diff --git a/README.md b/README.md
index 8ed9886..c00fd39 100644
--- a/README.md
+++ b/README.md
@@ -34,13 +34,13 @@
 
 原签名密钥及签名配置不改，新旧 APK 证书及公钥会核对一致。保留 `.tools/android-user/debug.keystore`，不要删除、重建或随源码分发。当前保留的证书是Android Debug类型，release运行模式不代表更换为正式发行证书；提交商店/备案前须确认目标平台是否接受。`dist/TPSchedule-signing-info.json`、证书PEM及公钥PEM只含公开签名信息。
 
-在「我的」点击「选择学校」，目前提供「电子科技大学（研究生）」。选中后应用访问 [研究生系统专用认证入口](https://yjsjy.uestc.edu.cn/pyxx/jzsso/login)，学生在学校原网页填写账号、密码和验证码；应用没有自己的密码表单，不读取或注入密码。首次认证完成后选择学校学期，确认后显示“正在查找课表，请稍候”，自动打开对应课表查询并导入保存。取消学校选择不开始登录，也不改已有课表。首次课表刷新、考试更新或更新学期共用学校选择入口；已有学校连接或学校学期时沿用原学校及学期。
+在「我的」点击「选择学校」，可选择「电子科技大学（研究生）」或「电子科技大学（本科生）」。研究生沿用[研究生系统专用认证入口](https://yjsjy.uestc.edu.cn/pyxx/jzsso/login)，认证并选择学期后自动查找课表。本科生进入[本科教务系统](https://eams.uestc.edu.cn/eams/)，自行在网页选择学期并打开课表，再点击「导入当前课表」；考试则在APP选择学期和一种或多种考试类型后自动读取。账号、密码和验证码均在学校原网页填写，应用不读取或注入密码。取消学校选择不开始登录，也不改已有课表；成功查询的学校及选项会保存在本机供刷新使用。
 
-学校目录集中在 `mobile/lib/features/school/school_selection_page.dart`，当前只列出已接入的学校。以后新增学校需增加相应认证和课表/考试解析适配，再加入目录；当前所有学校数据模型仍按电子科技大学研究生系统处理。
+学校目录集中在 `mobile/lib/features/school/school_selection_page.dart`，当前只列出已接入的学校。学校与学期有明确的来源标记，本科独立认证和解析模块位于 `mobile/lib/features/school/undergraduate/`；以后新增学校需增加相应认证和课表/考试解析适配，再加入目录。
 
-学期73为2026-2027年秋、72为2025-2026年春、71为2025-2026年秋。课表路径为 `/pyxx/pygl/xskbcx/index/{学期编号}`；考试路径为 `/pyxx/pygl/kskcxx/index?xq={学期编号}`。选择成功后保存在本机，课表右上角刷新及考试更新沿用该学期。「个人设置 → 更新学期」已连接时立即选择，未连接时先认证。读取的 HTML 必须与所选学期一致，取消或保存失败不改原数据。
+研究生学期73为2026-2027年秋、72为2025-2026年春、71为2025-2026年秋。课表路径为 `/pyxx/pygl/xskbcx/index/{学期编号}`；考试路径为 `/pyxx/pygl/kskcxx/index?xq={学期编号}`。本科学期523为2026-2027第一学期，503为2025-2026第二学期，相邻学期编号相差20；考试路径为 `/eams/stdExamTable!examTable.action?semester.id={编号}&examType.id={类型}`，类型1期末、2期中、3补考缓考。本科考试刷新沿用上次成功的学期及类型。「个人设置 → 更新学期」按所选学校进入相应流程。读取失败、取消或保存失败不改原数据。
 
-成功导入不同学期会移除另一个页面的旧学期数据并清除旧开始日，避免混用；同学期刷新保留开始日。课表页在已导入但未设置开始日时，显示课程数量及“设置学期开始日”入口，直接进入日期设置。页面标题分别为课表、考试、TPSchedule。
+研究生同源数据沿用原有跨学期更新规则；本科考试查询独立保存，不清空当前课表和学期开始日。更换课表来源或学期后需重新设置开始日，同学期刷新保留日期。课表页在已导入但未设置开始日时，显示课程数量及“设置学期开始日”入口，直接进入日期设置。页面标题分别为课表、考试、TPSchedule。
 
 专用入口的原始302响应指向 HTTP 身份认证地址，携带研究生系统的 `service` 参数。应用将该身份认证地址转到 HTTPS 并完整保留参数。学校 HTTP 回调仅允许准确的研究生系统域名。读取或保存失败保留已有数据，可在学校认证页面重试。
 
diff --git a/mobile/lib/app/app_controller.dart b/mobile/lib/app/app_controller.dart
index fb54168..1d30290 100644
--- a/mobile/lib/app/app_controller.dart
+++ b/mobile/lib/app/app_controller.dart
@@ -6,6 +6,7 @@ import '../domain/app_settings.dart';
 import '../data/snapshot_store.dart';
 import '../data/json_schedule_import.dart';
 import '../services/notification_service.dart';
+import '../services/diagnostic_log.dart';
 import '../services/calendar_service.dart';
 import '../domain/schedule_engine.dart';
 import '../data/demo_schedule.dart';
@@ -40,6 +41,10 @@ class AppController extends ChangeNotifier {
         await operation();
       } catch (error) {
         lastError = error.toString();
+        DiagnosticLog.instance.add(
+          'operation_failed',
+          fields: {'code': error.runtimeType.toString()},
+        );
       }
       notifyListeners();
     });
@@ -57,6 +62,10 @@ class AppController extends ChangeNotifier {
     await store.save(next);
     snapshot = next;
     lastError = null;
+    DiagnosticLog.instance.add(
+      'snapshot_saved',
+      fields: {'count': next.courses.length, 'term': next.schoolTerm?.id},
+    );
   }
 
   Future<void> initialize({bool reconcileServices = true}) => _run(() async {
@@ -171,6 +180,8 @@ class AppController extends ChangeNotifier {
         schoolTerm: draft.schoolTerm,
         clearExams:
             draft.schoolTerm?.school != SupportedSchool.uestcUndergraduate &&
+            snapshot.examSchedule?.school !=
+                SupportedSchool.uestcUndergraduate &&
             _differentTerm(draft.schoolTerm),
         settings: _differentTerm(draft.schoolTerm)
             ? snapshot.settings.copyWith(clearSemester: true)
@@ -359,12 +370,23 @@ class AppController extends ChangeNotifier {
         clock(),
       );
       reminderErrorCode = null;
+      DiagnosticLog.instance.add(
+        'reminders_reconciled',
+        fields: {
+          'count': occurrences.length,
+          'status': reminderResult.status.name,
+        },
+      );
     } catch (error) {
       reminderErrorCode = error is ReminderSetupException
           ? error.code
           : error is PlatformException
           ? error.code
           : error.runtimeType.toString();
+      DiagnosticLog.instance.add(
+        'reminders_failed',
+        fields: {'code': error.runtimeType.toString()},
+      );
       reminderResult = ReminderResult(
         ReminderStatus.error,
         message: error is ReminderSetupException
diff --git a/mobile/lib/domain/exam_schedule.dart b/mobile/lib/domain/exam_schedule.dart
index 6d79aa4..9d5bdea 100644
--- a/mobile/lib/domain/exam_schedule.dart
+++ b/mobile/lib/domain/exam_schedule.dart
@@ -46,6 +46,10 @@ class ExamRecord {
       return value;
     }
 
