v1.2.0

默认 Redis 缓存 3 分钟、本地缓存 30 秒，可通过环境变量调整。
缓存键包含数据权限范围、有效学院和全部筛选条件，避免跨学院串数据。
Excel 导出保持实时查询，不使用摘要缓存。
无需数据库迁移。

.env.example

@@ -6,6 +6,18 @@ Database__Provider=MySql
 Database__ApplyMigrationsOnStartup=false
 Database__CommandTimeoutSeconds=30
 ConnectionStrings__MySql="Server=db.example.edu.cn;Port=3306;Database=jiaowu;User=APP_USER;Password=REPLACE_WITH_A_STRONG_PASSWORD;SslMode=VerifyFull;SslCa=/etc/jiaowu/mysql-ca.pem;"
+# Redis 是可选加速器；留空时应用仅使用进程内缓存。
+# ConnectionStrings__Redis="redis.example.edu.cn:6380,user=jiaowu,password=REPLACE_WITH_A_STRONG_PASSWORD,ssl=true,abortConnect=false"
+
+Cache__Enabled=true
+Cache__KeyPrefix=jiaowu:v1
+Cache__ReferenceExpirationMinutes=30
+Cache__ReferenceLocalExpirationSeconds=120
+Cache__TimetableExpirationMinutes=10
+Cache__TimetableLocalExpirationSeconds=30
+Cache__AnalyticsExpirationMinutes=3
+Cache__AnalyticsLocalExpirationSeconds=30
+Cache__MaximumPayloadKilobytes=2048
 
 Jwt__Issuer=Jiaowu.Api
 Jwt__Audience=Jiaowu.Web

.gitignore

@@ -17,3 +17,4 @@ src/Jiaowu.Api/wwwroot/
 !.env.example
 !.env.docker.example
 certs/
+publish/

README.md

@@ -219,6 +219,35 @@ SQLite 只用于本地开发：新库通过 `EnsureCreated` 建立，已有开
 
 - `/health/live`：只检查进程存活。
 - `/health`、`/health/ready`：实际检查数据库连接，失败时返回 HTTP 503。
+- `/health/cache`：检查可选 Redis；未配置 Redis 时返回 `disabled`，Redis
+  故障不会影响数据库就绪探针。
+
+### 查询缓存与 Redis
+
+应用使用 HybridCache 统一管理进程内一级缓存和可选 Redis 二级缓存。目前缓存范围为
+学生激活/基础数据选项、匿名可访问的已发布课表、仪表盘以及统计分析摘要。统计缓存键
+包含有效数据范围、学院和规范化筛选条件，避免跨学院复用；统计 Excel 导出仍实时查询。
+选课容量、成绩写入、考勤、审批、通知未读数、权限和后台任务状态仍直接以 MySQL 为准。
+
+不配置 `ConnectionStrings__Redis` 时，开发和单机部署仍使用进程内缓存，不要求安装
+Redis。生产环境使用 Redis 时，通过环境变量配置连接串，例如：
+
+```text
+ConnectionStrings__Redis=redis.internal:6380,user=jiaowu,password=REPLACE_ME,ssl=true,abortConnect=false
+```
+
+仪表盘和统计摘要默认在 Redis 中缓存 3 分钟、进程内缓存 30 秒，可分别通过
+`Cache__AnalyticsExpirationMinutes` 和 `Cache__AnalyticsLocalExpirationSeconds`
+调整。该类汇总采用短 TTL 控制数据新鲜度，不要求每个业务写入点同步清理缓存。
+
+Redis 只作为可丢弃的查询缓存。连接失败时应用回源数据库，普通启动和
+`/health/ready` 不依赖 Redis；可以单独检查 `/health/cache`。缓存键自动包含运行环境，
+同一 Redis 可以安全承载 Development、Staging 和 Production，但生产环境仍建议使用
+独立实例、私有网络、ACL 和 TLS。
+
+`compose.example.yml` 包含不暴露宿主机端口的 Redis 服务，限制为 256 MB 并使用
+`allkeys-lfu` 淘汰策略，不启用持久化。`compose.app.example.yml` 不创建 Redis；
+如需连接外部 Redis，在 `.env` 中配置上述连接串即可。
 
 ## 跨平台发布与 Docker
 

compose.example.yml

@@ -13,6 +13,9 @@ x-jiaowu-environment: &jiaowu-environment
   Database__ApplyMigrationsOnStartup: "false"
   Database__CommandTimeoutSeconds: "30"
   ConnectionStrings__MySql: "Server=mysql;Port=3306;Database=${MYSQL_DATABASE:-jiaowu_demo};User=${MYSQL_USER:-jiaowu};Password=${MYSQL_PASSWORD:?请在 .env.docker 中设置 MYSQL_PASSWORD};SslMode=Disabled;"
+  ConnectionStrings__Redis: "redis:6379,abortConnect=false"
+  Cache__Enabled: "true"
+  Cache__KeyPrefix: "jiaowu:v1"
   Jwt__Issuer: Jiaowu.Api
   Jwt__Audience: Jiaowu.Web
   Jwt__Key: "${JWT_KEY:?请在 .env.docker 中设置 JWT_KEY}"
@@ -30,6 +33,29 @@ x-json-logging: &json-logging
     max-file: "3"
 
 services:
+  redis:
+    image: redis:8.8-alpine
+    restart: unless-stopped
+    command:
+      - redis-server
+      - --save
+      - ""
+      - --appendonly
+      - "no"
+      - --maxmemory
+      - 256mb
+      - --maxmemory-policy
+      - allkeys-lfu
+    healthcheck:
+      test:
+        - CMD
+        - redis-cli
+        - ping
+      interval: 5s
+      timeout: 3s
+      retries: 10
+    logging: *json-logging
+
   mysql:
     image: mysql:8.4
     restart: unless-stopped
@@ -69,6 +95,8 @@ services:
     <<: *jiaowu-image
     environment: *jiaowu-environment
     depends_on:
+      redis:
+        condition: service_started
       mysql:
         condition: service_healthy
       migrate:

src/Jiaowu.Api/Controllers/ApprovalsController.cs

@@ -80,6 +80,9 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     {
         var studentId = await GetStudentIdAsync(ct);
         if (studentId is null) return StudentNotFound();
+        if (!await IsStudentCourseAvailableForApplicationAsync(
+                studentId.Value, req.TeachingTaskId, ct))
+            return ConflictProblem("该课程不在您当前或已发布课表的修读课程中，请刷新课程列表后重试。");
         if (await db.CourseExemptions.AnyAsync(x => x.StudentId == studentId && x.TeachingTaskId == req.TeachingTaskId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有免修申请在审核中。");
         var ex = new CourseExemption { StudentId = studentId.Value, TeachingTaskId = req.TeachingTaskId, Reason = req.Reason.Trim() };
@@ -141,6 +144,9 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
+        if (!await IsStudentCourseAvailableForApplicationAsync(
+                sid.Value, req.TeachingTaskId, ct))
+            return ConflictProblem("该课程不在您当前或已发布课表的修读课程中，请刷新课程列表后重试。");
         if (await db.DeferredExams.AnyAsync(x => x.StudentId == sid && x.TeachingTaskId == req.TeachingTaskId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有缓考申请在审核中。");
         var d = new DeferredExam { StudentId = sid.Value, TeachingTaskId = req.TeachingTaskId, Reason = req.Reason.Trim() };
@@ -248,12 +254,75 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     }
 
     // ═══════════════ Course Substitution ═══════════════
+    [HttpGet("substitutions/mine")]
+    [Authorize(Roles = SystemRoles.Student)]
+    public async Task<ActionResult> GetMySubstitutions(CancellationToken ct)
+    {
+        var sid = await GetStudentIdAsync(ct);
+        if (sid is null) return StudentNotFound();
+        return Ok(await db.CourseSubstitutions.AsNoTracking()
+            .Where(x => x.StudentId == sid)
+            .OrderByDescending(x => x.CreatedAt)
+            .Select(x => new StudentCourseSubstitutionRecord(
+                x.Id,
+                x.Status,
+                x.Reason,
+                x.ReviewComment,
+                x.SubmittedAt,
+                x.OriginalCourse!.Code,
+                x.OriginalCourse.Name,
+                x.SubstituteCourse!.Code,
+                x.SubstituteCourse.Name))
+            .ToListAsync(ct));
+    }
+
     [HttpPost("substitutions")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> ApplySubstitution(SubstitutionRequest req, CancellationToken ct)
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
+        if (req.OriginalCourseId == req.SubstituteCourseId)
+            return ConflictProblem("被替代课程和替代课程不能相同。");
+        var isAssignedCourse = await db.TeachingTasks.AsNoTracking()
+            .AnyAsync(task =>
+                task.CourseId == req.OriginalCourseId &&
+                task.Status == TeachingTaskStatus.Published &&
+                !task.AcademicTerm!.IsArchived &&
+                (task.AcademicTerm.IsCurrent ||
+                 db.ScheduleEntries.Any(entry =>
+                     entry.TeachingTaskId == task.Id &&
+                     entry.SchedulePlan!.Status ==
+                         SchedulePlanStatus.Published)) &&
+                (task.Classes.Any(item =>
+                     item.AdministrativeClass!.Students.Any(student =>
+                         student.Id == sid.Value)) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == sid.Value &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                         task.Id)),
+                ct);
+        var hasFailedOriginal = await db.GradeRecords.AsNoTracking()
+            .AnyAsync(record =>
+                record.StudentId == sid.Value &&
+                record.GradeSheet!.Status == GradeSheetStatus.Published &&
+                record.GradeSheet.TeachingTask!.CourseId ==
+                    req.OriginalCourseId &&
+                record.TotalScore < 60,
+                ct);
+        var canReplaceOriginal = isAssignedCourse || hasFailedOriginal;
+        if (!canReplaceOriginal)
+            return ConflictProblem("被替代课程必须是当前或已发布课表的修读课程，或已有未通过成绩的课程。");
+        var hasPassedSubstitute = await db.GradeRecords.AsNoTracking()
+            .AnyAsync(x =>
+                x.StudentId == sid.Value &&
+                x.GradeSheet!.Status == GradeSheetStatus.Published &&
+                x.GradeSheet.TeachingTask!.CourseId == req.SubstituteCourseId &&
+                x.TotalScore >= 60,
+                ct);
+        if (!hasPassedSubstitute)
+            return ConflictProblem("替代课程必须具有已发布且及格的成绩。");
         if (await db.CourseSubstitutions.AnyAsync(x => x.StudentId == sid && x.OriginalCourseId == req.OriginalCourseId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有替代申请在审核中。");
         var cs = new CourseSubstitution { StudentId = sid.Value, OriginalCourseId = req.OriginalCourseId, SubstituteCourseId = req.SubstituteCourseId, Reason = req.Reason.Trim() };
@@ -319,16 +388,50 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         return NoContent();
     }
 
-    // ═══════════════ Student enrolled courses ═══════════════
+    // ═══════════════ Student course options ═══════════════
     [HttpGet("my-courses")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> GetMyEnrolledCourses(CancellationToken ct)
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
-        var courses = await db.CourseEnrollments.AsNoTracking()
-            .Where(x => x.StudentId == sid && x.Status == CourseEnrollmentStatus.Enrolled)
-            .Select(x => new { x.CourseSelectionOffering!.TeachingTaskId, x.CourseSelectionOffering.TeachingTask!.TaskNumber, CourseCode = x.CourseSelectionOffering.TeachingTask.Course!.Code, CourseName = x.CourseSelectionOffering.TeachingTask.Course.Name })
+        var courses = await db.TeachingTasks.AsNoTracking()
+            .Where(task =>
+                task.Status == TeachingTaskStatus.Published &&
+                !task.AcademicTerm!.IsArchived &&
+                (task.AcademicTerm.IsCurrent ||
+                 db.ScheduleEntries.Any(entry =>
+                     entry.TeachingTaskId == task.Id &&
+                     entry.SchedulePlan!.Status ==
+                         SchedulePlanStatus.Published)) &&
+                (task.Classes.Any(item =>
+                     item.AdministrativeClass!.Students.Any(student =>
+                         student.Id == sid.Value)) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == sid.Value &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                         task.Id)))
+            .OrderByDescending(x => x.AcademicTerm!.IsCurrent)
+            .ThenByDescending(x => x.AcademicTerm!.StartDate)
+            .ThenBy(x => x.Course!.Code)
+            .ThenBy(x => x.TaskNumber)
+            .Select(x => new StudentApprovalCourseOption(
+                x.Id,
+                x.CourseId,
+                x.TaskNumber,
+                x.Course!.Code,
+                x.Course.Name,
+                x.Course.Credits,
+                x.AcademicTerm!.Name,
+                x.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .ThenBy(item => item.Teacher!.Name)
+                    .Select(item => item.Teacher!.Name),
+                db.ScheduleEntries.Any(entry =>
+                    entry.TeachingTaskId == x.Id &&
+                    entry.SchedulePlan!.Status == SchedulePlanStatus.Published),
+                x.SchedulingMode))
             .ToListAsync(ct);
         return Ok(courses);
     }
@@ -341,8 +444,18 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         if (sid is null) return StudentNotFound();
         var grades = await db.GradeRecords.AsNoTracking()
             .Where(x => x.StudentId == sid && x.GradeSheet!.Status == GradeSheetStatus.Published)
-            .Select(x => new { CourseId = x.GradeSheet!.TeachingTask!.CourseId, CourseCode = x.GradeSheet.TeachingTask.Course!.Code, CourseName = x.GradeSheet.TeachingTask.Course.Name, x.TotalScore, x.GradePoint, x.ExamStatus })
-            .OrderBy(x => x.CourseCode)
+            .OrderByDescending(x => x.GradeSheet!.PublishedAt)
+            .Select(x => new StudentApprovalGradeOption(
+                x.GradeSheet!.TeachingTask!.CourseId,
+                x.GradeSheet.TeachingTask.Course!.Code,
+                x.GradeSheet.TeachingTask.Course.Name,
+                x.GradeSheet.TeachingTask.Course.Credits,
+                x.TotalScore,
+                x.GradePoint,
+                x.ExamStatus,
+                x.GradeSheet.TeachingTask.AcademicTerm!.Name,
+                x.GradeSheet.TeachingTask.TaskNumber,
+                x.GradeSheet.PublishedAt))
             .ToListAsync(ct);
         return Ok(grades);
     }
@@ -377,6 +490,27 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     }
 
