;
-    });
+    // A kept recording now belongs to the evidence row; don't delete it.
+    if (spoken && widget.state.keepRecordings) recordingPath = null;
+    setState(_resetAnswer);
+  }
+
+  Future<void> _toggleVoice() async {
+    if (aiVoiceRecording) {
+      await finishVoiceInput(
+        keepAudio: widget.state.keepRecordings,
+        onTranscript: (text) {
+          controller.text = text;
+          transcript = text;
+          validationMessage = null;
+        },
+      );
+      return;
+    }
+    await VoiceService.instance.stopSpeaking();
+    await startVoiceInput(unavailableMessage: '无法访问麦克风，请检查录音权限。你仍可输入英文作答。');
+  }
+
+  Future<void> _play(String text, {bool slow = false}) async {
+    try {
+      await VoiceService.instance.speak(text, slow: slow);
+    } finally {
+      if (mounted) setState(() => dictationPlayed = true);
+    }
  }

  Future<void> _generateVariant(ReviewItem item) async {
@@ -144,6 +194,11 @@ class _ReviewPageState extends State<ReviewPage> {
        ),
      );
    }
+    final dictation = item.skill == dictationSkill
+        ? a0DictationSentences[item.id]
+        : null;
+    final spokenTask = item.skill == spokenRecallSkill;
+    final audioText = reviewAudioText(item.id, item.target);
    final checkpoint =
        widget.state.mastery[item.id]?.checkpoint ?? item.successfulReviews;
    final checkpointLabel = checkpoint >= 4
@@ -153,19 +208,22 @@ class _ReviewPageState extends State<ReviewPage> {
      child: SpacedColumn(
        children: [
          Eyebrow('今天复习 · ${widget.state.dueReviewCount} 项待完成'),
-          Text('不看答案，试着回答。', style: Theme.of(context).textTheme.headlineMedium),
+          Text(
+            dictation != null ? '听一听，写下来。' : '不看答案，试着回答。',
+            style: Theme.of(context).textTheme.headlineMedium,
+          ),
          Text(
            '目标技能：${item.skill}',
            style: Theme.of(context).textTheme.bodyMedium,
          ),
          Text(
            checkpointLabel,
-            style: const TextStyle(color: AppColors.green, fontSize: 13),
+            style: TextStyle(color: AppColors.green, fontSize: 13),
          ),
          if (item.isAiGenerated)
            Row(
              children: [
-                const Expanded(
+                Expanded(
                  child: Text(
                    'AI 生成题面 · 已通过客户端结构审核',
                    style: TextStyle(color: AppColors.muted, fontSize: 12),
@@ -174,12 +232,7 @@ class _ReviewPageState extends State<ReviewPage> {
                TextButton(
                  onPressed: () {
                    widget.state.reportGeneratedReviewVariant(item);
-                    controller.clear();
-                    setState(() {
-                      showHint = false;
-                      usedHelp = false;
-                      validationMessage = null;
-                    });
+                    setState(_resetAnswer);
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(content: Text('已隔离该 AI 题面，并换回本地审核题。')),
                    );
@@ -192,7 +245,7 @@ class _ReviewPageState extends State<ReviewPage> {
            tint: AppColors.softGreen,
            child: SpacedColumn(
              children: [
-                const Text(
+                Text(
                  '情境',
                  style: TextStyle(
                    color: AppColors.green,
@@ -200,6 +253,22 @@ class _ReviewPageState extends State<ReviewPage> {
                  ),
                ),
                Text(item.prompt, style: const TextStyle(fontSize: 19)),
+                if (dictation != null)
+                  Row(
+                    children: [
+                      IconButton.filled(
+                        tooltip: '播放',
+                        onPressed: () => _play(dictation.sentence),
+                        icon: const Icon(Icons.play_arrow),
+                      ),
+                      const SizedBox(width: 10),
+                      Expanded(child: Text(dictationPlayed ? '再听一次' : '播放句子')),
+                      TextButton(
+                        onPressed: () => _play(dictation.sentence, slow: true),
+                        child: const Text('慢速'),
+                      ),
+                    ],
+                  ),
              ],
            ),
          ),
@@ -207,14 +276,34 @@ class _ReviewPageState extends State<ReviewPage> {
            controller: controller,
            minLines: 2,
            maxLines: 4,
+            enabled: dictation == null || dictationPlayed,
            onChanged: (_) => setState(() {}),
-            decoration: const InputDecoration(
-              hintText: '输入你会怎么回答',
+            decoration: InputDecoration(
+              hintText: dictation != null
+                  ? (dictationPlayed ? '写下你听到的英文' : '先播放句子')
+                  : (spokenTask ? '点下方麦克风说出来，或输入英文' : '输入你会怎么回答'),
              filled: true,
              fillColor: AppColors.surface,
-              border: OutlineInputBorder(),
+              border: const OutlineInputBorder(),
            ),
          ),
+          if (dictation == null)
+            OutlinedButton.icon(
+              onPressed: transcribing ? null : _toggleVoice,
+              icon: Icon(listening ? Icons.stop : Icons.mic_none),
+              label: Text(
+                transcribing
+                    ? '正在识别…'
+                    : listening
+                    ? '说完了，停止并识别'
+                    : '用语音回答',
+              ),
+            ),
+          if (transcript != null && controller.text.trim() != transcript)
+            Text(
+              '你修改了语音转写，本次按文字作答记录。',
+              style: TextStyle(fontSize: 12, color: AppColors.muted),
+            ),
          Wrap(
            spacing: 8,
            runSpacing: 8,
@@ -231,19 +320,14 @@ class _ReviewPageState extends State<ReviewPage> {