+    final typeId = json['examTypeId'];
+    if (typeId != null && (typeId is! int || typeId < 1 || typeId > 3)) {
+      throw const FormatException('考试类型无效');
+    }
     final record = ExamRecord(
       code: field('code'),
       name: field('name'),
@@ -58,7 +62,7 @@ class ExamRecord {
       date: field('date', optional: true),
       status: field('status', optional: true),
       notes: field('notes', optional: true),
-      examTypeId: json['examTypeId'] as int?,
+      examTypeId: typeId as int?,
     );
     if (record.code.isEmpty || record.name.isEmpty) {
       throw const FormatException('考试课程无效');
@@ -107,7 +111,8 @@ class ExamSchedule {
           ? SupportedSchool.uestcGraduate
           : SupportedSchool.fromId(json['schoolId'] as String);
       final rawTypes = json['requestedExamTypes'] ?? <int>[];
-      if (rawTypes is! List || rawTypes.any((t) => t is! int || t < 1 || t > 3)) {
+      if (rawTypes is! List ||
+          rawTypes.any((t) => t is! int || t < 1 || t > 3)) {
         throw const FormatException('考试类型无效');
       }
       final types = rawTypes.cast<int>().toSet();
diff --git a/mobile/lib/features/exams/exams_page.dart b/mobile/lib/features/exams/exams_page.dart
index 8d99559..0399a3c 100644
--- a/mobile/lib/features/exams/exams_page.dart
+++ b/mobile/lib/features/exams/exams_page.dart
@@ -150,11 +150,13 @@ class ExamsPage extends StatelessWidget {
             style: TextStyle(fontSize: 13, color: ink.withValues(alpha: 0.55)),
           ),
           const SizedBox(height: 18),
-          if (schedule.school == SupportedSchool.uestcUndergraduate)
+          if (schedule.school == SupportedSchool.uestcUndergraduate) ...[
             Text(
               '查询类型：${UndergraduateExamQuery.fromSchedule(schedule)!.orderedTypes.map((t) => t.label).join('、')}',
               style: const TextStyle(fontSize: 12),
             ),
+            const SizedBox(height: 16),
+          ],
           if (schedule.records.isEmpty)
             Text(
               schedule.school == SupportedSchool.uestcUndergraduate
diff --git a/mobile/lib/features/feedback/feedback_http_sender.dart b/mobile/lib/features/feedback/feedback_http_sender.dart
index 757484e..17658d5 100644
--- a/mobile/lib/features/feedback/feedback_http_sender.dart
+++ b/mobile/lib/features/feedback/feedback_http_sender.dart
@@ -192,6 +192,14 @@ class HttpFeedbackSender implements FeedbackSender {
       bytes.add(attachment.bytes);
       write('\r\n');
     }
+    if (submission.diagnosticLog != null) {
+      write(
+        '--$boundary\r\nContent-Disposition: form-data; name="diagnostics"; filename="TPSchedule-diagnostics.txt"\r\n'
+        'Content-Type: text/plain; charset=utf-8\r\n\r\n',
+      );
+      bytes.add(submission.diagnosticLog!);
+      write('\r\n');
+    }
     write('--$boundary--\r\n');
     return bytes.takeBytes();
   }
diff --git a/mobile/lib/features/feedback/feedback_page.dart b/mobile/lib/features/feedback/feedback_page.dart
index a764aec..c945f37 100644
--- a/mobile/lib/features/feedback/feedback_page.dart
+++ b/mobile/lib/features/feedback/feedback_page.dart
@@ -2,6 +2,7 @@ import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 
 import '../../app/app_theme.dart';
+import '../../services/diagnostic_log.dart';
 import 'feedback_submission.dart';
 
 typedef FeedbackAttachmentPicker = Future<FeedbackAttachment?> Function();
@@ -32,6 +33,7 @@ class _FeedbackPageState extends State<FeedbackPage> {
   var _picking = false;
   var _success = false;
   var _uncertain = false;
+  var _includeLogs = false;
   String? _error;
   FeedbackSubmission? _pendingSubmission;
 
@@ -103,6 +105,7 @@ class _FeedbackPageState extends State<FeedbackPage> {
     if (_submitting || _picking) return;
     if (!_uncertain && !(_form.currentState?.validate() ?? false)) return;
     FocusScope.of(context).unfocus();
+    setState(() => _submitting = true);
     try {
       _pendingSubmission ??= _kind == FeedbackKind.problem
           ? FeedbackSubmission.problem(
@@ -111,6 +114,9 @@ class _FeedbackPageState extends State<FeedbackPage> {
               contact: _contact.text,
               attachments: _attachments,
               limits: widget.limits,
+              diagnosticLog: _includeLogs
+                  ? await DiagnosticLog.instance.export()
+                  : null,
             )
           : FeedbackSubmission.development(
               id: FeedbackSubmission.newId(),
@@ -256,6 +262,24 @@ class _FeedbackPageState extends State<FeedbackPage> {
                               : null,
                         ),
                         if (_kind == FeedbackKind.problem) ...[
+                          CheckboxListTile(
+                            key: const Key('feedback-logs'),
+                            contentPadding: EdgeInsets.zero,
+                            title: const Text('附带近10分钟诊断日志'),
+                            subtitle: const Text(
+                              '包含登录跳转、课表读取及错误状态，帮助排查问题；不包含密码、验证码或课表内容。',
+                            ),
+                            value: _includeLogs,
+                            onChanged: _submitting
+                                ? null
+                                : (value) {
+                                    setState(() {
+                                      _includeLogs = value ?? false;
+                                      _pendingSubmission = null;
+                                      _error = null;
+                                    });
+                                  },
+                          ),
                           const SizedBox(height: 10),
                           const Text(
                             '图片或视频（选填）',
diff --git a/mobile/lib/features/feedback/feedback_submission.dart b/mobile/lib/features/feedback/feedback_submission.dart
index 51210aa..73f3931 100644
--- a/mobile/lib/features/feedback/feedback_submission.dart
+++ b/mobile/lib/features/feedback/feedback_submission.dart
@@ -102,6 +102,7 @@ class FeedbackSubmission {
     this.contact,
     this.school,
     this.attachments = const [],
+    this.diagnosticLog,
   });
 
   factory FeedbackSubmission.problem({
@@ -110,18 +111,26 @@ class FeedbackSubmission {
     String? contact,
     List<FeedbackAttachment> attachments = const [],
     FeedbackLimits limits = FeedbackLimits.defaults,
+    Uint8List? diagnosticLog,
   }) {
     final text = message.trim();
     if (text.isEmpty) throw const FeedbackException('请填写问题或建议');
     if (text.length > 5000) throw const FeedbackException('问题或建议不能超过 5000 个字符');
     _validateContact(contact);
     validateAttachments(attachments, limits);
+    if (diagnosticLog != null &&
+        (diagnosticLog.isEmpty || diagnosticLog.length > 256 * 1024)) {
+      throw const FeedbackException('日志附件不能超过256 KB');
+    }
     return FeedbackSubmission._(
       id: id,
       kind: FeedbackKind.problem,
       message: text,
       contact: _optional(contact),
       attachments: List.unmodifiable(attachments),
+      diagnosticLog: diagnosticLog == null
+          ? null
+          : Uint8List.fromList(diagnosticLog).asUnmodifiableView(),
     );
   }
 
@@ -151,6 +160,7 @@ class FeedbackSubmission {
   final String? contact;
   final String? school;
   final List<FeedbackAttachment> attachments;
+  final Uint8List? diagnosticLog;
 