     private async Task<Guid?> GetStudentIdAsync(CancellationToken ct) => await db.Students.Where(s => s.UserId == scope.Current.UserId).Select(s => (Guid?)s.Id).FirstOrDefaultAsync(ct);
+    private async Task<bool> IsStudentCourseAvailableForApplicationAsync(
+        Guid studentId,
+        Guid teachingTaskId,
+        CancellationToken ct) =>
+        await db.TeachingTasks.AsNoTracking().AnyAsync(task =>
+            task.Id == teachingTaskId &&
+            task.Status == TeachingTaskStatus.Published &&
+            !task.AcademicTerm!.IsArchived &&
+            (task.AcademicTerm.IsCurrent ||
+             db.ScheduleEntries.Any(entry =>
+                 entry.TeachingTaskId == task.Id &&
+                 entry.SchedulePlan!.Status == SchedulePlanStatus.Published)) &&
+            (task.Classes.Any(item =>
+                 item.AdministrativeClass!.Students.Any(student =>
+                     student.Id == studentId)) ||
+             db.CourseEnrollments.Any(enrollment =>
+                 enrollment.StudentId == studentId &&
+                 enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                 enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                     task.Id)),
+            ct);
     private ActionResult StudentNotFound() => Conflict(new ProblemDetails { Title = "未关联学生档案", Detail = "当前账号未关联有效学生档案。", Status = 409 });
 
     private async Task NotifyManagers(string title, string content, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, title, content, cancellationToken: ct); await NotificationService.SendToRoleAsync(db, SystemRoles.AcademicAdmin, title, content, cancellationToken: ct); }
@@ -390,6 +524,38 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
 }
 
 public sealed record ApprovalItem(Guid Id, string Type, string Label, string Title, string Desc, DateTime Time, string College);
+public sealed record StudentApprovalCourseOption(
+    Guid TeachingTaskId,
+    Guid CourseId,
+    string TaskNumber,
+    string CourseCode,
+    string CourseName,
+    decimal Credits,
+    string AcademicTermName,
+    IEnumerable<string> TeacherNames,
+    bool HasPublishedSchedule,
+    TeachingTaskSchedulingMode SchedulingMode);
+public sealed record StudentApprovalGradeOption(
+    Guid CourseId,
+    string CourseCode,
+    string CourseName,
+    decimal Credits,
+    decimal? TotalScore,
+    decimal? GradePoint,
+    GradeExamStatus ExamStatus,
+    string AcademicTermName,
+    string TaskNumber,
+    DateTime? PublishedAt);
+public sealed record StudentCourseSubstitutionRecord(
+    Guid Id,
+    ApprovalStatus Status,
+    string Reason,
+    string? ReviewComment,
+    DateTime SubmittedAt,
+    string OriginalCourseCode,
+    string OriginalCourseName,
+    string SubstituteCourseCode,
+    string SubstituteCourseName);
 public sealed record ExemptionRequest(Guid TeachingTaskId, [Required, MaxLength(500)] string Reason);
 public sealed record GradeModRequest(Guid GradeRecordId, decimal RequestedScore, [Required, MaxLength(500)] string Reason);
 public sealed record SubstitutionRequest(Guid OriginalCourseId, Guid SubstituteCourseId, [Required, MaxLength(500)] string Reason);

src/Jiaowu.Api/Controllers/AuthController.cs

@@ -3,6 +3,7 @@ using System.Security.Claims;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity;
@@ -17,35 +18,51 @@ namespace Jiaowu.Api.Controllers;
 public sealed class AuthController(
     AppDbContext db,
     UserManager<ApplicationUser> userManager,
-    ITokenService tokenService) : ControllerBase
+    ITokenService tokenService,
+    IAppCache cache) : ControllerBase
 {
     [AllowAnonymous]
     [HttpGet("activation-options")]
     public async Task<ActionResult> GetActivationOptions(CancellationToken cancellationToken)
+    {
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.ActivationOptions,
+            async token =>
             {
                 var colleges = await db.Colleges.AsNoTracking()
                     .Where(x => x.IsEnabled)
                     .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name })
-            .ToListAsync(cancellationToken);
+                    .Select(x => new ActivationCollegeOption(x.Id, x.Code, x.Name))
+                    .ToListAsync(token);
                 var majors = await db.Majors.AsNoTracking()
                     .Where(x => x.IsEnabled && x.College!.IsEnabled)
                     .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.CollegeId })
-            .ToListAsync(cancellationToken);
+                    .Select(x => new ActivationMajorOption(
+                        x.Id, x.Code, x.Name, x.CollegeId))
+                    .ToListAsync(token);
                 var classes = await db.AdministrativeClasses.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
+                    .Where(x =>
+                        x.IsEnabled &&
+                        x.Major!.IsEnabled &&
+                        x.Major.College!.IsEnabled)
                     .OrderByDescending(x => x.Grade)
                     .ThenBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.Grade, x.MajorId })
-            .ToListAsync(cancellationToken);
-        return Ok(new
-        {
-            Colleges = colleges,
-            Majors = majors,
-            Classes = classes,
-            Grades = classes.Select(x => x.Grade).Distinct().OrderByDescending(x => x)
-        });
+                    .Select(x => new ActivationClassOption(
+                        x.Id, x.Code, x.Name, x.Grade, x.MajorId))
+                    .ToListAsync(token);
+                return new ActivationOptionsResponse(
+                    colleges,
+                    majors,
+                    classes,
+                    classes.Select(x => x.Grade)
+                        .Distinct()
+                        .OrderByDescending(x => x)
+                        .ToList());
+            },
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
     }
 
     [AllowAnonymous]
@@ -219,3 +236,24 @@ public sealed record CurrentUserResponse(
     IEnumerable<string> Roles,
     Guid? CollegeId,
     string EffectiveDataScope);
+
+public sealed record ActivationOptionsResponse(
+    IReadOnlyList<ActivationCollegeOption> Colleges,
+    IReadOnlyList<ActivationMajorOption> Majors,
+    IReadOnlyList<ActivationClassOption> Classes,
+    IReadOnlyList<int> Grades);
+
+public sealed record ActivationCollegeOption(Guid Id, string Code, string Name);
+
+public sealed record ActivationMajorOption(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId);
+
+public sealed record ActivationClassOption(
+    Guid Id,
+    string Code,
+    string Name,
+    int Grade,
+    Guid MajorId);

src/Jiaowu.Api/Controllers/BaseDataController.cs

@@ -2,6 +2,7 @@ using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Common;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -12,7 +13,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize]
 [Route("api/base-data")]
-public sealed class BaseDataController(AppDbContext db) : ControllerBase
+public sealed class BaseDataController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     private const string Administrators =
         $"{SystemRoles.SuperAdmin},{SystemRoles.AcademicAdmin}";
@@ -20,9 +21,14 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
     [HttpGet("campuses")]
     public async Task<ActionResult<IReadOnlyCollection<Campus>>> GetCampuses(
         CancellationToken cancellationToken) =>
-        await db.Campuses.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("campuses"),
+            token => db.Campuses.AsNoTracking()
                 .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("campuses")]
     [Authorize(Roles = Administrators)]
@@ -52,21 +58,32 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         if (entity is null) return NotFound();
         ApplyCatalog(entity, request);
         entity.Address = request.Description?.Trim();
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("colleges")]
-    public async Task<ActionResult<object>> GetColleges(CancellationToken cancellationToken) =>
-        Ok(await db.Colleges.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
+    public async Task<ActionResult<object>> GetColleges(CancellationToken cancellationToken)
     {
-                x.Id, x.Code, x.Name, x.ShortName, x.CampusId,
-                CampusName = x.Campus != null ? x.Campus.Name : null,
-                x.IsEnabled, x.SortOrder
-            })
-            .ToListAsync(cancellationToken));
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("colleges"),
+            token => db.Colleges.AsNoTracking()
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
+                .Select(x => new CollegeListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.ShortName,
+                    x.CampusId,
+                    x.Campus != null ? x.Campus.Name : null,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpPost("colleges")]
     [Authorize(Roles = Administrators)]
@@ -104,29 +121,46 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         ApplyCatalog(entity, request);
         entity.ShortName = request.ShortName?.Trim();
         entity.CampusId = request.CampusId;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("majors")]
-    public async Task<ActionResult<object>> GetMajors(CancellationToken cancellationToken) =>
-        Ok(await db.Majors.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
+    public async Task<ActionResult<object>> GetMajors(CancellationToken cancellationToken)
     {
-                x.Id, x.Code, x.Name, x.CollegeId,
-                CollegeName = x.College!.Name,
-                x.DegreeType, x.SchoolingYears, x.IsEnabled, x.SortOrder
-            })
-            .ToListAsync(cancellationToken));
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("majors"),
+            token => db.Majors.AsNoTracking()
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
+                .Select(x => new MajorListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.CollegeId,
+                    x.College!.Name,
+                    x.DegreeType,
+                    x.SchoolingYears,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("course-categories")]
     public async Task<ActionResult<IReadOnlyCollection<CourseCategory>>> GetCourseCategories(
         CancellationToken cancellationToken) =>
-        await db.CourseCategories.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("course-categories"),
+            token => db.CourseCategories.AsNoTracking()
                 .OrderBy(x => x.SortOrder)
                 .ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("course-categories")]
     [Authorize(Roles = Administrators)]
@@ -154,7 +188,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         var entity = await db.CourseCategories.FindAsync([id], cancellationToken);
         if (entity is null) return NotFound();
         ApplyCatalog(entity, request);
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -193,23 +227,35 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.CollegeId = request.CollegeId;
         entity.DegreeType = request.DegreeType.Trim();
         entity.SchoolingYears = request.SchoolingYears;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("classes")]
-    public async Task<ActionResult<object>> GetClasses(CancellationToken cancellationToken) =>
-        Ok(await db.AdministrativeClasses.AsNoTracking()
-            .OrderByDescending(x => x.Grade).ThenBy(x => x.Code)
-            .Select(x => new
+    public async Task<ActionResult<object>> GetClasses(CancellationToken cancellationToken)
     {
-                x.Id, x.Code, x.Name, x.MajorId,
-                MajorName = x.Major!.Name,
-                CollegeName = x.Major.College!.Name,
-                x.Grade, x.CounselorUserId, x.CounselorName,
-                x.IsEnabled, x.SortOrder
-            })
-            .ToListAsync(cancellationToken));
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("classes"),
+            token => db.AdministrativeClasses.AsNoTracking()
+                .OrderByDescending(x => x.Grade).ThenBy(x => x.Code)
+                .Select(x => new AdministrativeClassListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.MajorId,
+                    x.Major!.Name,
+                    x.Major.College!.Name,
+                    x.Grade,
+                    x.CounselorUserId,
+                    x.CounselorName,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("counselors")]
     [Authorize(Roles = Administrators)]
@@ -279,18 +325,23 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.Grade = request.Grade;
         entity.CounselorUserId = request.CounselorUserId;
         entity.CounselorName = counselorName;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("terms")]
     public async Task<ActionResult<IReadOnlyCollection<AcademicTerm>>> GetTerms(
         CancellationToken cancellationToken) =>
-        await db.AcademicTerms.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("terms"),
+            token => db.AcademicTerms.AsNoTracking()
                 .OrderByDescending(x => x.IsCurrent)
                 .ThenBy(x => x.IsArchived)
                 .ThenByDescending(x => x.StartDate)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("terms")]
     [Authorize(Roles = Administrators)]
@@ -360,7 +411,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.StartDate = request.StartDate;
         entity.EndDate = request.EndDate;
         entity.IsCurrent = request.IsCurrent;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -384,7 +435,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         foreach (var currentTerm in currentTerms)
             currentTerm.IsCurrent = false;
         entity.IsCurrent = true;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -402,7 +453,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
 
         entity.IsArchived = true;
         entity.ArchivedAt = DateTime.UtcNow;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -418,35 +469,59 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
 