                label: const Text('稍后复习'),
                onPressed: () {
                  widget.state.postponeReview(item);
-                  setState(() {});
+                  setState(_resetAnswer);
                },
              ),
              ActionChip(
                label: const Text('暂时想不起来'),
                onPressed: () {
                  widget.state.reportReviewFailure(item);
-                  controller.clear();
-                  setState(() {
-                    showHint = false;
-                    usedHelp = false;
-                    validationMessage = null;
-                  });
+                  setState(_resetAnswer);
                },
              ),
              ActionChip(
@@ -262,25 +346,36 @@ class _ReviewPageState extends State<ReviewPage> {
              ActionChip(
                avatar: const Icon(Icons.search, size: 16),
                label: const Text('查词查句'),
-                onPressed: () => showLexiconLookup(
-                  context,
-                  state: widget.state,
-                ),
+                onPressed: () =>
+                    showLexiconLookup(context, state: widget.state),
              ),
            ],
          ),
          if (showHint)
            SectionCard(
              tint: AppColors.warm,
-              child: Text(
-                '参考：${item.hint}\n目标：${item.target}',
-                style: const TextStyle(color: AppColors.warmInk),
+              child: SpacedColumn(
+                spacing: 8,
+                children: [
+                  Text(
+                    dictation != null
+                        ? '句子意思：${item.hint}\n目标词句：${item.target}'
+                        : '参考：${item.hint}\n目标：${item.target}',
+                    style: TextStyle(color: AppColors.warmInk),
+                  ),
+                  if (audioText != null && dictation == null)
+                    TextButton.icon(
+                      onPressed: () => _play(audioText),
+                      icon: const Icon(Icons.volume_up_outlined),
+                      label: Text('听示范：$audioText'),
+                    ),
+                ],
              ),
            ),
          if (validationMessage != null)
            Text(
              validationMessage!,
-              style: const TextStyle(color: AppColors.warmInk),
+              style: TextStyle(color: AppColors.warmInk),
            ),
          PrimaryButton(
            label: usedHelp ? '带提示完成' : '我能独立回答',
@@ -288,7 +383,7 @@ class _ReviewPageState extends State<ReviewPage> {
                ? null
                : () => _next(item, assisted: usedHelp),
          ),
-          const Text(
+          Text(
            '提示后完成会在明天换题复练；第一次想不起来先复核，连续两次才会降低当前检查点。',
            style: TextStyle(fontSize: 12, color: AppColors.muted),
          ),
@@ -439,9 +534,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
      );
      return;
    }
-    await startVoiceInput(
-      unavailableMessage: '无法访问麦克风，请检查录音权限。你仍可输入英文完成补练。',
-    );
+    await startVoiceInput(unavailableMessage: '无法访问麦克风，请检查录音权限。你仍可输入英文完成补练。');
  }

  @override
@@ -508,7 +601,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
            Text(
              '审核：${widget.state.cachedAdaptiveLessonAuditor ?? '已配置服务'} · '
              '${_formatAuditTime(widget.state.cachedAdaptiveLessonAuditedAt!)}',
-              style: const TextStyle(color: AppColors.muted, fontSize: 12),
+              style: TextStyle(color: AppColors.muted, fontSize: 12),
            ),
          Text(task.prompt, style: Theme.of(context).textTheme.headlineMedium),
          if (showStimulus)
@@ -517,7 +610,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
              child: Text(task.stimulus, style: const TextStyle(fontSize: 20)),
            )
          else
-            const SectionCard(
+            SectionCard(
              tint: AppColors.surfaceMuted,
              child: Text('先播放音频，再输入你听到的答案。'),
            ),
@@ -579,9 +672,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
                        child: CircularProgressIndicator(strokeWidth: 2),
                      )
                    : Icon(
-                        listening
-                            ? Icons.stop_circle_outlined
-                            : Icons.mic_none,
+                        listening ? Icons.stop_circle_outlined : Icons.mic_none,
                        color: listening ? AppColors.green : null,
                      ),
              ),
@@ -639,7 +730,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
          if (answerFeedback != null)
            Text(
              answerFeedback!,
-              style: const TextStyle(color: AppColors.warmInk),
+              style: TextStyle(color: AppColors.warmInk),
            ),
          if (showReference)
            SectionCard(
@@ -121,6 +121,11 @@ class _LearningShellState extends State<LearningShell> {
    switch (route) {
      case _ShellRoute.lesson:
        body = LessonFlow(
+          // 换课或换段时重建，避免上一段的听力选择和播放状态沿用过来。
+          key: ValueKey(
+            '${widget.state.activeLessonId}-'
+            '${widget.state.activeSegmentIndexFor(widget.state.activeLessonId)}',
+          ),
          state: widget.state,
          onOpenDialogue: () => showDialogue(inLesson: true),
          onFinish: () => showTab(tab),
@@ -333,7 +338,7 @@ class _LearningMap extends StatelessWidget {
                children: [
                  Text(
                    "复习已有积压，今天先完成 ${state.dueReviewCount} 项到期复习，再开启新课。",
-                    style: const TextStyle(color: AppColors.warmInk),
+                    style: TextStyle(color: AppColors.warmInk),
                  ),
                  SecondaryButton(label: "先去复习", onPressed: onOpenReview),
                ],