   static String newId() {
     final random = Random.secure();
diff --git a/mobile/lib/features/school/school_session.dart b/mobile/lib/features/school/school_session.dart
index 357d464..f74c1a4 100644
--- a/mobile/lib/features/school/school_session.dart
+++ b/mobile/lib/features/school/school_session.dart
@@ -6,6 +6,7 @@ import 'package:webview_flutter/webview_flutter.dart';
 import '../../data/json_schedule_import.dart';
 import '../../domain/exam_schedule.dart';
 import '../../domain/school_term.dart';
+import '../../services/diagnostic_log.dart';
 import 'school_navigation_policy.dart';
 import 'school_page_adapter.dart';
 import 'school_exam_adapter.dart';
@@ -40,7 +41,10 @@ class SchoolSession extends ChangeNotifier {
               await web.loadRequest(upgrade);
             } catch (_) {
               if (generation == _pageGeneration) {
-                _failure('学校身份认证暂时无法打开，请重试。');
+                _failure(
+                  '学校身份认证暂时无法打开，请重试。',
+                  code: 'authentication_load_failed',
+                );
               }
             }
             return NavigationDecision.prevent;
@@ -55,12 +59,15 @@ class SchoolSession extends ChangeNotifier {
                 'Blocked school navigation origin: ${uri?.scheme}://${uri?.host}',
               );
             }
-            if (request.isMainFrame) _failure('学校跳转到了其他地址，请返回学校认证入口重试。');
+            if (request.isMainFrame) {
+              _failure('学校跳转到了其他地址，请返回学校认证入口重试。', code: 'blocked_navigation');
+            }
             return NavigationDecision.prevent;
           }
           return NavigationDecision.navigate;
         },
-        onPageStarted: (_) {
+        onPageStarted: (url) {
+          DiagnosticLog.instance.navigation('graduate', 'started', url);
           _poll?.cancel();
           _manualRead = false;
           _pageGeneration++;
@@ -79,7 +86,11 @@ class SchoolSession extends ChangeNotifier {
           if (hasOpened &&
               generation == _pageGeneration &&
               error.url == current) {
-            _failure('学校页面暂时未能加载，请检查网络后重试。');
+            _failure(
+              '学校页面暂时未能加载，请检查网络后重试。',
+              code: 'web_resource_error',
+              status: error.errorCode,
+            );
           }
         },
         onHttpError: (error) async {
@@ -89,7 +100,11 @@ class SchoolSession extends ChangeNotifier {
               generation == _pageGeneration &&
               error.request != null &&
               error.request!.uri == current) {
-            _failure('学校请求未完成，请稍后重试。');
+            _failure(
+              '学校请求未完成，请稍后重试。',
+              code: 'http_error',
+              status: error.response?.statusCode,
+            );
           }
         },
       ),
@@ -175,6 +190,14 @@ class SchoolSession extends ChangeNotifier {
     bool forceAuth = false,
   }) async {
     final serial = ++_openSerial;
+    DiagnosticLog.instance.add(
+      'login_opened',
+      fields: {
+        'school': 'graduate',
+        'phase': exams ? 'exams' : 'timetable',
+        'term': term?.id,
+      },
+    );
     final closing = _logoutFuture;
     if (closing != null) await closing;
     if (serial != _openSerial) return;
@@ -211,7 +234,7 @@ class SchoolSession extends ChangeNotifier {
       await web.loadRequest(connected ? _target : authUrl);
     } catch (_) {
       if (serial == _openSerial && generation == _pageGeneration) {
-        _failure('学校入口无法打开，请检查校园网络后重试。');
+        _failure('学校入口无法打开，请检查校园网络后重试。', code: 'entry_load_failed');
       }
     }
   }
@@ -244,7 +267,7 @@ class SchoolSession extends ChangeNotifier {
       await web.loadRequest(_target);
     } catch (_) {
       if (serial == _openSerial && generation == _pageGeneration) {
-        _failure('学校学期查询页面暂时无法打开，请重试。');
+        _failure('学校学期查询页面暂时无法打开，请重试。', code: 'query_load_failed');
       }
     }
   }
@@ -254,11 +277,20 @@ class SchoolSession extends ChangeNotifier {
     _timeout?.cancel();
     _timeout = Timer(
       const Duration(seconds: 45),
-      () => _failure('查找超时，请检查学校页面后重试。已有数据保持不变。'),
+      () => _failure('查找超时，请检查学校页面后重试。已有数据保持不变。', code: 'read_timeout'),
     );
   }
 
-  void _failure(String text) {
+  void _failure(String text, {String code = 'flow_failure', int? status}) {
+    DiagnosticLog.instance.add(
+      'school_read_failed',
+      fields: {
+        'school': 'graduate',
+        'code': code,
+        'status': status,
+        'term': selectedTerm?.id,
+      },
+    );
     if (!hasOpened || _routeClosed) return;
     _pageGeneration++;
     _reader.invalidate();
@@ -305,7 +337,7 @@ class SchoolSession extends ChangeNotifier {
     }
     _poll?.cancel();
     if (_pollsLeft-- <= 0) {
-      if (finding) _failure('查找超时，请检查学校页面后重试。已有数据保持不变。');
+      if (finding) _failure('查找超时，请检查学校页面后重试。已有数据保持不变。', code: 'read_timeout');
       return;
     }
     _poll = Timer(const Duration(milliseconds: 750), () {
@@ -320,6 +352,9 @@ class SchoolSession extends ChangeNotifier {
       );
 