         entity.IsArchived = false;
         entity.ArchivedAt = null;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("classrooms")]
-    public async Task<ActionResult<object>> GetClassrooms(CancellationToken cancellationToken) =>
-        Ok(await db.Classrooms.AsNoTracking()
+    public async Task<ActionResult<object>> GetClassrooms(CancellationToken cancellationToken)
+    {
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("classrooms"),
+            token => db.Classrooms.AsNoTracking()
                 .OrderBy(x => x.Building!.Campus!.SortOrder)
                 .ThenBy(x => x.Code)
-            .Select(x => new
-            {
-                x.Id, x.Code, x.Name, x.BuildingId,
-                CampusId = x.Building!.CampusId,
-                BuildingName = x.Building!.Name,
-                CampusName = x.Building.Campus!.Name,
-                x.Capacity, x.RoomType, x.Equipment, x.IsEnabled, x.SortOrder
-            })
-            .ToListAsync(cancellationToken));
+                .Select(x => new ClassroomListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.BuildingId,
+                    x.Building!.CampusId,
+                    x.Building.Name,
+                    x.Building.Campus!.Name,
+                    x.Capacity,
+                    x.RoomType,
+                    x.Equipment,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("buildings")]
-    public async Task<ActionResult<object>> GetBuildings(CancellationToken cancellationToken) =>
-        Ok(await db.Buildings.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
+    public async Task<ActionResult<object>> GetBuildings(CancellationToken cancellationToken)
     {
-                x.Id, x.Code, x.Name, x.CampusId,
-                CampusName = x.Campus!.Name, x.IsEnabled, x.SortOrder
-            })
-            .ToListAsync(cancellationToken));
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("buildings"),
+            token => db.Buildings.AsNoTracking()
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
+                .Select(x => new BuildingListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.CampusId,
+                    x.Campus!.Name,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpPost("buildings")]
     [Authorize(Roles = Administrators)]
@@ -503,7 +578,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.Capacity = request.Capacity;
         entity.RoomType = request.RoomType.Trim();
         entity.Equipment = request.Equipment?.Trim();
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -533,7 +608,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         db.Remove(entity);
         try
         {
-            await db.SaveChangesAsync(cancellationToken);
+            await SaveAndInvalidateAsync(cancellationToken);
             return NoContent();
         }
         catch (DbUpdateException)
@@ -556,7 +631,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         db.Add(entity);
         try
         {
-            await db.SaveChangesAsync(cancellationToken);
+            await SaveAndInvalidateAsync(cancellationToken);
         }
         catch (DbUpdateException)
         {
@@ -566,6 +641,12 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         return CreatedAtAction(action, new { id = entity.Id }, entity);
     }
 
+    private async Task SaveAndInvalidateAsync(CancellationToken cancellationToken)
+    {
+        await db.SaveChangesAsync(cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.BaseData, cancellationToken);
+    }
+
     private async Task<string?> GetCounselorNameAsync(
         Guid? userId,
         CancellationToken cancellationToken)
@@ -649,3 +730,60 @@ public sealed record ClassroomRequest(
     [Required, MaxLength(40)] string RoomType,
     [MaxLength(300)] string? Equipment)
     : CatalogRequest(Code, Name, SortOrder, IsEnabled);
+
+public sealed record CollegeListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    string? ShortName,
+    Guid? CampusId,
+    string? CampusName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record MajorListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId,
+    string CollegeName,
+    string DegreeType,
+    int SchoolingYears,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record AdministrativeClassListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid MajorId,
+    string MajorName,
+    string CollegeName,
+    int Grade,
+    Guid? CounselorUserId,
+    string? CounselorName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record BuildingListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CampusId,
+    string CampusName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record ClassroomListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid BuildingId,
+    Guid CampusId,
+    string BuildingName,
+    string CampusName,
+    int Capacity,
+    string RoomType,
+    string? Equipment,
+    bool IsEnabled,
+    int SortOrder);

src/Jiaowu.Api/Controllers/BaseDataExcelController.cs

@@ -1,6 +1,7 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Common;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -12,7 +13,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize(Roles = Administrators)]
 [Route("api/base-data")]
-public sealed class BaseDataExcelController(AppDbContext db) : ControllerBase
+public sealed class BaseDataExcelController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     private const string Administrators =
         $"{SystemRoles.SuperAdmin},{SystemRoles.AcademicAdmin}";
@@ -114,6 +115,9 @@ public sealed class BaseDataExcelController(AppDbContext db) : ControllerBase
 
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.BaseData,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/CoursesController.cs

@@ -3,6 +3,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -15,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/courses")]
 public sealed class CoursesController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string WriteRoles =
         SystemRoles.SuperAdmin + "," +
@@ -273,6 +275,7 @@ public sealed class CoursesController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return created ? Created(string.Empty, new { id }) : NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/CoursesExcelController.cs

@@ -2,6 +2,7 @@ using System.Globalization;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -15,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/courses")]
 public sealed class CoursesExcelController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string WriteRoles =
         SystemRoles.SuperAdmin + "," +
@@ -141,6 +143,9 @@ public sealed class CoursesExcelController(
 
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.Timetables,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/DashboardController.cs

@@ -1,18 +1,35 @@
+using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
 
 namespace Jiaowu.Api.Controllers;
 
 [ApiController]
 [Authorize]
 [Route("api/dashboard")]
-public sealed class DashboardController(AppDbContext db) : ControllerBase
+public sealed class DashboardController(
+    AppDbContext db,
+    IAppCache appCache,
+    IOptions<JsonOptions> jsonOptions) : ControllerBase
 {
     [HttpGet]
     public async Task<ActionResult<object>> Get(CancellationToken cancellationToken)
+    {
+        var response = await appCache.GetOrCreateAsync(
+            AppCacheKeys.Dashboard,
+            LoadAsync,
+            AppCacheProfile.Analytics,
+            [AppCacheTags.Analytics],
+            cancellationToken);
+        return response;
+    }
+
+    private async Task<JsonElement> LoadAsync(CancellationToken cancellationToken)
     {
         var currentTerm = await db.AcademicTerms
             .AsNoTracking()
@@ -20,7 +37,8 @@ public sealed class DashboardController(AppDbContext db) : ControllerBase
             .Select(x => new { x.Id, x.Name, x.StartDate, x.EndDate })
             .FirstOrDefaultAsync(cancellationToken);
 
-        return new
+        return JsonSerializer.SerializeToElement(
+            new
             {
                 CurrentTerm = currentTerm,
                 Counts = new
@@ -78,6 +96,7 @@ public sealed class DashboardController(AppDbContext db) : ControllerBase
                             cancellationToken),
                     Users = await db.Users.CountAsync(cancellationToken)
                 }
-        };
+            },
+            jsonOptions.Value.JsonSerializerOptions);
     }
 }

src/Jiaowu.Api/Controllers/ExamsController.cs

@@ -2,6 +2,7 @@ using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Exams;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -16,7 +17,8 @@ namespace Jiaowu.Api.Controllers;
 public sealed class ExamsController(
     AppDbContext db,
     ICurrentUserDataScope currentUserDataScope,
-    ExamArrangementService examArrangementService) : ControllerBase
+    ExamArrangementService examArrangementService,
+    IAppCache cache) : ControllerBase
 {
     private const string Managers =
         SystemRoles.SuperAdmin + "," + SystemRoles.AcademicAdmin;
@@ -610,6 +612,7 @@ public sealed class ExamsController(
         try
         {
             await db.SaveChangesAsync(token);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, token);
             return created ? Created(string.Empty, new { id }) : NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/PersonnelController.cs

@@ -3,6 +3,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity;
@@ -17,7 +18,8 @@ namespace Jiaowu.Api.Controllers;
 public sealed class PersonnelController(
     AppDbContext db,
     ICurrentUserDataScope currentUserDataScope,
-    UserManager<ApplicationUser> userManager) : ControllerBase
+    UserManager<ApplicationUser> userManager,
+    IAppCache cache) : ControllerBase
 {
     private const string ReadRoles =
         SystemRoles.SuperAdmin + "," +
@@ -209,6 +211,9 @@ public sealed class PersonnelController(
                 teacher.UserId = user.Id;
                 await db.SaveChangesAsync(cancellationToken);
                 await transaction.CommitAsync(cancellationToken);
+                await cache.RemoveByTagAsync(
+                    AppCacheTags.Timetables,
+                    cancellationToken);
                 return Ok(new { user.Id, UserName = userName });
             },
             cancellationToken);
@@ -429,6 +434,9 @@ public sealed class PersonnelController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Timetables,
+                cancellationToken);
             return Created(string.Empty, new { id });
         }
         catch (DbUpdateException)
@@ -442,6 +450,9 @@ public sealed class PersonnelController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Timetables,
+                cancellationToken);
             return NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/PersonnelExcelController.cs

@@ -1,6 +1,7 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -14,7 +15,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/personnel")]
 public sealed class PersonnelExcelController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string ReadRoles =
         SystemRoles.SuperAdmin + "," +
@@ -142,6 +144,9 @@ public sealed class PersonnelExcelController(
                     }
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.Timetables,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/ScheduleSettingsController.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -11,7 +12,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize(Roles = SystemRoles.SuperAdmin + "," + SystemRoles.AcademicAdmin)]
 [Route("api/schedules")]
-public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
+public sealed class ScheduleSettingsController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     [HttpGet("time-slots")]
     public async Task<ActionResult> GetTimeSlots(
@@ -65,6 +66,7 @@ public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
             IsEnabled = request.IsEnabled
         }));
         await db.SaveChangesAsync(cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
         return NoContent();
     }
 

src/Jiaowu.Api/Controllers/StatisticsController.cs

@@ -1,6 +1,8 @@
+using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -14,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/statistics")]
 public sealed class StatisticsController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache appCache) : ControllerBase
 {
     private const string ViewerRoles =
         SystemRoles.SuperAdmin + "," +
@@ -34,14 +37,49 @@ public sealed class StatisticsController(
     // ── 1. Student Statistics ────────────────────────────────────────
 
     [HttpGet("students/summary")]
-    public async Task<ActionResult<object>> GetStudentSummary(
+    public Task<ActionResult<object>> GetStudentSummary(
         Guid? collegeId, Guid? majorId, Guid? classId,
         int? grade, int? enrollmentYear,
+        CancellationToken cancellationToken) =>
+        GetStudentSummaryCore(
+            collegeId,
+            majorId,
+            classId,
+            grade,
+            enrollmentYear,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetStudentSummaryCore(
+        Guid? collegeId, Guid? majorId, Guid? classId,
+        int? grade, int? enrollmentYear,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "students",
+                    effectiveCollegeId,
+                    KeyPart(majorId),
+                    KeyPart(classId),
+                    KeyPart(grade),
+                    KeyPart(enrollmentYear)),
+                token => GetStudentSummaryCore(
+                    collegeId,
+                    majorId,
+                    classId,
+                    grade,
+                    enrollmentYear,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var baseQuery = db.Students.AsNoTracking()
             .Where(s => effectiveCollegeId == null ||
                 s.AdministrativeClass!.Major!.CollegeId == effectiveCollegeId)
@@ -112,8 +150,16 @@ public sealed class StatisticsController(
         int? grade, int? enrollmentYear,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetStudentSummary(collegeId, majorId, classId, grade, enrollmentYear, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetStudentSummaryCore(
+            collegeId,
+            majorId,
+            classId,
+            grade,
+            enrollmentYear,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("学生统计", new()
         {
             { "各学院人数", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.count }) },
@@ -128,13 +174,41 @@ public sealed class StatisticsController(
     // ── 2. Course Statistics ─────────────────────────────────────────
 
     [HttpGet("courses/summary")]
-    public async Task<ActionResult<object>> GetCourseSummary(
+    public Task<ActionResult<object>> GetCourseSummary(
         Guid? collegeId, Guid? categoryId, CourseNature? nature,
+        CancellationToken cancellationToken) =>
+        GetCourseSummaryCore(
+            collegeId,
+            categoryId,
+            nature,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetCourseSummaryCore(
+        Guid? collegeId, Guid? categoryId, CourseNature? nature,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "courses",
+                    effectiveCollegeId,
+                    KeyPart(categoryId),
+                    KeyPart(nature)),
+                token => GetCourseSummaryCore(
+                    collegeId,
+                    categoryId,
+                    nature,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var baseQuery = db.Courses.AsNoTracking()
             .Where(c => effectiveCollegeId == null || c.CollegeId == effectiveCollegeId)
             .Where(c => categoryId == null || c.CourseCategoryId == categoryId)
@@ -184,8 +258,14 @@ public sealed class StatisticsController(
         Guid? collegeId, Guid? categoryId, CourseNature? nature,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetCourseSummary(collegeId, categoryId, nature, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetCourseSummaryCore(
+            collegeId,
+            categoryId,
+            nature,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("课程统计", new()
         {
             { "各学院课程数", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.count }) },
@@ -199,13 +279,46 @@ public sealed class StatisticsController(
     // ── 3. Grade Statistics ──────────────────────────────────────────
 
     [HttpGet("grades/summary")]
-    public async Task<ActionResult<object>> GetGradeSummary(
+    public Task<ActionResult<object>> GetGradeSummary(
         Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
-        Guid? courseId, CancellationToken cancellationToken)
+        Guid? courseId, CancellationToken cancellationToken) =>
+        GetGradeSummaryCore(
+            academicTermId,
+            collegeId,
+            majorId,
+            classId,
+            courseId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetGradeSummaryCore(
+        Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
+        Guid? courseId, bool useCache, CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "grades",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(majorId),
+                    KeyPart(classId),
+                    KeyPart(courseId)),
+                token => GetGradeSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    majorId,
+                    classId,
+                    courseId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var recordsQuery = db.GradeRecords.AsNoTracking()
             .Where(r => r.GradeSheet!.Status == GradeSheetStatus.Published)
             .Where(r => academicTermId == null || r.GradeSheet!.TeachingTask!.AcademicTermId == academicTermId)
@@ -302,8 +415,16 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
         Guid? courseId, CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetGradeSummary(academicTermId, collegeId, majorId, classId, courseId, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetGradeSummaryCore(
+            academicTermId,
+            collegeId,
+            majorId,
+            classId,
+            courseId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("成绩统计", new()
         {
             { "分数段分布", ((IEnumerable<dynamic>)data.scoreDistribution).Select(x => new object?[] { x.label, x.count }) },
@@ -317,13 +438,41 @@ public sealed class StatisticsController(
     // ── 4. Pass Rate Statistics ──────────────────────────────────────
 
     [HttpGet("pass-rates/summary")]
-    public async Task<ActionResult<object>> GetPassRateSummary(
+    public Task<ActionResult<object>> GetPassRateSummary(
         Guid? academicTermId, Guid? collegeId, Guid? courseId,
+        CancellationToken cancellationToken) =>
+        GetPassRateSummaryCore(
+            academicTermId,
+            collegeId,
+            courseId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetPassRateSummaryCore(
+        Guid? academicTermId, Guid? collegeId, Guid? courseId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "pass-rates",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(courseId)),
+                token => GetPassRateSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    courseId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var recordsQuery = db.GradeRecords.AsNoTracking()
             .Where(r => r.GradeSheet!.Status == GradeSheetStatus.Published)
             .Where(r => academicTermId == null || r.GradeSheet!.TeachingTask!.AcademicTermId == academicTermId)
@@ -425,8 +574,14 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId, Guid? courseId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetPassRateSummary(academicTermId, collegeId, courseId, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetPassRateSummaryCore(
+            academicTermId,
+            collegeId,
+            courseId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("通过率统计", new()
         {
             { "各学院通过率", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.passRate, x.total }) },
@@ -439,13 +594,38 @@ public sealed class StatisticsController(
     // ── 5. Teacher Workload Statistics ───────────────────────────────
 
     [HttpGet("teacher-workload/summary")]
-    public async Task<ActionResult<object>> GetTeacherWorkloadSummary(
+    public Task<ActionResult<object>> GetTeacherWorkloadSummary(
         Guid? academicTermId, Guid? collegeId,
+        CancellationToken cancellationToken) =>
+        GetTeacherWorkloadSummaryCore(
+            academicTermId,
+            collegeId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetTeacherWorkloadSummaryCore(
+        Guid? academicTermId, Guid? collegeId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "teacher-workload",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId)),
+                token => GetTeacherWorkloadSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var tasks = await db.TeachingTaskTeachers.AsNoTracking()
             .Where(tt => academicTermId == null || tt.TeachingTask!.AcademicTermId == academicTermId)
             .Where(tt => effectiveCollegeId == null || tt.Teacher!.CollegeId == effectiveCollegeId)
@@ -524,8 +704,13 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetTeacherWorkloadSummary(academicTermId, collegeId, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetTeacherWorkloadSummaryCore(
+            academicTermId,
+            collegeId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("教师工作量统计", new()
         {
             { "教师明细", ((IEnumerable<dynamic>)data.byTeacher).Select(x => new object?[] { x.teacherName, x.teacherNumber, x.collegeName, x.title, x.totalHours, x.courseCount, x.taskCount }) },
@@ -537,10 +722,39 @@ public sealed class StatisticsController(
     // ── 6. Classroom Utilization Statistics ──────────────────────────
 
     [HttpGet("classroom-utilization/summary")]
-    public async Task<ActionResult<object>> GetClassroomUtilizationSummary(
+    public Task<ActionResult<object>> GetClassroomUtilizationSummary(
         Guid? academicTermId, Guid? buildingId, Guid? campusId,
+        CancellationToken cancellationToken) =>
+        GetClassroomUtilizationSummaryCore(
+            academicTermId,
+            buildingId,
+            campusId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetClassroomUtilizationSummaryCore(
+        Guid? academicTermId, Guid? buildingId, Guid? campusId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "classroom-utilization",
+                    RestrictedCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(buildingId),
+                    KeyPart(campusId)),
+                token => GetClassroomUtilizationSummaryCore(
+                    academicTermId,
+                    buildingId,
+                    campusId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         // Find published schedule plan
         var planQuery = db.SchedulePlans.AsNoTracking()
             .Where(p => p.Status == SchedulePlanStatus.Published);
@@ -713,8 +927,14 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? buildingId, Guid? campusId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetClassroomUtilizationSummary(academicTermId, buildingId, campusId, cancellationToken)
-            .ConfigureAwait(false)).Value!;
+        var summary = await GetClassroomUtilizationSummaryCore(
+            academicTermId,
+            buildingId,
+            campusId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("教室利用率统计", new()
         {
             { "各教学楼", ((IEnumerable<dynamic>)data.byBuilding).Select(x => new object?[] { x.buildingName, x.totalClassrooms, x.utilizationRate, x.totalUsedPeriods, x.totalAvailablePeriods }) },
@@ -727,6 +947,50 @@ public sealed class StatisticsController(
 
     // ── Helpers ──────────────────────────────────────────────────────
 
+    private async Task<ActionResult<object>> GetCachedSummaryAsync(
+        string key,
+        Func<CancellationToken, Task<ActionResult<object>>> factory,
+        CancellationToken cancellationToken)
+    {
+        var value = await appCache.GetOrCreateAsync(
+            key,
+            async token =>
+            {
+                var source = await factory(token);
+                if (source.Result is not null || source.Value is null)
+                    throw new InvalidOperationException(
+                        "Statistics cache source did not return a successful value.");
+
+                return JsonSerializer.SerializeToElement(
+                    source.Value,
+                    source.Value.GetType());
+            },
+            AppCacheProfile.Analytics,
+            [AppCacheTags.Analytics],
+            cancellationToken);
+        return value;
+    }
+
+    private string StatisticsKey(
+        string area,
+        Guid? effectiveCollegeId,
+        params string?[] filters) =>
+        AppCacheKeys.Statistics(
+            area,
+            currentUserDataScope.Current.Scope.ToString(),
+            effectiveCollegeId,
+            filters);
+
+    private static string KeyPart(Guid? value) =>
+        value?.ToString("N") ?? "-";
+
+    private static string KeyPart(int? value) =>
+        value?.ToString(System.Globalization.CultureInfo.InvariantCulture) ?? "-";
+
+    private static string KeyPart<TEnum>(TEnum? value)
+        where TEnum : struct, Enum =>
+        value?.ToString() ?? "-";
+
     private FileContentResult ExportSummary(
         string title,
         Dictionary<string, IEnumerable<object?[]>> sheets)

src/Jiaowu.Api/Controllers/TeachingTasksController.cs

@@ -4,6 +4,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
@@ -17,7 +18,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/teaching-tasks")]
 public sealed class TeachingTasksController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string ManagementRoles =
         SystemRoles.SuperAdmin + "," +
@@ -389,6 +391,7 @@ public sealed class TeachingTasksController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return Ok(new { AffectedCount = tasks.Count });
         }
         catch (DbUpdateException)
@@ -544,6 +547,9 @@ public sealed class TeachingTasksController(
                 db.TeachingTasks.AddRange(created);
                 await db.SaveChangesAsync(cancellationToken);
                 await transaction.CommitAsync(cancellationToken);
+                await cache.RemoveByTagAsync(
+                    AppCacheTags.Timetables,
+                    cancellationToken);
                 return Ok(new
                 {
                     BatchCode = batchCode,
@@ -737,6 +743,7 @@ public sealed class TeachingTasksController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return created ? Created(string.Empty, new { id }) : NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/TimetablesController.cs

@@ -1,6 +1,7 @@
 using System.Security.Claims;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Timetables;
@@ -14,74 +15,24 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/timetables")]
 public sealed class TimetablesController(
     AppDbContext db,
-    TimetableDataService timetableDataService) : ControllerBase
+    TimetableDataService timetableDataService,
+    IAppCache cache) : ControllerBase
 {
     [HttpGet("options")]
     [AllowAnonymous]
     public async Task<ActionResult> GetOptions(CancellationToken cancellationToken)
     {
-        var terms = await db.AcademicTerms.AsNoTracking()
-            .Where(x => x.IsEnabled)
-            .OrderByDescending(x => x.StartDate)
-            .Select(x => new
-            {
-                x.Id,
-                x.Name,
-                x.AcademicYear,
-                x.Season,
-                x.StartDate,
-                x.EndDate,
-                x.IsCurrent,
-                x.IsArchived,
-                 HasPublishedTimetable = db.SchedulePlans.Any(plan =>
-                     plan.AcademicTermId == x.Id &&
-                     plan.Status == SchedulePlanStatus.Published) ||
-                     db.TeachingTasks.Any(task =>
-                         task.AcademicTermId == x.Id &&
-                         task.Status == TeachingTaskStatus.Published &&
-                         task.SchedulingMode == TeachingTaskSchedulingMode.Flexible)
-            })
-            .ToListAsync(cancellationToken);
-        var defaultTermId = terms.FirstOrDefault(x => x.IsCurrent)?.Id
-            ?? terms.FirstOrDefault(x => x.HasPublishedTimetable)?.Id;
-        var classes = await db.AdministrativeClasses.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
-            .OrderByDescending(x => x.Grade)
-            .ThenBy(x => x.Code)
-            .Select(x => new
-            {
-                x.Id,
-                x.Code,
-                 x.Name,
-                 x.Grade,
-                 x.MajorId,
-                 MajorName = x.Major!.Name,
-                 CollegeId = x.Major.CollegeId,
-                 CollegeName = x.Major.College!.Name,
-                 HasPublishedTimetable = defaultTermId.HasValue &&
-                     (db.ScheduleEntries.Any(entry =>
-                          entry.SchedulePlan!.AcademicTermId == defaultTermId.Value &&
-                          entry.SchedulePlan.Status == SchedulePlanStatus.Published &&
-                          entry.TeachingTask!.Classes.Any(item =>
-                              item.AdministrativeClassId == x.Id)) ||
-                      db.TeachingTasks.Any(task =>
-                          task.AcademicTermId == defaultTermId.Value &&
-                          task.Status == TeachingTaskStatus.Published &&
-                          task.SchedulingMode == TeachingTaskSchedulingMode.Flexible &&
-                          task.Classes.Any(item => item.AdministrativeClassId == x.Id)))
-             })
-             .ToListAsync(cancellationToken);
-        var colleges = await db.Colleges.AsNoTracking()
-            .Where(x => x.IsEnabled)
-            .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name })
-            .ToListAsync(cancellationToken);
-        var majors = await db.Majors.AsNoTracking()
-            .Where(x => x.IsEnabled && x.College!.IsEnabled)
-            .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.CollegeId })
-            .ToListAsync(cancellationToken);
-        return Ok(new { Terms = terms, Colleges = colleges, Majors = majors, Classes = classes });
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.TimetableOptions,
+            LoadOptionsAsync,
+            AppCacheProfile.ReferenceData,
+            [
+                AppCacheTags.BaseData,
+                AppCacheTags.Timetables,
+                AppCacheTags.TimetableOptions
+            ],
+            cancellationToken);
+        return Ok(result);
     }
 
     [HttpGet("classes/{classId:guid}")]
@@ -99,14 +50,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Teacher,
             teacherId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         return result is null ? NotFound() : Ok(result);
     }
@@ -118,14 +65,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Teacher,
             teacherId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         if (result is null) return NotFound();
         return ExcelFile(result);
@@ -138,14 +81,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Class,
             classId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         if (result is null) return NotFound();
         return ExcelFile(result);
@@ -269,7 +208,8 @@ public sealed class TimetablesController(
         CancellationToken cancellationToken,
         TimetableStudentDto? student = null)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = studentId.HasValue || student is not null
+            ? await timetableDataService.BuildAsync(
                 TimetableResourceType.Class,
                 classId,
                 academicTermId,
@@ -277,10 +217,102 @@ public sealed class TimetablesController(
                 false,
                 studentId,
                 student,
+                cancellationToken)
+            : await GetPublishedTimetableAsync(
+                TimetableResourceType.Class,
+                classId,
+                academicTermId,
                 cancellationToken);
          return result is null ? NotFound() : Ok(result);
      }
 