   Future<void> _loaded(String url, {bool resetPolling = true}) async {
+    if (resetPolling) {
+      DiagnosticLog.instance.navigation('graduate', 'finished', url);
+    }
     if (!hasOpened || _routeClosed) return;
     final generation = _pageGeneration;
     final uri = Uri.tryParse(url);
@@ -360,6 +395,15 @@ class SchoolSession extends ChangeNotifier {
     }
     try {
       final evidence = await _evidence(uri);
+      DiagnosticLog.instance.add(
+        'school_evidence',
+        fields: {
+          'school': 'graduate',
+          'result': evidence.authenticated,
+          'count': evidence.pages.length,
+          'term': selectedTerm?.id,
+        },
+      );
       if (!hasOpened ||
           generation != _pageGeneration ||
           await web.currentUrl() != url) {
@@ -384,14 +428,26 @@ class SchoolSession extends ChangeNotifier {
           if (requestingExams) {
             final draft = SchoolExamAdapter.extract(page.html);
             if (generation != _pageGeneration) return;
-            if (draft.termId != selectedTerm?.id.toString()) continue;
+            if (draft.termId != selectedTerm?.id.toString()) {
+              DiagnosticLog.instance.add(
+                'term_mismatch',
+                fields: {'school': 'graduate'},
+              );
+              continue;
+            }
             pendingExams = draft;
           } else {
             // The probe validates the live document's origin. The strict parser
             // gets only its recognized fragment with the canonical table path.
             final draft = await _reader.read(_target, () async => page.html);
             if (!hasOpened || generation != _pageGeneration) return;
-            if (draft.schoolTerm != selectedTerm) continue;
+            if (draft.schoolTerm != selectedTerm) {
+              DiagnosticLog.instance.add(
+                'term_mismatch',
+                fields: {'school': 'graduate'},
+              );
+              continue;
+            }
             pendingDraft = draft;
           }
           _timeout?.cancel();
@@ -399,9 +455,27 @@ class SchoolSession extends ChangeNotifier {
           connectionState = SchoolConnectionState.connected;
           finding = true;
           message = '读取成功，正在保存…';
+          DiagnosticLog.instance.add(
+            'school_parsed',
+            fields: {
+              'school': 'graduate',
+              'phase': requestingExams ? 'exams' : 'timetable',
+              'count':
+                  pendingDraft?.courses.length ??
+                  pendingExams?.records.length ??
+                  0,
+            },
+          );
           notifyListeners();
           return;
-        } catch (_) {
+        } catch (error) {
+          DiagnosticLog.instance.add(
+            'school_parse_rejected',
+            fields: {
+              'school': 'graduate',
+              'code': error.runtimeType.toString(),
+            },
+          );
           if (generation != _pageGeneration) return;
           // A recognized table can still be incomplete during asynchronous load.
         }
@@ -411,6 +485,14 @@ class SchoolSession extends ChangeNotifier {
           ? null
           : _flow.onLoaded(uri, authenticated: evidence.authenticated);
       if (next != null) {
+        DiagnosticLog.instance.add(
+          'school_redirect_requested',
+          fields: {
+            'school': 'graduate',
+            'phase': requestingExams ? 'exams' : 'timetable',
+            'term': selectedTerm?.id,
+          },
+        );
         finding = true;
         _loading = true;
         message = _findingMessage;
@@ -420,14 +502,17 @@ class SchoolSession extends ChangeNotifier {
           await web.loadRequest(next);
         } catch (_) {
           if (generation == _pageGeneration) {
-            _failure('课表查询页面暂时无法打开，请重试。');
+            _failure('课表查询页面暂时无法打开，请重试。', code: 'query_load_failed');
           }
         }
         return;
       }
       if (!finding) message = '请在学校网页完成认证；进入研究生系统后会自动读取。';
-    } catch (_) {
-      // JavaScript and frame access can fail briefly while the page is changing.
+    } catch (error) {
+      DiagnosticLog.instance.add(
+        'school_probe_failed',
+        fields: {'school': 'graduate', 'code': error.runtimeType.toString()},
+      );
     } finally {
       if (_probeGeneration == generation) _probeGeneration = null;
       _scheduleProbe(url, generation);
diff --git a/mobile/lib/features/school/undergraduate/activity_data.dart b/mobile/lib/features/school/undergraduate/activity_data.dart
index ad3379a..dd67090 100644
--- a/mobile/lib/features/school/undergraduate/activity_data.dart
+++ b/mobile/lib/features/school/undergraduate/activity_data.dart
@@ -21,6 +21,10 @@ List<UndergraduateActivity> parseActivityData(
     r'new\s+TaskActivity\s*\((.*?)\)\s*;',
     dotAll: true,
   ).allMatches(script).toList();
+  if (RegExp(r'\bnew\s+TaskActivity\s*\(').allMatches(script).length !=
+      matches.length) {
+    throw const FormatException('课程活动声明不完整');
+  }
   final result = <UndergraduateActivity>[];
   for (var i = 0; i < matches.length; i++) {
     final m = matches[i], args = _strings(m[1]!);
@@ -48,9 +52,17 @@ List<UndergraduateActivity> parseActivityData(
     final assignments = RegExp(r'\bindex\s*=\s*([^;]+);')
         .allMatches(body)
         .toList();
-    final appends = RegExp(
+    final appendPattern = RegExp(
       r'table\d+\.activities\[index\]\s*\[[^;]+?\]\s*=\s*activity\s*;',
-    ).allMatches(body).length;
+    );
+    final appends = appendPattern.allMatches(body).length;
+    final unconsumed = body
+        .replaceAll(appendPattern, '')
+        .replaceAll(RegExp(r'\bindex\s*=\s*[^;]+;'), '');
+    if (RegExp(r'\btable\d+\.activities\s*\[|\bindex\s*=')
+        .hasMatch(unconsumed)) {
+      throw const FormatException('存在无法识别的课程节次赋值');
+    }
     if (assignments.isEmpty || assignments.length != appends) {
       throw const FormatException('课程节次赋值不完整');
     }
diff --git a/mobile/lib/features/school/undergraduate/session.dart b/mobile/lib/features/school/undergraduate/session.dart
index a05ea10..0d2873f 100644
--- a/mobile/lib/features/school/undergraduate/session.dart
+++ b/mobile/lib/features/school/undergraduate/session.dart
@@ -6,6 +6,7 @@ import 'package:webview_flutter/webview_flutter.dart';
 import '../../../data/json_schedule_import.dart';
 import '../../../domain/exam_schedule.dart';
 import '../../../domain/undergraduate_exam_query.dart';
+import '../../../services/diagnostic_log.dart';
 import 'navigation_policy.dart';
 import 'page_probe.dart';
 import 'timetable_adapter.dart';
@@ -98,7 +99,9 @@ class UndergraduateSession extends ChangeNotifier {
                 uri,
                 isMainFrame: request.isMainFrame,
               )) {
-            if (request.isMainFrame) _failure('学校跳转未完成，请重新认证。');
+            if (request.isMainFrame) {
+              _failure('学校跳转未完成，请重新认证。', code: 'blocked_navigation');
+            }
             return NavigationDecision.prevent;
           }
           if (request.isMainFrame &&
@@ -107,7 +110,13 @@ class UndergraduateSession extends ChangeNotifier {
           }
           return NavigationDecision.navigate;
         },
-        onPageStarted: (_) {
+        onPageStarted: (url) {
+          DiagnosticLog.instance.navigation('undergraduate', 'started', url);
+          // Within a batch, type-to-type loads retain their generation. Once
+          // published, any new document invalidates the deferred save result.
+          if (pendingExams != null) {
+            _reset();
+          }
           _document++;
           _poll?.cancel();
           _probeKey = null;
@@ -125,7 +134,11 @@ class UndergraduateSession extends ChangeNotifier {
               d = _document,
               current = await web.currentUrl();
           if (_valid(g) && d == _document && error.url == current) {
-            _failure('学校页面加载未完成，请检查网络后重试。');
+            _failure(
+              '学校页面加载未完成，请检查网络后重试。',
+              code: 'web_resource_error',
+              status: error.errorCode,
+            );
           }
         },
         onHttpError: (error) async {
@@ -135,12 +148,20 @@ class UndergraduateSession extends ChangeNotifier {
           if (_valid(g) &&
               d == _document &&
               error.request?.uri.toString() == current) {
-            _failure('学校请求未完成，请稍后重试。');
+            _failure(
+              '学校请求未完成，请稍后重试。',
+              code: 'http_error',
+              status: error.response?.statusCode,
+            );
           }
         },
       ),
     );
   Future<void> openTimetable() async {
+    DiagnosticLog.instance.add(
+      'login_opened',
+      fields: {'school': 'undergraduate', 'phase': 'timetable'},
+    );
     await _logoutFuture;
     if (_disposed) return;
     _reset();
@@ -153,6 +174,14 @@ class UndergraduateSession extends ChangeNotifier {
   }
 
   Future<void> openExams(UndergraduateExamQuery value) async {
+    DiagnosticLog.instance.add(
+      'login_opened',
+      fields: {
+        'school': 'undergraduate',
+        'phase': 'exams',
+        'term': value.term.id,
+      },
+    );
     await _logoutFuture;
     if (_disposed) return;
     _reset();
@@ -196,7 +225,16 @@ class UndergraduateSession extends ChangeNotifier {
     }
   }
 
-  void _failure(String text) {
+  void _failure(String text, {String code = 'read_failure', int? status}) {
+    DiagnosticLog.instance.add(
+      'school_read_failed',
+      fields: {
+        'school': 'undergraduate',
+        'code': code,
+        'status': status,
+        'term': query?.term.id,
+      },
+    );
     if (_disposed) return;
     _reset();
     _failed = true;
@@ -233,6 +271,7 @@ class UndergraduateSession extends ChangeNotifier {
         uri,
       );
   Future<void> _loaded(String url) async {
+    DiagnosticLog.instance.navigation('undergraduate', 'finished', url);
     final g = _generation, d = _document, key = '$_generation:$_document';
     if (!_valid(g) || _failed || _complete || _probeKey == key) return;
     _probeKey = key;
@@ -245,6 +284,14 @@ class UndergraduateSession extends ChangeNotifier {
         return;
       }
       final status = await _evidence(uri, false);
+      DiagnosticLog.instance.add(
+        'school_evidence',
+        fields: {
+          'school': 'undergraduate',
+          'result': status.authenticated,
+          'count': status.pages.length,
+        },
+      );
       if (!_valid(g) || d != _document) return;
       _loading = false;
       if (!status.authenticated) {
@@ -283,6 +330,14 @@ class UndergraduateSession extends ChangeNotifier {
       _itemTimeout = null;
       if (_index == query!.orderedTypes.length) {
         pendingExams = UndergraduateExamAdapter.merge(query!, _parts);
+        DiagnosticLog.instance.add(
+          'school_parsed',
+          fields: {
+            'school': 'undergraduate',
+            'phase': 'exams',
+            'count': pendingExams!.records.length,
+          },
+        );
         _complete = true;
         _cancelTimers();
         message = '考试已全部读取，正在保存…';
@@ -291,7 +346,9 @@ class UndergraduateSession extends ChangeNotifier {
         await _requestExam(g);
       }
     } catch (error) {
-      if (_valid(g) && d == _document) _failure('$error');
+      if (_valid(g) && d == _document) {
+        _failure('$error', code: error.runtimeType.toString());
+      }
     } finally {
       if (_probeKey == key) _probeKey = null;
     }
@@ -300,16 +357,24 @@ class UndergraduateSession extends ChangeNotifier {
   Future<void> _requestExam(int g) async {
     if (!_valid(g) || query == null || _complete) return;
     final type = query!.orderedTypes[_index];
+    DiagnosticLog.instance.add(
+      'school_read_requested',
+      fields: {
+        'school': 'undergraduate',
+        'term': query!.term.id,
+        'type': type.id,
+      },
+    );
     _expected = query!.uriFor(type);
     _loading = true;
     message = '正在读取${type.label}（${_index + 1}/${query!.types.length}）';
     _emit();
     _itemTimeout?.cancel();
     _itemTimeout = Timer(const Duration(seconds: 45), () {
-      if (_valid(g)) _failure('${type.label}读取超时，请重试。');
+      if (_valid(g)) _failure('${type.label}读取超时，请重试。', code: 'item_timeout');
     });
     _batchTimeout ??= Timer(const Duration(seconds: 120), () {
-      if (_valid(g)) _failure('考试读取超时，请重试。');
+      if (_valid(g)) _failure('考试读取超时，请重试。', code: 'batch_timeout');
     });
     await _navigate(_expected!);
   }
diff --git a/mobile/lib/main.dart b/mobile/lib/main.dart
index addf1e7..56caaba 100644
--- a/mobile/lib/main.dart
+++ b/mobile/lib/main.dart
@@ -5,6 +5,8 @@ import 'package:path_provider/path_provider.dart';
 import 'package:timezone/data/latest.dart' as tzdata;
 