+    private Task<TimetableData?> GetPublishedTimetableAsync(
+        TimetableResourceType resourceType,
+        Guid resourceId,
+        Guid? academicTermId,
+        CancellationToken cancellationToken) =>
+        cache.GetOrCreateAsync(
+            AppCacheKeys.PublishedTimetable(
+                resourceType.ToString().ToLowerInvariant(),
+                resourceId,
+                academicTermId),
+            token => timetableDataService.BuildAsync(
+                resourceType,
+                resourceId,
+                academicTermId,
+                null,
+                false,
+                null,
+                null,
+                token),
+            AppCacheProfile.PublishedTimetable,
+            [AppCacheTags.BaseData, AppCacheTags.Timetables],
+            cancellationToken);
+
+    private async Task<TimetableOptionsResponse> LoadOptionsAsync(
+        CancellationToken cancellationToken)
+    {
+        var terms = await db.AcademicTerms.AsNoTracking()
+            .Where(x => x.IsEnabled)
+            .OrderByDescending(x => x.StartDate)
+            .Select(x => new TimetableTermOption(
+                x.Id,
+                x.Name,
+                x.AcademicYear,
+                x.Season,
+                x.StartDate,
+                x.EndDate,
+                x.IsCurrent,
+                x.IsArchived,
+                db.SchedulePlans.Any(plan =>
+                    plan.AcademicTermId == x.Id &&
+                    plan.Status == SchedulePlanStatus.Published) ||
+                db.TeachingTasks.Any(task =>
+                    task.AcademicTermId == x.Id &&
+                    task.Status == TeachingTaskStatus.Published &&
+                    task.SchedulingMode == TeachingTaskSchedulingMode.Flexible)))
+            .ToListAsync(cancellationToken);
+        var defaultTermId = terms.FirstOrDefault(x => x.IsCurrent)?.Id
+            ?? terms.FirstOrDefault(x => x.HasPublishedTimetable)?.Id;
+        var classes = await db.AdministrativeClasses.AsNoTracking()
+            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
+            .OrderByDescending(x => x.Grade)
+            .ThenBy(x => x.Code)
+            .Select(x => new TimetableClassOption(
+                x.Id,
+                x.Code,
+                x.Name,
+                x.Grade,
+                x.MajorId,
+                x.Major!.Name,
+                x.Major.CollegeId,
+                x.Major.College!.Name,
+                defaultTermId.HasValue &&
+                (db.ScheduleEntries.Any(entry =>
+                     entry.SchedulePlan!.AcademicTermId == defaultTermId.Value &&
+                     entry.SchedulePlan.Status == SchedulePlanStatus.Published &&
+                     entry.TeachingTask!.Classes.Any(item =>
+                         item.AdministrativeClassId == x.Id)) ||
+                 db.TeachingTasks.Any(task =>
+                     task.AcademicTermId == defaultTermId.Value &&
+                     task.Status == TeachingTaskStatus.Published &&
+                     task.SchedulingMode == TeachingTaskSchedulingMode.Flexible &&
+                     task.Classes.Any(item => item.AdministrativeClassId == x.Id)))))
+            .ToListAsync(cancellationToken);
+        var colleges = await db.Colleges.AsNoTracking()
+            .Where(x => x.IsEnabled)
+            .OrderBy(x => x.Code)
+            .Select(x => new TimetableCollegeOption(x.Id, x.Code, x.Name))
+            .ToListAsync(cancellationToken);
+        var majors = await db.Majors.AsNoTracking()
+            .Where(x => x.IsEnabled && x.College!.IsEnabled)
+            .OrderBy(x => x.Code)
+            .Select(x => new TimetableMajorOption(
+                x.Id, x.Code, x.Name, x.CollegeId))
+            .ToListAsync(cancellationToken);
+        return new TimetableOptionsResponse(terms, colleges, majors, classes);
+    }
+
     private ActionResult ExcelFile(TimetableData result)
     {
         var bytes = TimetableExcelExporter.Create(result);
@@ -296,3 +328,39 @@ public sealed class TimetablesController(
         return value.Trim();
     }
 }
+
+public sealed record TimetableOptionsResponse(
+    IReadOnlyList<TimetableTermOption> Terms,
+    IReadOnlyList<TimetableCollegeOption> Colleges,
+    IReadOnlyList<TimetableMajorOption> Majors,
+    IReadOnlyList<TimetableClassOption> Classes);
+
+public sealed record TimetableTermOption(
+    Guid Id,
+    string Name,
+    string AcademicYear,
+    TermSeason Season,
+    DateOnly StartDate,
+    DateOnly EndDate,
+    bool IsCurrent,
+    bool IsArchived,
+    bool HasPublishedTimetable);
+
+public sealed record TimetableCollegeOption(Guid Id, string Code, string Name);
+
+public sealed record TimetableMajorOption(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId);
+
+public sealed record TimetableClassOption(
+    Guid Id,
+    string Code,
+    string Name,
+    int Grade,
+    Guid MajorId,
+    string MajorName,
+    Guid CollegeId,
+    string CollegeName,
+    bool HasPublishedTimetable);

src/Jiaowu.Api/Infrastructure/Caching/AppCache.cs

@@ -0,0 +1,196 @@
+using Microsoft.Extensions.Caching.Hybrid;
+using StackExchange.Redis;
+
+namespace Jiaowu.Api.Infrastructure.Caching;
+
+public enum AppCacheProfile
+{
+    ReferenceData,
+    PublishedTimetable,
+    Analytics
+}
+
+public interface IAppCache
+{
+    Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken);
+
+    ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default);
+}
+
+public sealed class HybridAppCache(
+    HybridCache cache,
+    AppCacheOptions options,
+    IHostEnvironment environment,
+    ILogger<HybridAppCache> logger) : IAppCache
+{
+    private readonly string prefix = BuildPrefix(options.KeyPrefix, environment.EnvironmentName);
+
+    public async Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken)
+    {
+        if (!options.Enabled)
+            return await factory(cancellationToken);
+
+        var sourceCompleted = false;
+        T? sourceValue = default;
+        try
+        {
+            return await cache.GetOrCreateAsync(
+                $"{prefix}:{key}",
+                async token =>
+                {
+                    sourceValue = await factory(token);
+                    sourceCompleted = true;
+                    return sourceValue;
+                },
+                GetEntryOptions(profile),
+                tags.Select(tag => $"{prefix}:tag:{tag}"),
+                cancellationToken);
+        }
+        catch (RedisException exception)
+        {
+            logger.LogWarning(
+                exception,
+                "Redis cache operation failed for {CacheKey}; using the source directly.",
+                key);
+            if (sourceCompleted)
+                return sourceValue!;
+            return await factory(cancellationToken);
+        }
+    }
+
+    public async ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default)
+    {
+        if (!options.Enabled)
+            return;
+
+        try
+        {
+            await cache.RemoveByTagAsync(
+                $"{prefix}:tag:{tag}",
+                cancellationToken);
+        }
+        catch (RedisException exception)
+        {
+            logger.LogWarning(
+                exception,
+                "Redis cache invalidation failed for tag {CacheTag}; TTL will bound staleness.",
+                tag);
+        }
+    }
+
+    private HybridCacheEntryOptions GetEntryOptions(AppCacheProfile profile) =>
+        profile switch
+        {
+            AppCacheProfile.ReferenceData => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.ReferenceExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.ReferenceLocalExpirationSeconds)
+            },
+            AppCacheProfile.PublishedTimetable => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.TimetableExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.TimetableLocalExpirationSeconds)
+            },
+            AppCacheProfile.Analytics => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.AnalyticsExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.AnalyticsLocalExpirationSeconds)
+            },
+            _ => throw new ArgumentOutOfRangeException(nameof(profile), profile, null)
+        };
+
+    private static string BuildPrefix(string configuredPrefix, string environmentName)
+    {
+        var prefixValue = string.IsNullOrWhiteSpace(configuredPrefix)
+            ? "jiaowu:v1"
+            : configuredPrefix.Trim().Trim(':');
+        var environmentValue = string.Concat(
+            environmentName.Trim().ToLowerInvariant()
+                .Select(character => char.IsLetterOrDigit(character) ? character : '-'));
+        return $"{prefixValue}:{environmentValue}";
+    }
+}
+
+public sealed class NoOpAppCache : IAppCache
+{
+    public static NoOpAppCache Instance { get; } = new();
+
+    private NoOpAppCache()
+    {
+    }
+
+    public Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken) =>
+        factory(cancellationToken);
+
+    public ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default) =>
+        ValueTask.CompletedTask;
+}
+
+public static class AppCacheKeys
+{
+    public const string ActivationOptions = "auth:activation-options";
+    public const string Dashboard = "dashboard:summary";
+    public const string TimetableOptions = "timetable:options";
+
+    public static string BaseData(string kind) => $"base-data:{kind}";
+
+    public static string PublishedTimetable(
+        string resourceType,
+        Guid resourceId,
+        Guid? academicTermId) =>
+        $"timetable:published:{academicTermId?.ToString("N") ?? "current"}:" +
+        $"{resourceType}:{resourceId:N}";
+
+    public static string Statistics(
+        string area,
+        string dataScope,
+        Guid? effectiveCollegeId,
+        params string?[] filters)
+    {
+        static string Normalize(string? value) =>
+            string.IsNullOrWhiteSpace(value)
+                ? "-"
+                : value.Trim().ToLowerInvariant();
+
+        var filterPart = filters.Length == 0
+            ? "all"
+            : string.Join(':', filters.Select(Normalize));
+        return $"statistics:{Normalize(area)}:scope:{Normalize(dataScope)}:" +
+               $"college:{effectiveCollegeId?.ToString("N") ?? "all"}:{filterPart}";
+    }
+}
+
+public static class AppCacheTags
+{
+    public const string BaseData = "base-data";
+    public const string Analytics = "analytics";
+    public const string Timetables = "timetables";
+    public const string TimetableOptions = "timetable:options";
+
+    public static string Timetable(Guid academicTermId) =>
+        $"timetable:term:{academicTermId:N}";
+}

src/Jiaowu.Api/Infrastructure/Caching/AppCacheOptions.cs

@@ -0,0 +1,16 @@
+namespace Jiaowu.Api.Infrastructure.Caching;
+
+public sealed class AppCacheOptions
+{
+    public const string SectionName = "Cache";
+
+    public bool Enabled { get; set; } = true;
+    public string KeyPrefix { get; set; } = "jiaowu:v1";
+    public int ReferenceExpirationMinutes { get; set; } = 30;
+    public int ReferenceLocalExpirationSeconds { get; set; } = 120;
+    public int TimetableExpirationMinutes { get; set; } = 10;
+    public int TimetableLocalExpirationSeconds { get; set; } = 30;
+    public int AnalyticsExpirationMinutes { get; set; } = 3;
+    public int AnalyticsLocalExpirationSeconds { get; set; } = 30;
+    public int MaximumPayloadKilobytes { get; set; } = 2048;
+}

src/Jiaowu.Api/Infrastructure/Persistence/AppDbContext.cs

@@ -101,6 +101,12 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         configurationBuilder.Properties<DateOnly>()
             .HaveConversion<DateOnlyDateTimeConverter>()
             .HaveColumnType("date");
+
+        // Connector/NET returns MySQL TIME values as TimeSpan. Convert at the
+        // provider boundary so schedule time slots can still use TimeOnly.
+        configurationBuilder.Properties<TimeOnly>()
+            .HaveConversion<TimeOnlyTimeSpanConverter>()
+            .HaveColumnType("time");
     }
 
     protected override void OnModelCreating(ModelBuilder builder)
@@ -931,3 +937,8 @@ public sealed class DateOnlyDateTimeConverter()
     : ValueConverter<DateOnly, DateTime>(
         date => date.ToDateTime(TimeOnly.MinValue),
         value => DateOnly.FromDateTime(value));
+
+public sealed class TimeOnlyTimeSpanConverter()
+    : ValueConverter<TimeOnly, TimeSpan>(
+        time => time.ToTimeSpan(),
+        value => TimeOnly.FromTimeSpan(value));

src/Jiaowu.Api/Infrastructure/Scheduling/SchedulePublishJobs.cs

@@ -1,6 +1,7 @@
 using System.Threading.Channels;
 using System.Diagnostics.CodeAnalysis;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.EntityFrameworkCore;
 
@@ -103,6 +104,7 @@ public sealed class SchedulePublishJobWorker(
 public sealed class SchedulePublishJobProcessor(
     AppDbContext db,
     SchedulePlanPublisher publisher,
+    IAppCache cache,
     ILogger<SchedulePublishJobProcessor> logger)
 {
     public async Task ProcessAsync(Guid jobId, CancellationToken stoppingToken)
@@ -177,6 +179,7 @@ public sealed class SchedulePublishJobProcessor(
                 },
                 stoppingToken);
 
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, stoppingToken);
             logger.LogInformation(
                 "Schedule publish job {JobId} published plan {SchedulePlanId}.",
                 jobId,

src/Jiaowu.Api/Jiaowu.Api.csproj

@@ -23,6 +23,8 @@
     <PackageReference Include="ClosedXML" Version="0.105.0" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="10.0.10" />
     <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="10.0.10" />
+    <PackageReference Include="Microsoft.Extensions.Caching.Hybrid" Version="10.1.0" />
+    <PackageReference Include="Microsoft.Extensions.Caching.StackExchangeRedis" Version="10.0.10" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.10">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>

src/Jiaowu.Api/Program.cs

@@ -3,6 +3,7 @@ using System.Text.Json.Serialization;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Configuration;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Exams;
 using Jiaowu.Api.Infrastructure.Middleware;
 using Jiaowu.Api.Infrastructure.Persistence;
@@ -12,6 +13,7 @@ using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.AspNetCore.RateLimiting;
 using Microsoft.Data.Sqlite;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Caching.Distributed;
 using Microsoft.IdentityModel.Tokens;
 using Microsoft.OpenApi.Models;
 using System.Threading.RateLimiting;
@@ -61,6 +63,9 @@ if (seedDemoData && builder.Environment.IsDevelopment())
 var databaseOptions = builder.Configuration
     .GetSection(DatabaseOptions.SectionName)
     .Get<DatabaseOptions>() ?? new DatabaseOptions();
+var cacheOptions = builder.Configuration
+    .GetSection(AppCacheOptions.SectionName)
+    .Get<AppCacheOptions>() ?? new AppCacheOptions();
 
 if (databaseOptions.Provider.Equals("SQLite", StringComparison.OrdinalIgnoreCase) &&
     !builder.Environment.IsDevelopment())
@@ -82,7 +87,28 @@ if (databaseOptions.CommandTimeoutSeconds is < 5 or > 300)
         "Database:CommandTimeoutSeconds 必须在 5 到 300 秒之间。");
 }
 
+if (cacheOptions.ReferenceExpirationMinutes is < 1 or > 1440 ||
+    cacheOptions.TimetableExpirationMinutes is < 1 or > 1440 ||
+    cacheOptions.AnalyticsExpirationMinutes is < 1 or > 1440 ||
+    cacheOptions.ReferenceLocalExpirationSeconds is < 1 or > 3600 ||
+    cacheOptions.TimetableLocalExpirationSeconds is < 1 or > 3600 ||
+    cacheOptions.AnalyticsLocalExpirationSeconds is < 1 or > 3600 ||
+    cacheOptions.MaximumPayloadKilobytes is < 64 or > 16384 ||
+    cacheOptions.ReferenceLocalExpirationSeconds >
+        cacheOptions.ReferenceExpirationMinutes * 60 ||
+    cacheOptions.TimetableLocalExpirationSeconds >
+        cacheOptions.TimetableExpirationMinutes * 60 ||
+    cacheOptions.AnalyticsLocalExpirationSeconds >
+        cacheOptions.AnalyticsExpirationMinutes * 60 ||
+    string.IsNullOrWhiteSpace(cacheOptions.KeyPrefix) ||
+    cacheOptions.KeyPrefix.Length > 100)
+{
+    throw new InvalidOperationException(
+        "Cache 缓存时间或 MaximumPayloadKilobytes 超出允许范围。");
+}
+
 builder.Services.AddSingleton(databaseOptions);
+builder.Services.AddSingleton(cacheOptions);
 builder.Services.AddDbContextPool<AppDbContext>(options =>
 {
     if (databaseOptions.Provider.Equals("SQLite", StringComparison.OrdinalIgnoreCase))
@@ -125,6 +151,19 @@ builder.Services.AddDbContextPool<AppDbContext>(options =>
     });
 });
 
+var redisConnectionString = builder.Configuration.GetConnectionString("Redis");
+if (cacheOptions.Enabled && !string.IsNullOrWhiteSpace(redisConnectionString))
+{
+    builder.Services.AddStackExchangeRedisCache(options =>
+        options.Configuration = redisConnectionString);
+}
+builder.Services.AddHybridCache(options =>
+{
+    options.MaximumKeyLength = 512;
+    options.MaximumPayloadBytes = cacheOptions.MaximumPayloadKilobytes * 1024;
+});
+builder.Services.AddSingleton<IAppCache, HybridAppCache>();
+
 builder.Services
     .AddIdentityCore<ApplicationUser>(options =>
     {
@@ -320,6 +359,7 @@ app.MapGet("/health/live", () => Results.Ok(new { Status = "healthy" }))
     .AllowAnonymous();
 app.MapGet("/health", CheckDatabaseHealthAsync).AllowAnonymous();
 app.MapGet("/health/ready", CheckDatabaseHealthAsync).AllowAnonymous();
+app.MapGet("/health/cache", CheckCacheHealthAsync).AllowAnonymous();
 app.MapFallback(async context =>
 {
     if (context.Request.Path.StartsWithSegments("/api") ||
@@ -383,4 +423,27 @@ static async Task<IResult> CheckDatabaseHealthAsync(
     }
 }
 
+static async Task<IResult> CheckCacheHealthAsync(
+    IServiceProvider services,
+    CancellationToken cancellationToken)
+{
+    var distributedCache = services.GetService<IDistributedCache>();
+    if (distributedCache is null)
+        return Results.Ok(new { Status = "disabled", Backend = "memory" });
+
+    try
+    {
+        await distributedCache.GetAsync(
+            "jiaowu:health:probe",
+            cancellationToken);
+        return Results.Ok(new { Status = "healthy", Backend = "redis" });
+    }
+    catch
+    {
+        return Results.Json(
+            new { Status = "unhealthy", Backend = "redis" },
+            statusCode: StatusCodes.Status503ServiceUnavailable);
+    }
+}
+
 public partial class Program;

src/Jiaowu.Api/appsettings.Development.json

@@ -5,6 +5,9 @@
   "ConnectionStrings": {
     "SQLite": "Data Source=data/jiaowu-dev.sqlite"
   },
+  "Cache": {
+    "Enabled": true
+  },
   "Jwt": {
     "Key": "jiaowu-development-secret-key-change-before-production",
     "ExpireMinutes": 480

src/Jiaowu.Api/appsettings.json

@@ -5,7 +5,19 @@
     "CommandTimeoutSeconds": 30
   },
   "ConnectionStrings": {
-    "MySql": ""
+    "MySql": "",
+    "Redis": ""
+  },
+  "Cache": {
+    "Enabled": true,
+    "KeyPrefix": "jiaowu:v1",
+    "ReferenceExpirationMinutes": 30,
+    "ReferenceLocalExpirationSeconds": 120,
+    "TimetableExpirationMinutes": 10,
+    "TimetableLocalExpirationSeconds": 30,
+    "AnalyticsExpirationMinutes": 3,
+    "AnalyticsLocalExpirationSeconds": 30,
+    "MaximumPayloadKilobytes": 2048
   },
   "Jwt": {
     "Issuer": "Jiaowu.Api",

tests/Jiaowu.Api.Tests/AppCacheTests.cs

@@ -0,0 +1,354 @@
+using System.Text.Json;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
+using Jiaowu.Api.Infrastructure.Timetables;
+using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Options;
+
+namespace Jiaowu.Api.Tests;
+
+public sealed class AppCacheTests
+{
+    [Fact]
+    public void Statistics_keys_isolate_data_scope_college_and_filters()
+    {
+        var firstCollege = Guid.NewGuid();
+        var secondCollege = Guid.NewGuid();
+        var term = Guid.NewGuid().ToString("N");
+
+        var first = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            firstCollege,
+            term,
+            "-");
+        var otherCollege = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            secondCollege,
+            term,
+            "-");
+        var otherScope = AppCacheKeys.Statistics(
+            "grades",
+            "All",
+            firstCollege,
+            term,
+            "-");
+        var otherFilter = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            firstCollege,
+            Guid.NewGuid().ToString("N"),
+            "-");
+
+        Assert.NotEqual(first, otherCollege);
+        Assert.NotEqual(first, otherScope);
+        Assert.NotEqual(first, otherFilter);
+        Assert.Equal(
+            first,
+            AppCacheKeys.Statistics(
+                " GRADES ",
+                "COLLEGE",
+                firstCollege,
+                term,
+                null));
+    }
+
+    [Fact]
+    public async Task Hybrid_cache_reuses_value_and_tag_invalidation_reloads_source()
+    {
+        await using var provider = CreateProvider(enabled: true);
+        var cache = provider.GetRequiredService<IAppCache>();
+        var sourceCalls = 0;
+        var key = $"test:{Guid.NewGuid():N}";
+
+        Task<int> Load(CancellationToken _)
+        {
+            sourceCalls++;
+            return Task.FromResult(sourceCalls);
+        }
+
+        var first = await cache.GetOrCreateAsync(
+            key,
+            Load,
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            CancellationToken.None);
+        var second = await cache.GetOrCreateAsync(
+            key,
+            Load,
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            CancellationToken.None);
+
+        Assert.Equal(1, first);
+        Assert.Equal(1, second);
+        Assert.Equal(1, sourceCalls);
+
+        await cache.RemoveByTagAsync(AppCacheTags.BaseData);
+        var afterInvalidation = await cache.GetOrCreateAsync(
+            key,
+            Load,
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            CancellationToken.None);
+
+        Assert.Equal(2, afterInvalidation);
+        Assert.Equal(2, sourceCalls);
+    }
+
+    [Fact]
+    public async Task Disabled_cache_always_uses_source()
+    {
+        await using var provider = CreateProvider(enabled: false);
+        var cache = provider.GetRequiredService<IAppCache>();
+        var sourceCalls = 0;
+
+        Task<int> Load(CancellationToken _)
+        {
+            sourceCalls++;
+            return Task.FromResult(sourceCalls);
+        }
+
+        var first = await cache.GetOrCreateAsync(
+            "disabled",
+            Load,
+            AppCacheProfile.ReferenceData,
+            [],
+            CancellationToken.None);
+        var second = await cache.GetOrCreateAsync(
+            "disabled",
+            Load,
+            AppCacheProfile.ReferenceData,
+            [],
+            CancellationToken.None);
+
+        Assert.Equal(1, first);
+        Assert.Equal(2, second);
+    }
+
+    [Fact]
+    public async Task Timetable_data_round_trips_through_distributed_cache()
+    {
+        IDistributedCache distributedCache = new SharedDistributedCache(
+            new MemoryDistributedCache(
+                Options.Create(new MemoryDistributedCacheOptions())));
+        var keyPrefix = $"tests:{Guid.NewGuid():N}";
+        await using var writer = CreateProvider(true, distributedCache, keyPrefix);
+        var source = CreateTimetableData();
+
+        await writer.GetRequiredService<IAppCache>().GetOrCreateAsync(
+            "timetable",
+            _ => Task.FromResult(source),
+            AppCacheProfile.PublishedTimetable,
+            [AppCacheTags.Timetables],
+            CancellationToken.None);
+
+        await using var reader = CreateProvider(true, distributedCache, keyPrefix);
+        var sourceCalled = false;
+        var result = await reader.GetRequiredService<IAppCache>().GetOrCreateAsync(
+            "timetable",
+            _ =>
+            {
+                sourceCalled = true;
+                return Task.FromResult(source);
+            },
+            AppCacheProfile.PublishedTimetable,
+            [AppCacheTags.Timetables],
+            CancellationToken.None);
+
+        Assert.False(sourceCalled);
+        Assert.Equal(source.Term.Id, result.Term.Id);
+        Assert.Equal(source.Plan!.Id, result.Plan!.Id);
+        Assert.Equal("缓存测试课程", result.Entries.Single().CourseName);
+        Assert.Equal(new TimeOnly(8, 45), result.Slots.Single().EndsAt);
+    }
+
+    [Fact]
+    public async Task Analytics_json_round_trips_through_distributed_cache()
+    {
+        IDistributedCache distributedCache = new SharedDistributedCache(
+            new MemoryDistributedCache(
+                Options.Create(new MemoryDistributedCacheOptions())));
+        var keyPrefix = $"tests:{Guid.NewGuid():N}";
+        var source = JsonSerializer.SerializeToElement(new
+        {
+            totals = new { totalCourses = 3 }
+        });
+
+        await using (var writer = CreateProvider(
+                         true,
+                         distributedCache,
+                         keyPrefix))
+        {
+            await writer.GetRequiredService<IAppCache>().GetOrCreateAsync(
+                "statistics:courses",
+                _ => Task.FromResult(source),
+                AppCacheProfile.Analytics,
+                [AppCacheTags.Analytics],
+                CancellationToken.None);
+        }
+
+        await using var reader = CreateProvider(
+            true,
+            distributedCache,
+            keyPrefix);
+        var sourceCalled = false;
+        var result = await reader.GetRequiredService<IAppCache>()
+            .GetOrCreateAsync(
+                "statistics:courses",
+                _ =>
+                {
+                    sourceCalled = true;
+                    return Task.FromResult(source);
+                },
+                AppCacheProfile.Analytics,
+                [AppCacheTags.Analytics],
+                CancellationToken.None);
+
+        Assert.False(sourceCalled);
+        Assert.Equal(
+            3,
+            result.GetProperty("totals")
+                .GetProperty("totalCourses")
+                .GetInt32());
+    }
+
+    private static ServiceProvider CreateProvider(
+        bool enabled,
+        IDistributedCache? distributedCache = null,
+        string? keyPrefix = null)
+    {
+        var services = new ServiceCollection();
+        services.AddLogging();
+        services.AddHybridCache();
+        if (distributedCache is not null)
+            services.AddSingleton(distributedCache);
+        services.AddSingleton(new AppCacheOptions
+        {
+            Enabled = enabled,
+            KeyPrefix = keyPrefix ?? $"tests:{Guid.NewGuid():N}"
+        });
+        services.AddSingleton<IHostEnvironment>(new TestHostEnvironment());
+        services.AddSingleton<IAppCache, HybridAppCache>();
+        return services.BuildServiceProvider();
+    }
+
+    private static TimetableData CreateTimetableData()
+    {
+        var termId = Guid.NewGuid();
+        var planId = Guid.NewGuid();
+        var taskId = Guid.NewGuid();
+        return new TimetableData(
+            new TimetableTermDto(
+                termId,
+                "2026-2027 学年第一学期",
+                "2026-2027",
+                TermSeason.Autumn,
+                new DateOnly(2026, 9, 1),
+                new DateOnly(2027, 1, 20),
+                true),
+            new TimetableSubjectDto(
+                Guid.NewGuid(),
+                "SE202601",
+                "软件工程 2026 级 1 班",
+                TimetableResourceType.Class,
+                2026,
+                Guid.NewGuid(),
+                "软件工程",
+                Guid.NewGuid(),
+                "计算机学院",
+                null,
+                null,
+                null),
+            null,
+            null,
+            new TimetablePlanDto(
+                planId,
+                "正式课表",
+                "V1",
+                SchedulePlanStatus.Published,
+                DateTime.UtcNow,
+                DateTime.UtcNow),
+            [
+                new TimetableSlotDto(
+                    1,
+                    "第 1 节",
+                    new TimeOnly(8, 0),
+                    new TimeOnly(8, 45))
+            ],
+            [
+                new TimetableEntryDto(
+                    Guid.NewGuid(),
+                    taskId,
+                    "TASK-001",
+                    "缓存测试教学班",
+                    "CACHE-01",
+                    "缓存测试课程",
+                    ["测试教师"],
+                    ["软件工程 2026 级 1 班"],
+                    "第一教学楼 101",
+                    "第一教学楼",
+                    "主校区",
+                    1,
+                    1,
+                    2,
+                    1,
+                    16,
+                    WeekPattern.All,
+                    null)
+            ],
+            [],
+            []);
+    }
+
+    private sealed class TestHostEnvironment : IHostEnvironment
+    {
+        public string EnvironmentName { get; set; } = Environments.Development;
+        public string ApplicationName { get; set; } = nameof(AppCacheTests);
+        public string ContentRootPath { get; set; } = AppContext.BaseDirectory;
+        public IFileProvider ContentRootFileProvider { get; set; } = new NullFileProvider();
+    }
+
+    private sealed class SharedDistributedCache(IDistributedCache inner)
+        : IDistributedCache
+    {
+        public byte[]? Get(string key) => inner.Get(key);
+
+        public Task<byte[]?> GetAsync(
+            string key,
+            CancellationToken token = default) =>
+            inner.GetAsync(key, token);
+
+        public void Refresh(string key) => inner.Refresh(key);
+
+        public Task RefreshAsync(
+            string key,
+            CancellationToken token = default) =>
+            inner.RefreshAsync(key, token);
+
+        public void Remove(string key) => inner.Remove(key);
+
+        public Task RemoveAsync(
+            string key,
+            CancellationToken token = default) =>
+            inner.RemoveAsync(key, token);
+
+        public void Set(
+            string key,
+            byte[] value,
+            DistributedCacheEntryOptions options) =>
+            inner.Set(key, value, options);
+
+        public Task SetAsync(
+            string key,
+            byte[] value,
+            DistributedCacheEntryOptions options,
+            CancellationToken token = default) =>
+            inner.SetAsync(key, value, options, token);
+    }
+}