 import 'app/app_controller.dart';
+import 'app/app_version.dart';
+import 'services/diagnostic_log.dart';
 import 'app/hepan_app.dart';
 import 'app/tp_startup.dart';
 import 'data/file_snapshot_store.dart';
@@ -37,6 +39,7 @@ Widget buildApplication(
 );
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  DiagnosticLog.instance.add('app_started', fields: {'version': appVersion});
   AppController? controller;
   await launchApplication(
     bootstrap: () async {
@@ -45,8 +48,10 @@ Future<void> main() async {
       final gateway = PluginReminderGateway(
         onTap: (key) => selection.value = key,
       );
+      final directory = await getApplicationSupportDirectory();
+      unawaited(DiagnosticLog.instance.attach(directory));
       final value = AppController(
-        FileSnapshotStore(await getApplicationSupportDirectory()),
+        FileSnapshotStore(directory),
         LocalNotificationService(gateway),
         AndroidCalendarService(MethodCalendarGateway()),
         DateTime.now,
diff --git a/mobile/lib/services/diagnostic_log.dart b/mobile/lib/services/diagnostic_log.dart
new file mode 100644
index 0000000..c27b013
--- /dev/null
+++ b/mobile/lib/services/diagnostic_log.dart
@@ -0,0 +1,156 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'dart:typed_data';
+
+/// Small, structured breadcrumbs. Never accepts raw URLs, HTML or exceptions.
+class DiagnosticLog {
+  DiagnosticLog({DateTime Function()? clock}) : clock = clock ?? DateTime.now;
+  static final instance = DiagnosticLog();
+  static const maxBytes = 256 * 1024;
+  static const _keys = {
+    'school',
+    'phase',
+    'page',
+    'count',
+    'term',
+    'type',
+    'status',
+    'code',
+    'version',
+    'result',
+  };
+  final DateTime Function() clock;
+  final _entries = <Map<String, dynamic>>[];
+  File? _file;
+  Future<void> _writes = Future.value();
+  Timer? _timer;
+
+  Map<String, Object> _safe(Map fields) => {
+    for (final e in fields.entries.take(6))
+      if (_keys.contains(e.key) &&
+          (e.value is bool ||
+              e.value is int ||
+              e.value is String &&
+                  RegExp(r'^[A-Za-z0-9_.-]{1,40}$').hasMatch(e.value)))
+        e.key as String: e.value as Object,
+  };
+  void _trim() {
+    final now = clock().toUtc();
+    _entries.removeWhere((e) {
+      final at = DateTime.tryParse(e['at'] as String? ?? '');
+      return at == null ||
+          at.isAfter(now) ||
+          now.difference(at) > const Duration(minutes: 10);
+    });
+    if (_entries.length > 500) _entries.removeRange(0, _entries.length - 500);
+  }
+
+  void add(String event, {Map<String, Object?> fields = const {}}) {
+    if (!RegExp(r'^[a-z_]{1,64}$').hasMatch(event)) return;
+    _trim();
+    final safe = _safe(fields);
+    if (_entries.isNotEmpty) {
+      final last = _entries.last;
+      final at = DateTime.tryParse(last['at'] as String? ?? '');
+      final previous = Map<String, dynamic>.from(last)
+        ..remove('at')
+        ..remove('event');
+      if (last['event'] == event &&
+          jsonEncode(previous) == jsonEncode(safe) &&
+          at != null &&
+          clock().toUtc().difference(at) < const Duration(seconds: 3)) {
+        return;
+      }
+    }
+    _entries.add({
+      'at': clock().toUtc().toIso8601String(),
+      'event': event,
+      ...safe,
+    });
+    _trim();
+    unawaited(flush());
+  }
+
+  void navigation(String school, String phase, String url) {
+    final uri = Uri.tryParse(url);
+    final page = uri == null
+        ? 'unknown'
+        : uri.host == 'idas.uestc.edu.cn'
+        ? 'identity'
+        : uri.host == 'yjsjy.uestc.edu.cn'
+        ? uri.path.contains('xskbcx')
+              ? 'timetable'
+              : uri.path.contains('kskcxx')
+              ? 'exams'
+              : 'graduate_portal'
+        : uri.host == 'eams.uestc.edu.cn'
+        ? uri.path.contains('stdExamTable')
+              ? 'exams'
+              : uri.path.contains('courseTable')
+              ? 'timetable'
+              : 'undergraduate_portal'
+        : 'external';
+    add('navigation_$phase', fields: {'school': school, 'page': page});
+  }
+
+  Future<void> attach(Directory directory) async {
+    final file = File('${directory.path}/diagnostics-recent.json');
+    try {
+      if (await file.exists() && await file.length() <= maxBytes) {
+        final saved = jsonDecode(await file.readAsString());
+        if (saved is List) {
+          final restored = <Map<String, dynamic>>[];
+          for (final row in saved.take(500)) {
+            if (row is Map &&
+                row['at'] is String &&
+                row['event'] is String &&
+                RegExp(r'^[a-z_]{1,64}$').hasMatch(row['event'])) {
+              restored.add({
+                'at': row['at'],
+                'event': row['event'],
+                ..._safe(row),
+              });
+            }
+          }
+          _entries.insertAll(0, restored);
+        }
+      }
+    } catch (_) {
+      /* Diagnostics must never block startup or feedback. */
+    }
+    _file = file;
+    _timer?.cancel();
+    _timer = Timer.periodic(
+      const Duration(minutes: 1),
+      (_) => unawaited(flush()),
+    );
+    await flush();
+  }
+
+  Future<void> flush() {
+    _trim();
+    final file = _file;
+    if (file == null) return Future.value();
+    final text = jsonEncode(_entries);
+    _writes = _writes.then((_) async {
+      try {
+        await file.writeAsString(text, flush: true);
+      } catch (_) {}
+    });
+    return _writes;
+  }
+
+  Future<Uint8List> export() async {
+    _trim();
+    await flush();
+    final header =
+        'TPSchedule diagnostic log\nWindow: last 10 minutes (UTC timestamps)\n'
+        'Up to 500 recent events; no passwords, cookies, HTML or feedback text.\n';
+    return Uint8List.fromList(
+      utf8.encode('$header${_entries.map(jsonEncode).join('\n')}\n'),
+    );
+  }
+
+  void dispose() => _timer?.cancel();
+}
diff --git a/mobile/test/app/undergraduate_controller_test.dart b/mobile/test/app/undergraduate_controller_test.dart
index ed133cc..050f3c4 100644
--- a/mobile/test/app/undergraduate_controller_test.dart
+++ b/mobile/test/app/undergraduate_controller_test.dart
@@ -109,4 +109,24 @@ void main() {
         '{"schemaVersion":1,"courses":[${const JsonEncoder().convert(old)}]}';
     expect(() => JsonScheduleImport.parse(json), throwsFormatException);
   });
+  test('graduate timetable changes preserve independently saved undergraduate exams', () async {
+    await controller.initialize();
+    await controller.applyExams(exams());
+    await controller.applyImport(
+      ImportDraft(
+        courses: [course()],
+        explicitlyEmpty: false,
+        source: course().source,
+        parserVersion: 'test',
+        schoolTerm: SchoolTerm(72),
+      ),
+      confirmedEmpty: false,
+    );
+    expect(controller.lastError, isNull);
+    expect(
+      controller.snapshot.examSchedule?.school,
+      SupportedSchool.uestcUndergraduate,
+    );
+    expect(controller.snapshot.examSchedule?.termId, '503');
+  });
 }
diff --git a/mobile/test/domain/undergraduate_models_test.dart b/mobile/test/domain/undergraduate_models_test.dart
index 2c0199c..9a07cc9 100644
--- a/mobile/test/domain/undergraduate_models_test.dart
+++ b/mobile/test/domain/undergraduate_models_test.dart
@@ -7,6 +7,17 @@ import 'package:hepan_everyday/domain/app_snapshot.dart';
 import 'package:hepan_everyday/domain/course.dart';
 
 void main() {
+  test(
+    'optional exam types reject invalid values even in graduate snapshots',
+    () {
+      final saved = ExamSchedule(
+        semesterLabel: '2026秋',
+        termId: '73',
+        records: [const ExamRecord(code: 'A', name: '课程', examTypeId: 99)],
+      ).toJson();
+      expect(() => ExamSchedule.fromJson(saved), throwsFormatException);
+    },
+  );
   test(
     'managed undergraduate identifiers cannot lose their school or term',
     () {
diff --git a/mobile/test/features/feedback_http_sender_test.dart b/mobile/test/features/feedback_http_sender_test.dart
index 6e86b13..411540b 100644
--- a/mobile/test/features/feedback_http_sender_test.dart
+++ b/mobile/test/features/feedback_http_sender_test.dart
@@ -33,6 +33,27 @@ class FakeFeedbackHttpTransport implements FeedbackHttpTransport {
 }
 
 void main() {
+  test('diagnostics use a separate UTF8 attachment field', () async {
+    final transport = FakeFeedbackHttpTransport();
+    await HttpFeedbackSender(
+      endpoint: 'https://example.com/v1/feedback',
+      transport: transport,
+    ).send(
+      FeedbackSubmission.problem(
+        id: 'same-id',
+        message: '问题',
+        diagnosticLog: Uint8List.fromList(
+          utf8.encode('TPSchedule diagnostic log\nlogin_opened'),
+        ),
+      ),
+    );
+    final body = utf8.decode(transport.body!);
+    expect(
+      body,
+      contains('name="diagnostics"; filename="TPSchedule-diagnostics.txt"'),
+    );
+    expect(body, contains('login_opened'));
+  });
   test(
     'matching uncertain delivery is distinct and never exposes server detail',
     () async {
diff --git a/mobile/test/features/feedback_test.dart b/mobile/test/features/feedback_test.dart
index 64570f2..bc72c31 100644
--- a/mobile/test/features/feedback_test.dart
+++ b/mobile/test/features/feedback_test.dart
@@ -31,10 +31,29 @@ Future<void> reveal(
     backwards ? -250 : 250,
     scrollable: find.byType(Scrollable).first,
   );
-  await tester.pump();
+  await tester.pumpAndSettle();
 }
 
 void main() {
+  testWidgets('logs are opt in and included only when checked', (tester) async {
+    final sender = RecordingSender();
+    await tester.pumpWidget(MaterialApp(home: FeedbackPage(sender: sender)));
+    await tester.enterText(find.byKey(const Key('feedback-message')), '无法登录');
+    await reveal(tester, find.byKey(const Key('feedback-logs')));
+    expect(
+      tester
+          .widget<CheckboxListTile>(find.byKey(const Key('feedback-logs')))
+          .value,
+      isFalse,
+    );
+    await tester.tap(find.byKey(const Key('feedback-logs')));
+    await tester.pump();
+    await reveal(tester, find.byKey(const Key('feedback-submit')));
+    await tester.tap(find.byKey(const Key('feedback-submit')));
+    await tester.pumpAndSettle();
+    expect(sender.submissions.single.diagnosticLog, isNotNull);
+    expect(sender.submissions.single.attachments, isEmpty);
+  });
   testWidgets('uncertain delivery retains original payload for status check', (
     tester,
   ) async {
@@ -191,7 +210,7 @@ void main() {
       ),
     );
     await tester.enterText(find.byKey(const Key('feedback-message')), '旧问题');
-    await tester.ensureVisible(find.byKey(const Key('feedback-add-media')));
+    await reveal(tester, find.byKey(const Key('feedback-add-media')));
     await tester.tap(find.byKey(const Key('feedback-add-media')));
     await tester.pumpAndSettle();
     await reveal(tester, find.text('我要参与开发'), backwards: true);
@@ -303,7 +322,7 @@ void main() {
       ),
     );
     await tester.enterText(find.byKey(const Key('feedback-message')), '问题');
-    await tester.ensureVisible(find.byKey(const Key('feedback-add-media')));
+    await reveal(tester, find.byKey(const Key('feedback-add-media')));
     await tester.tap(find.byKey(const Key('feedback-add-media')));
     await tester.pumpAndSettle();
     expect(find.text('screen.png'), findsOneWidget);
@@ -312,7 +331,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(sender.submissions.single.attachments, hasLength(1));
     expect(find.text('screen.png'), findsOneWidget);
-    await tester.ensureVisible(find.byTooltip('移除 screen.png'));
+    await reveal(tester, find.byTooltip('移除 screen.png'), backwards: true);
     await tester.tap(find.byTooltip('移除 screen.png'));
     await tester.pumpAndSettle();
     expect(find.text('screen.png'), findsNothing);
diff --git a/mobile/test/school/school_session_flow_test.dart b/mobile/test/school/school_session_flow_test.dart
index f418a4b..b1883ea 100644
--- a/mobile/test/school/school_session_flow_test.dart
+++ b/mobile/test/school/school_session_flow_test.dart
@@ -1,4 +1,7 @@
 import 'dart:async';
+import 'dart:convert';
+
+import 'package:hepan_everyday/services/diagnostic_log.dart';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:webview_flutter_platform_interface/webview_flutter_platform_interface.dart';
@@ -26,6 +29,30 @@ void main() {
     platform.delegate.finished(url);
   }
 
+  test('login diagnostic breadcrumbs distinguish probe and network failures without raw details', () async {
+    await session.openTimetable(term: SchoolTerm(73));
+    session.setReadingActive(true);
+    platform.web.javascript = (_) async => throw StateError('PRIVATE_TICKET');
+    navigate('https://yjsjy.uestc.edu.cn/pyxx/home/index');
+    await flushSchoolEvents();
+    var log = utf8.decode(await DiagnosticLog.instance.export());
+    expect(log, contains('school_probe_failed'));
+    expect(log, isNot(contains('PRIVATE_TICKET')));
+    platform.delegate.resourceError(
+      WebResourceError(
+        errorCode: -2,
+        description: 'PRIVATE_NETWORK_DETAIL',
+        isForMainFrame: true,
+        url: platform.web.url,
+      ),
+    );
+    await flushSchoolEvents();
+    log = utf8.decode(await DiagnosticLog.instance.export());
+    expect(log, contains('web_resource_error'));
+    expect(log, contains('"status":-2'));
+    expect(log, isNot(contains('PRIVATE_NETWORK_DETAIL')));
+  });
+
   test('graduate logout function automatically opens timetable without an exit anchor', () async {
     await session.openTimetable(term: SchoolTerm(73));
     platform.web.javascript = (script) async =>
diff --git a/mobile/test/school/undergraduate_exam_batch_test.dart b/mobile/test/school/undergraduate_exam_batch_test.dart
index 49fc0ac..c0caa42 100644
--- a/mobile/test/school/undergraduate_exam_batch_test.dart
+++ b/mobile/test/school/undergraduate_exam_batch_test.dart
@@ -82,6 +82,10 @@ void main() {
       await finish();
       expect(session.pendingExams!.records, hasLength(12));
       expect(session.pendingExams!.requestedExamTypes, {1, 2, 3});
+      final completedGeneration = session.pageGeneration;
+      platform.delegate.started('https://eams.uestc.edu.cn/eams/');
+      expect(session.pendingExams, isNull);
+      expect(session.pageGeneration, greaterThan(completedGeneration));
     },
   );
   test('last type failure never publishes partial results', () async {
diff --git a/mobile/test/school/undergraduate_timetable_adapter_test.dart b/mobile/test/school/undergraduate_timetable_adapter_test.dart
index 7055593..7cc468b 100644
--- a/mobile/test/school/undergraduate_timetable_adapter_test.dart
+++ b/mobile/test/school/undergraduate_timetable_adapter_test.dart
@@ -9,6 +9,21 @@ import 'package:hepan_everyday/data/schedule_file_import.dart';
 import 'package:hepan_everyday/domain/school_identity.dart';
 