tests/Jiaowu.Api.Tests/ApprovalsControllerTests.cs

@@ -0,0 +1,301 @@
+using Jiaowu.Api.Controllers;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Tests;
+
+public sealed class ApprovalsControllerTests
+{
+    [Fact]
+    public async Task MyCourses_IncludesPublishedScheduledTaskAfterCurrentTermChanges()
+    {
+        await using var fixture = await ApprovalFixture.CreateAsync();
+        fixture.CurrentTerm.IsCurrent = false;
+        fixture.Db.AcademicTerms.Add(new AcademicTerm
+        {
+            Code = "2026-2",
+            Name = "2026—2027 学年第二学期",
+            AcademicYear = "2026-2027",
+            Season = TermSeason.Spring,
+            StartDate = new DateOnly(2027, 2, 20),
+            EndDate = new DateOnly(2027, 7, 1),
+            IsCurrent = true
+        });
+        fixture.Db.SchedulePlans.Add(new SchedulePlan
+        {
+            AcademicTermId = fixture.CurrentTerm.Id,
+            Name = "正式课表",
+            Version = "v1",
+            Status = SchedulePlanStatus.Published,
+            Entries =
+            [
+                new ScheduleEntry
+                {
+                    TeachingTaskId = fixture.CurrentTask.Id,
+                    DayOfWeek = 1,
+                    StartPeriod = 1,
+                    PeriodCount = 2,
+                    StartWeek = 1,
+                    EndWeek = 16,
+                    WeekPattern = WeekPattern.All
+                }
+            ]
+        });
+        await fixture.Db.SaveChangesAsync();
+
+        var result = await fixture.Controller.GetMyEnrolledCourses(
+            CancellationToken.None);
+
+        var ok = Assert.IsType<OkObjectResult>(result);
+        var options = Assert.IsAssignableFrom<
+            IEnumerable<StudentApprovalCourseOption>>(ok.Value).ToList();
+        var option = Assert.Single(options);
+        Assert.Equal(fixture.CurrentTask.Id, option.TeachingTaskId);
+        Assert.Equal(fixture.CurrentCourse.Id, option.CourseId);
+        Assert.True(option.HasPublishedSchedule);
+    }
+
+    [Fact]
+    public async Task Exemption_RejectsTeachingTaskOutsideStudentsCurrentCourses()
+    {
+        await using var fixture = await ApprovalFixture.CreateAsync();
+        var unrelatedTask = new TeachingTask
+        {
+            TaskNumber = "2026-1-OTHER-01",
+            Name = "其他教学班",
+            AcademicTermId = fixture.CurrentTerm.Id,
+            CourseId = fixture.SubstituteCourse.Id,
+            Capacity = 30,
+            Status = TeachingTaskStatus.Published
+        };
+        fixture.Db.TeachingTasks.Add(unrelatedTask);
+        await fixture.Db.SaveChangesAsync();
+
+        var result = await fixture.Controller.ApplyExemption(
+            new ExemptionRequest(unrelatedTask.Id, "申请原因"),
+            CancellationToken.None);
+
+        Assert.IsType<ConflictObjectResult>(result);
+        Assert.Empty(fixture.Db.CourseExemptions);
+    }
+
+    [Fact]
+    public async Task Substitution_AcceptsCurrentCourseAndPublishedPassedCourse()
+    {
+        await using var fixture = await ApprovalFixture.CreateAsync();
+        var historicalTerm = new AcademicTerm
+        {
+            Code = "2025-2",
+            Name = "2025—2026 学年第二学期",
+            AcademicYear = "2025-2026",
+            Season = TermSeason.Spring,
+            StartDate = new DateOnly(2026, 2, 20),
+            EndDate = new DateOnly(2026, 7, 1)
+        };
+        var historicalTask = new TeachingTask
+        {
+            TaskNumber = "2025-2-PASS-01",
+            Name = "已通过课程教学班",
+            AcademicTermId = historicalTerm.Id,
+            CourseId = fixture.SubstituteCourse.Id,
+            Capacity = 30,
+            Status = TeachingTaskStatus.Closed
+        };
+        var sheet = new GradeSheet
+        {
+            TeachingTaskId = historicalTask.Id,
+            Status = GradeSheetStatus.Published,
+            PublishedAt = DateTime.UtcNow.AddDays(-30),
+            Records =
+            [
+                new GradeRecord
+                {
+                    StudentId = fixture.Student.Id,
+                    TotalScore = 86,
+                    GradePoint = 3.6m
+                }
+            ]
+        };
+        fixture.Db.AddRange(historicalTerm, historicalTask, sheet);
+        await fixture.Db.SaveChangesAsync();
+
+        var result = await fixture.Controller.ApplySubstitution(
+            new SubstitutionRequest(
+                fixture.CurrentCourse.Id,
+                fixture.SubstituteCourse.Id,
+                "课程内容相近"),
+            CancellationToken.None);
+
+        Assert.IsType<CreatedResult>(result);
+        var substitution = Assert.Single(fixture.Db.CourseSubstitutions);
+        Assert.Equal(fixture.CurrentCourse.Id, substitution.OriginalCourseId);
+        Assert.Equal(
+            fixture.SubstituteCourse.Id,
+            substitution.SubstituteCourseId);
+    }
+
+    private sealed class ApprovalFixture : IAsyncDisposable
+    {
+        private ApprovalFixture(
+            SqliteConnection connection,
+            AppDbContext db,
+            Student student,
+            AcademicTerm currentTerm,
+            Course currentCourse,
+            Course substituteCourse,
+            TeachingTask currentTask,
+            ApprovalsController controller)
+        {
+            Connection = connection;
+            Db = db;
+            Student = student;
+            CurrentTerm = currentTerm;
+            CurrentCourse = currentCourse;
+            SubstituteCourse = substituteCourse;
+            CurrentTask = currentTask;
+            Controller = controller;
+        }
+
+        private SqliteConnection Connection { get; }
+        public AppDbContext Db { get; }
+        public Student Student { get; }
+        public AcademicTerm CurrentTerm { get; }
+        public Course CurrentCourse { get; }
+        public Course SubstituteCourse { get; }
+        public TeachingTask CurrentTask { get; }
+        public ApprovalsController Controller { get; }
+
+        public static async Task<ApprovalFixture> CreateAsync()
+        {
+            var connection = new SqliteConnection("Data Source=:memory:");
+            await connection.OpenAsync();
+            var options = new DbContextOptionsBuilder<AppDbContext>()
+                .UseSqlite(connection)
+                .Options;
+            var db = new AppDbContext(options);
+            await db.Database.EnsureCreatedAsync();
+
+            var college = new College { Code = "CS", Name = "计算机学院" };
+            var major = new Major
+            {
+                Code = "080901",
+                Name = "计算机科学与技术",
+                CollegeId = college.Id,
+                DegreeType = "工学学士"
+            };
+            var administrativeClass = new AdministrativeClass
+            {
+                Code = "CS2026-01",
+                Name = "计科 2026-1 班",
+                MajorId = major.Id,
+                Grade = 2026
+            };
+            var user = new ApplicationUser
+            {
+                Id = Guid.NewGuid(),
+                UserName = "202601001",
+                NormalizedUserName = "202601001",
+                DisplayName = "测试学生"
+            };
+            var student = new Student
+            {
+                StudentNumber = "202601001",
+                Name = "测试学生",
+                UserId = user.Id,
+                AdministrativeClassId = administrativeClass.Id,
+                EnrollmentYear = 2026,
+                EnrollmentDate = new DateOnly(2026, 9, 1)
+            };
+            var currentTerm = new AcademicTerm
+            {
+                Code = "2026-1",
+                Name = "2026—2027 学年第一学期",
+                AcademicYear = "2026-2027",
+                Season = TermSeason.Autumn,
+                StartDate = new DateOnly(2026, 9, 1),
+                EndDate = new DateOnly(2027, 1, 20),
+                IsCurrent = true
+            };
+            var currentCourse = CreateCourse(college.Id, "CS101", "程序设计基础");
+            var substituteCourse = CreateCourse(college.Id, "CS102", "程序设计进阶");
+            var currentTask = new TeachingTask
+            {
+                TaskNumber = "2026-1-CS101-01",
+                Name = "程序设计基础教学班",
+                AcademicTermId = currentTerm.Id,
+                CourseId = currentCourse.Id,
+                Capacity = 60,
+                Status = TeachingTaskStatus.Published,
+                Classes =
+                [
+                    new TeachingTaskClass
+                    {
+                        AdministrativeClassId = administrativeClass.Id
+                    }
+                ]
+            };
+            db.AddRange(
+                college,
+                major,
+                administrativeClass,
+                user,
+                student,
+                currentTerm,
+                currentCourse,
+                substituteCourse,
+                currentTask);
+            await db.SaveChangesAsync();
+
+            var controller = new ApprovalsController(
+                db,
+                new StudentDataScope(user.Id));
+            return new ApprovalFixture(
+                connection,
+                db,
+                student,
+                currentTerm,
+                currentCourse,
+                substituteCourse,
+                currentTask,
+                controller);
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await Db.DisposeAsync();
+            await Connection.DisposeAsync();
+        }
+
+        private static Course CreateCourse(
+            Guid collegeId,
+            string code,
+            string name) =>
+            new()
+            {
+                Code = code,
+                Name = name,
+                CollegeId = collegeId,
+                Credits = 3,
+                TotalHours = 48,
+                LectureHours = 32,
+                PracticeHours = 16,
+                Nature = CourseNature.MajorRequired,
+                AssessmentMethod = AssessmentMethod.Examination
+            };
+    }
+
+    private sealed class StudentDataScope(Guid userId) : ICurrentUserDataScope
+    {
+        public CurrentUserScope Current { get; } = new(
+            userId,
+            "测试学生",
+            null,
+            DataScope.Self,
+            new HashSet<string>([SystemRoles.Student]));
+    }
+}

tests/Jiaowu.Api.Tests/AuthControllerTests.cs

@@ -2,6 +2,7 @@ using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Mvc;
@@ -103,7 +104,11 @@ public sealed class AuthControllerTests
         var userManager = scope.ServiceProvider
             .GetRequiredService<UserManager<ApplicationUser>>();
         Assert.True(db.Database.CreateExecutionStrategy().RetriesOnFailure);
-        var controller = new AuthController(db, userManager, new StubTokenService());
+        var controller = new AuthController(
+            db,
+            userManager,
+            new StubTokenService(),
+            NoOpAppCache.Instance);
         var request = new StudentActivationRequest(
             student.Name,
             student.StudentNumber,

tests/Jiaowu.Api.Tests/BaseDataControllerTests.cs

@@ -1,5 +1,6 @@
 using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.Sqlite;
@@ -21,7 +22,7 @@ public sealed class BaseDataControllerTests : IAsyncDisposable
             .Options;
         db = new AppDbContext(options);
         db.Database.EnsureCreated();
-        controller = new BaseDataController(db);
+        controller = new BaseDataController(db, NoOpAppCache.Instance);
     }
 