 void main() {
+  test('unrecognized activity writes and incomplete declarations reject the entire timetable', () {
+    const valid =
+        'activity = new TaskActivity("T", "教师", "C", "课程(C.01)", "R", "教室", "010"); '
+        'index = 0*unitCount+0; table0.activities[index][table0.activities[index].length]=activity;';
+    for (final extra in [
+      'table0.activities[11][table0.activities[11].length]=activity;',
+      'activity = new TaskActivity("T", "教师", "C", "另一课程(C.02)", "R", "教室", "010")\n'
+          'index = 0*unitCount+1; table0.activities[index][table0.activities[index].length]=activity;',
+    ]) {
+      expect(
+        () => parseActivityData('$valid $extra', unitCount: 12),
+        throwsFormatException,
+      );
+    }
+  });
   final uri = Uri.parse(
     'https://eams.uestc.edu.cn/eams/courseTableForStd.action',
   );
diff --git a/mobile/test/services/diagnostic_log_test.dart b/mobile/test/services/diagnostic_log_test.dart
new file mode 100644
index 0000000..b0c9218
--- /dev/null
+++ b/mobile/test/services/diagnostic_log_test.dart
@@ -0,0 +1,53 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:hepan_everyday/services/diagnostic_log.dart';
+
+void main() {
+  test(
+    'logs retain only ten minutes across reopening and omit login secrets',
+    () async {
+      final directory = await Directory.systemTemp.createTemp('tp-log-test');
+      addTearDown(() => directory.delete(recursive: true));
+      var now = DateTime.utc(2026, 10, 15, 10);
+      final log = DiagnosticLog(clock: () => now);
+      addTearDown(log.dispose);
+      await log.attach(directory);
+      log.add('old_event');
+      now = now.add(const Duration(minutes: 11));
+      log.navigation(
+        'graduate',
+        'finished',
+        'https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/73?ticket=SECRET&username=PERSON',
+      );
+      log.add(
+        'read_failed',
+        fields: {'code': 'no_timetable', 'password': 'SECRET'},
+      );
+      await log.flush();
+      final restored = DiagnosticLog(clock: () => now);
+      addTearDown(restored.dispose);
+      await restored.attach(directory);
+      final text = utf8.decode(await restored.export());
+      expect(text, contains('navigation_finished'));
+      expect(text, contains('timetable'));
+      expect(text, contains('no_timetable'));
+      for (final value in [
+        'old_event',
+        'SECRET',
+        'PERSON',
+        'ticket',
+        '"password"',
+        'https://',
+      ]) {
+        expect(text, isNot(contains(value)));
+      }
+      now = now.add(const Duration(minutes: 11));
+      expect(
+        utf8.decode(await restored.export()),
+        isNot(contains('no_timetable')),
+      );
+    },
+  );
+}
diff --git a/mobile/test/widgets/exam_query_spacing_test.dart b/mobile/test/widgets/exam_query_spacing_test.dart
new file mode 100644
index 0000000..e0d2630
--- /dev/null
+++ b/mobile/test/widgets/exam_query_spacing_test.dart
@@ -0,0 +1,43 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:hepan_everyday/app/app_controller.dart';
+import 'package:hepan_everyday/app/app_theme.dart';
+import 'package:hepan_everyday/domain/app_snapshot.dart';
+import 'package:hepan_everyday/domain/exam_schedule.dart';
+import 'package:hepan_everyday/domain/school_identity.dart';
+import 'package:hepan_everyday/features/exams/exams_page.dart';
+
+import '../support/fakes.dart';
+
+void main() {
+  testWidgets('query description has breathing room above exam cards', (
+    tester,
+  ) async {
+    final controller = AppController(
+      MemoryStore(),
+      FakeNotifications(),
+      FakeCalendar(),
+      DateTime.now,
+    );
+    addTearDown(controller.dispose);
+    controller.snapshot = AppSnapshot(
+      examSchedule: ExamSchedule(
+        semesterLabel: '2025-2026第二学期',
+        termId: '503',
+        school: SupportedSchool.uestcUndergraduate,
+        requestedExamTypes: {1},
+        records: [const ExamRecord(code: 'C1', name: '测试考试', examTypeId: 1)],
+      ),
+    );
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: ExamsPage(controller: controller, onSync: () {}),
+        ),
+      ),
+    );
+    final description = tester.getRect(find.text('查询类型：期末考试'));
+    final card = tester.getRect(find.byType(SurfaceCard).first);
+    expect(card.top - description.bottom, greaterThanOrEqualTo(12));
+  });
+}
diff --git a/server/feedback/README.md b/server/feedback/README.md
index 420f77f..e570c53 100644
--- a/server/feedback/README.md
+++ b/server/feedback/README.md
@@ -16,6 +16,11 @@ Prepared for Ubuntu + 1Panel on `43.138.57.216`. Public endpoint: `https://app.g
 | `contact` | Optional, max 200 characters | Required, nonblank, max 200 characters |
 | `school` | Must be omitted | Required, nonblank, max 200 characters |
 | `attachments` | Optional, max 3 files, 8 MiB each, 20 MiB aggregate | Must be omitted |
+| `diagnostics` | Optional single UTF-8 text file, max 256 KiB, independent of media count; starts with `TPSchedule diagnostic log` followed by a newline | Must be omitted |
+
+The app defaults diagnostics to off. When selected it snapshots the preceding ten minutes of structured app/login/import/reminder events, at most 500 entries. It excludes credentials, cookies, raw URLs, HTML, timetable contents and feedback text. The server attaches this file as `TPSchedule-diagnostics.txt`; retries must use the identical snapshot and submission ID. The server hashes it with the other attachments for idempotency, and does not log its contents.
+
+To enable this field on an existing deployment, replace the service source and rebuild the same Compose service, keeping `.env`, the idempotency secret and database volume. Existing clients without diagnostics remain compatible. Do not alter the SafeLine/OpenResty routing for this update. See [日志附件更新说明](diagnostic-log-update.md).
 
 Accepted MIME types: `image/jpeg`, `image/png`, `image/gif`, `image/webp`, `image/heic`, `image/heif`, `video/mp4`, `video/quicktime`, `video/x-m4v`, `video/webm`. Send an explicit matching MIME type; `application/octet-stream` is rejected. Container signatures must match. MOV/MP4/M4V/HEIC require an initial valid `ftyp` box with a recognized compatible brand; legacy MOV without `ftyp` is rejected. Checks identify file formats; they do not certify an attachment is harmless or a complete playable file.
 
diff --git a/server/feedback/diagnostic-log-update.md b/server/feedback/diagnostic-log-update.md
new file mode 100644
index 0000000..8b65806
--- /dev/null
+++ b/server/feedback/diagnostic-log-update.md
@@ -0,0 +1,15 @@
+# 可选诊断日志附件更新
+
+APP 的「反馈问题和建议」新增默认关闭的「附带近10分钟诊断日志」。勾选后，反馈邮件多一个 `TPSchedule-diagnostics.txt`，不占用3个图片/视频名额。加入开发的申请不发送日志。
+
+日志包含认证入口打开、页面开始/结束跳转、识别登录状态、请求读取课表/考试、解析成功/失败类别、保存及提醒调度状态。页面地址只保留「身份认证、研究生首页、课表、考试」等类别，不保存完整URL及查询参数。不记录密码、验证码、Cookie、HTML、课程/师生姓名、反馈正文。日志有UTC时间，仅保留运行期间最近10分钟、最多500条；运行时每分钟裁剪，重启时丢弃过期记录。重试使用首次提交时冻结的附件。
+
+## 现有 Ubuntu + 1Panel + 雷池部署
+
+1. 在1Panel找到原反馈服务的目录，例如 `/opt/app-feedback`。保留原 `.env`、Compose项目名和数据库数据卷，不重建SMTP密码及 `IDEMPOTENCY_SECRET`。
+2. 用本版本的 `feedback_service.py` 覆盖同名文件；同时保留本工程的 `main.py`、依赖及Docker构建文件。若统一上传整个部署目录，排除 `.deps`、测试缓存、本机文件及 `.env`，不要覆盖服务器原配置。
+3. 在该目录运行 `docker compose up -d --build feedback`，或在1Panel中重建同一Compose服务。等待健康检查通过。不要执行删除数据卷的操作。
+4. 雷池80/443 → OpenResty10080 → `127.0.0.1:18080` 的原转发关系保持；原 `client_max_body_size 21m` 上限足以容纳20 MiB媒体和256 KiB日志，不需更换域名或端口。
+5. 安装新APP，尝试登录并复现问题，再进入反馈页写问题、勾选日志、提交。到 `tps-david@glowtps.cn` 核对文本附件及时间；该步骤才会真实发送邮件。
+
+若服务器仍为旧版，勾选日志可能被拒绝，APP不会显示发送成功，填写内容保留。不勾选日志的旧协议继续可用。本次仅准备与测试部署代码，未连接服务器或实发SMTP邮件。
diff --git a/server/feedback/feedback_service.py b/server/feedback/feedback_service.py
index 8e4cc35..77cdb4b 100644
--- a/server/feedback/feedback_service.py
+++ b/server/feedback/feedback_service.py
@@ -29,7 +29,8 @@ from starlette.concurrency import run_in_threadpool
 MIB = 1024 * 1024
 FILE_LIMIT = 8 * MIB
 TOTAL_FILE_LIMIT = 20 * MIB
-BODY_LIMIT = TOTAL_FILE_LIMIT + 64 * 1024
+LOG_LIMIT = 256 * 1024
+BODY_LIMIT = TOTAL_FILE_LIMIT + LOG_LIMIT + 64 * 1024
 ID_PATTERN = re.compile(r"[A-Za-z0-9_-]{16,128}\Z")
 ADDRESS_PATTERN = re.compile(r"[A-Za-z0-9._%+-]+@(?:[A-Za-z0-9-]+\.)+[A-Za-z]{2,63}\Z")
 
@@ -362,10 +363,15 @@ def safe_filename(filename, extension):
 
 async def parse_submission(request):
     try:
-        async with request.form(max_files=3, max_fields=5, max_part_size=20000) as form:
-            fields, uploads = {}, []
+        async with request.form(max_files=4, max_fields=5, max_part_size=20000) as form:
+            fields, uploads, diagnostic_upload = {}, [], None
             for name, value in form.multi_items():
                 if isinstance(value, UploadFile):
+                    if name == "diagnostics":
+                        if diagnostic_upload is not None:
+                            raise ApiError(422, "validation_error", "Only one diagnostic log is allowed.")
+                        diagnostic_upload = value
+                        continue
                     if name != "attachments":
                         raise ApiError(422, "validation_error", "Unexpected file field.")
                     uploads.append(value)
@@ -387,10 +393,12 @@ async def parse_submission(request):
             if kind == "problem":
                 if not fields.get("message", "").strip() or "school" in fields:
                     raise ApiError(422, "validation_error", "Problem feedback requires message and must omit school.")
-            elif ("message" in fields or uploads or not fields.get("school", "").strip()
+            elif ("message" in fields or uploads or diagnostic_upload or not fields.get("school", "").strip()
                   or not fields.get("contact", "").strip()):
                 raise ApiError(422, "validation_error", "Development requests require school and contact; omit message and attachments.")
             attachments, total = [], 0
+            if len(uploads) > 3:
+                raise ApiError(413, "upload_too_large", "Maximum three media files.")
             for upload in uploads:
                 data = await upload.read(FILE_LIMIT + 1)
                 total += len(data)
@@ -401,6 +409,17 @@ async def parse_submission(request):
                 if not valid:
                     raise ApiError(415, "unsupported_media", "Attachment MIME type and file signature must match a supported image or video.")
                 attachments.append((safe_filename(upload.filename, extension), mime, data))
+            if diagnostic_upload is not None:
+                data = await diagnostic_upload.read(LOG_LIMIT + 1)
+                if len(data) > LOG_LIMIT:
+                    raise ApiError(413, "upload_too_large", "Diagnostic log exceeds 256 KiB.")
+                try:
+                    text = data.decode("utf-8")
+                except UnicodeDecodeError:
+                    raise ApiError(415, "unsupported_media", "Diagnostic log must be UTF-8 text.") from None
+                if (diagnostic_upload.content_type or '').split(';')[0].strip().lower() != 'text/plain' or '\x00' in text or not text.startswith('TPSchedule diagnostic log\n'):
+                    raise ApiError(415, "unsupported_media", "Invalid diagnostic log.")
+                attachments.append(('TPSchedule-diagnostics.txt', 'text/plain', data))
             return fields, attachments
     except HTTPException as exc:
         detail = str(exc.detail).lower()
diff --git a/server/feedback/tests/test_feedback.py b/server/feedback/tests/test_feedback.py
index 18ebd23..e42fbd7 100644
--- a/server/feedback/tests/test_feedback.py
+++ b/server/feedback/tests/test_feedback.py
@@ -62,6 +62,40 @@ def test_success_only_after_sender_accepted_and_retry_is_durable(service):
     assert len(sender.messages) == 1
 
 
+def test_diagnostic_log_is_extra_email_attachment_and_retry_stays_idempotent(service):
+    client, sender, _ = service
+    log = b'TPSchedule diagnostic log\n{"event":"login_opened"}\n'
+    files = [("submission_id", (None, ID)), ("type", (None, "problem")),
+             ("message", (None, "Login stopped"))] + [
+             ("attachments", (f"image-{i}.png", PNG, "image/png")) for i in range(3)] + [
+             ("diagnostics", ("TPSchedule-diagnostics.txt", log, "text/plain; charset=utf-8"))]
+    assert client.post('/v1/feedback', files=files).status_code == 200
+    attachments = list(sender.messages[0].iter_attachments())
+    assert len(attachments) == 4
+    assert attachments[-1].get_filename() == 'TPSchedule-diagnostics.txt'
+    assert attachments[-1].get_payload(decode=True) == log
+    assert client.post('/v1/feedback', files=files).status_code == 200
+    assert len(sender.messages) == 1
+
+
+@pytest.mark.parametrize('name,kind,data,mime,status', [
+    ('diagnostics', 'problem', b'not a log', 'text/plain', 415),
+    ('diagnostics', 'problem', b'TPSchedule diagnostic log\n\xff', 'text/plain', 415),
+    ('diagnostics', 'problem', b'TPSchedule diagnostic log\n' + b'x' * (256 * 1024), 'text/plain', 413),
+    ('diagnostics', 'development', b'TPSchedule diagnostic log\n', 'text/plain', 422),
+], ids=['header', 'utf8', 'oversize', 'development'])
+def test_invalid_diagnostics_never_send(service, name, kind, data, mime, status):
+    client, sender, _ = service
+    fields = [('submission_id', (None, ID)), ('type', (None, kind))]
+    if kind == 'problem':
+        fields += [('message', (None, 'Cannot import'))]
+    else:
+        fields += [('school', (None, 'University')), ('contact', (None, 'QQ123'))]
+    response = client.post('/v1/feedback', files=fields + [(name, ('log.txt', data, mime))])
+    assert response.status_code == status
+    assert not sender.messages
+
+
 def test_reusing_id_with_other_content_rejected(service):
     client, sender, _ = service
     assert post(client).status_code == 200