     [Fact]

tests/Jiaowu.Api.Tests/PersonnelControllerTests.cs

@@ -2,6 +2,7 @@ using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.AspNetCore.Mvc;
@@ -61,7 +62,8 @@ public sealed class PersonnelControllerTests
         var controller = new PersonnelController(
             db,
             new TestDataScope(college.Id),
-            userManager);
+            userManager,
+            NoOpAppCache.Instance);
 
         var result = await controller.ActivateTeacherAccount(
             teacher.Id,

tests/Jiaowu.Api.Tests/SchedulePublishJobProcessorTests.cs

@@ -1,4 +1,5 @@
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Scheduling;
 using Microsoft.EntityFrameworkCore;
@@ -47,6 +48,7 @@ public sealed class SchedulePublishJobProcessorTests
                 $"Data Source={databasePath};Pooling=False"));
         services.AddScoped<SchedulePlanPublisher>();
         services.AddScoped<SchedulePublishJobProcessor>();
+        services.AddSingleton<IAppCache>(NoOpAppCache.Instance);
         var provider = services.BuildServiceProvider();
 
         try

tests/Jiaowu.Api.Tests/ScheduleSettingsControllerTests.cs

@@ -1,9 +1,13 @@
 using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.Sqlite;
 using Microsoft.EntityFrameworkCore;
+using System.Collections;
+using System.Text.Encodings.Web;
+using System.Text.Json;
 
 namespace Jiaowu.Api.Tests;
 
@@ -67,7 +71,7 @@ public sealed class ScheduleSettingsControllerTests
             secondTask);
         await db.SaveChangesAsync();
 
-        var controller = new ScheduleSettingsController(db);
+        var controller = new ScheduleSettingsController(db, NoOpAppCache.Instance);
         var result = await controller.SaveConstraintsBatch(
             new TeachingTaskScheduleConstraintBatchRequest(
                 term.Id,
@@ -102,6 +106,212 @@ public sealed class ScheduleSettingsControllerTests
         });
     }
 
+    [Fact]
+    public async Task Get_constraints_materializes_teachers_and_allowed_classrooms()
+    {
+        await using var connection = new SqliteConnection("Data Source=:memory:");
+        await connection.OpenAsync();
+        var options = new DbContextOptionsBuilder<AppDbContext>()
+            .UseSqlite(connection)
+            .Options;
+        await using var db = new AppDbContext(options);
+        await db.Database.EnsureCreatedAsync();
+
+        var college = new College { Code = "CS", Name = "计算机学院" };
+        var course = new Course
+        {
+            Code = "CS101",
+            Name = "程序设计基础",
+            College = college,
+            Credits = 4,
+            TotalHours = 64,
+            LectureHours = 48,
+            PracticeHours = 16
+        };
+        var term = new AcademicTerm
+        {
+            Code = "2026-F",
+            Name = "2026 秋季",
+            AcademicYear = "2026-2027",
+            Season = TermSeason.Autumn,
+            StartDate = new DateOnly(2026, 9, 7),
+            EndDate = new DateOnly(2027, 1, 17)
+        };
+        var teacher = new Teacher
+        {
+            TeacherNumber = "T001",
+            Name = "测试教师",
+            College = college
+        };
+        var classroom = new Classroom
+        {
+            Code = "J1-201",
+            Name = "J1-201",
+            Capacity = 80,
+            Building = new Building
+            {
+                Code = "J1",
+                Name = "第一教学楼",
+                Campus = new Campus { Code = "MAIN", Name = "主校区" }
+            }
+        };
+        var task = NewTask("TASK-01", course, term);
+        task.Teachers.Add(new TeachingTaskTeacher
+        {
+            Teacher = teacher,
+            IsPrimary = true
+        });
+        var constraint = new TeachingTaskScheduleConstraint
+        {
+            TeachingTask = task,
+            AllowedDayOfWeeks = "1,3,5",
+            EarliestPeriod = 1,
+            LatestPeriod = 8,
+            AllowedClassrooms =
+            [
+                new TeachingTaskAllowedClassroom { Classroom = classroom }
+            ]
+        };
+        db.AddRange(college, course, term, teacher, classroom, task, constraint);
+        await db.SaveChangesAsync();
+
+        var result = await new ScheduleSettingsController(db, NoOpAppCache.Instance)
+            .GetConstraints(term.Id, CancellationToken.None);
+
+        var ok = Assert.IsType<OkObjectResult>(result);
+        var payload = Assert.IsAssignableFrom<IEnumerable>(ok.Value);
+        Assert.Single(payload.Cast<object>());
+        var json = JsonSerializer.Serialize(
+            ok.Value,
+            new JsonSerializerOptions
+            {
+                Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
+            });
+        Assert.Contains("测试教师", json);
+        Assert.Contains(classroom.Id.ToString(), json);
+    }
+
+    [Fact]
+    public async Task MySql_schedule_settings_materialize_time_slots_and_constraints()
+    {
+        var connectionString =
+            Environment.GetEnvironmentVariable("JIAOWU_TEST_MYSQL_CONNECTION");
+        if (string.IsNullOrWhiteSpace(connectionString))
+            return;
+
+        var previousConnectionString =
+            Environment.GetEnvironmentVariable("ConnectionStrings__MySql");
+        AppDbContext db;
+        try
+        {
+            Environment.SetEnvironmentVariable(
+                "ConnectionStrings__MySql",
+                connectionString);
+            db = new AppDbContextFactory().CreateDbContext([]);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable(
+                "ConnectionStrings__MySql",
+                previousConnectionString);
+        }
+        await using var ownedDb = db;
+        var term = await db.AcademicTerms.FirstAsync();
+        var course = await db.Courses.FirstAsync();
+        var teacher = await db.Teachers.FirstAsync(
+            item => item.CollegeId == course.CollegeId);
+        var classroom = await db.Classrooms.FirstAsync();
+        await using var transaction = await db.Database.BeginTransactionAsync();
+        var periodNumber = await db.ScheduleTimeSlots
+            .Where(item => item.AcademicTermId == term.Id)
+            .Select(item => (int?)item.PeriodNumber)
+            .MaxAsync() ?? 0;
+
+        var task = new TeachingTask
+        {
+            TaskNumber = $"MYSQL-{Guid.NewGuid():N}"[..22],
+            Name = "MySQL 排课约束回归",
+            AcademicTermId = term.Id,
+            CourseId = course.Id,
+            Capacity = 60,
+            WeeklyHours = 2,
+            StartWeek = 1,
+            EndWeek = 16,
+            Status = TeachingTaskStatus.Published,
+            Teachers =
+            [
+                new TeachingTaskTeacher
+                {
+                    TeacherId = teacher.Id,
+                    IsPrimary = true
+                }
+            ]
+        };
+        db.Add(task);
+        db.Add(new ScheduleTimeSlot
+        {
+            AcademicTermId = term.Id,
+            PeriodNumber = periodNumber + 1,
+            Name = "MySQL 回归节次",
+            StartsAt = new TimeOnly(8, 0),
+            EndsAt = new TimeOnly(8, 45)
+        });
+        db.Add(new TeachingTaskScheduleConstraint
+        {
+            TeachingTask = task,
+            AllowedDayOfWeeks = "1,3,5",
+            EarliestPeriod = 1,
+            LatestPeriod = 8,
+            AllowedClassrooms =
+            [
+                new TeachingTaskAllowedClassroom { ClassroomId = classroom.Id }
+            ]
+        });
+        await db.SaveChangesAsync();
+        db.ChangeTracker.Clear();
+
+        var result = await new ScheduleSettingsController(db, NoOpAppCache.Instance)
+            .GetConstraints(term.Id, CancellationToken.None);
+
+        var ok = Assert.IsType<OkObjectResult>(result);
+        var payload = Assert.IsAssignableFrom<IEnumerable>(ok.Value);
+        Assert.Contains(payload.Cast<object>(), item =>
+            JsonSerializer.Serialize(item).Contains(task.TaskNumber));
+        var timeSlotsResult = await new ScheduleSettingsController(
+                db,
+                NoOpAppCache.Instance)
+            .GetTimeSlots(term.Id, CancellationToken.None);
+        var timeSlotsOk = Assert.IsType<OkObjectResult>(timeSlotsResult);
+        var timeSlotsJson = JsonSerializer.Serialize(timeSlotsOk.Value);
+        Assert.Contains("08:00", timeSlotsJson);
+
+        var examTimeSlotsResult = await new ExamsController(
+                db,
+                null!,
+                null!,
+                NoOpAppCache.Instance)
+            .GetTimeSlotsForTerm(term.Id, CancellationToken.None);
+        var examTimeSlotsOk =
+            Assert.IsType<OkObjectResult>(examTimeSlotsResult);
+        Assert.Contains(
+            "08:00",
+            JsonSerializer.Serialize(examTimeSlotsOk.Value));
+
+        var makeupTimeSlotsResult = await new MakeupExamsController(
+                db,
+                null!,
+                null!,
+                null!,
+                null!)
+            .GetTimeSlotsForTerm(term.Id, CancellationToken.None);
+        var makeupTimeSlotsOk =
+            Assert.IsType<OkObjectResult>(makeupTimeSlotsResult);
+        Assert.Contains(
+            "08:00",
+            JsonSerializer.Serialize(makeupTimeSlotsOk.Value));
+        await transaction.RollbackAsync();
+    }
+
     private static TeachingTask NewTask(
         string taskNumber,
         Course course,

tests/Jiaowu.Api.Tests/StatisticsControllerTests.cs

@@ -0,0 +1,150 @@
+using System.Text.Json;
+using ClosedXML.Excel;
+using Jiaowu.Api.Controllers;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Tests;
+
+public sealed class StatisticsControllerTests
+{
+    [Fact]
+    public async Task Course_summary_cache_is_scope_isolated_and_export_is_fresh()
+    {
+        await using var connection = new SqliteConnection("Data Source=:memory:");
+        await connection.OpenAsync();
+        var options = new DbContextOptionsBuilder<AppDbContext>()
+            .UseSqlite(connection)
+            .Options;
+        await using var db = new AppDbContext(options);
+        await db.Database.EnsureCreatedAsync();
+
+        var firstCollege = new College { Code = "C01", Name = "第一学院" };
+        var secondCollege = new College { Code = "C02", Name = "第二学院" };
+        var category = new CourseCategory { Code = "CAT", Name = "测试分类" };
+        db.AddRange(
+            firstCollege,
+            secondCollege,
+            category,
+            CreateCourse("C001", firstCollege, category),
+            CreateCourse("C002", secondCollege, category));
+        await db.SaveChangesAsync();
+
+        var cache = new RecordingCache();
+        var firstController = new StatisticsController(
+            db,
+            new CollegeDataScope(firstCollege.Id),
+            cache);
+        var secondController = new StatisticsController(
+            db,
+            new CollegeDataScope(secondCollege.Id),
+            cache);
+
+        var first = await firstController.GetCourseSummary(
+            null,
+            null,
+            null,
+            CancellationToken.None);
+        Assert.Equal(1, TotalCourses(first));
+
+        db.Courses.Add(CreateCourse("C003", firstCollege, category));
+        await db.SaveChangesAsync();
+
+        var cached = await firstController.GetCourseSummary(
+            null,
+            null,
+            null,
+            CancellationToken.None);
+        Assert.Equal(1, TotalCourses(cached));
+
+        var otherCollege = await secondController.GetCourseSummary(
+            null,
+            null,
+            null,
+            CancellationToken.None);
+        Assert.Equal(1, TotalCourses(otherCollege));
+        Assert.Equal(2, cache.SourceCalls);
+        Assert.Equal(2, cache.Keys.Count);
+
+        var export = await firstController.ExportCourses(
+            null,
+            null,
+            null,
+            CancellationToken.None);
+        var file = Assert.IsType<FileContentResult>(export);
+        using var stream = new MemoryStream(file.FileContents);
+        using var workbook = new XLWorkbook(stream);
+        Assert.Equal(
+            2,
+            workbook.Worksheet("课程性质").Cell(1, 2).GetValue<int>());
+        Assert.Equal(2, cache.SourceCalls);
+    }
+
+    private static int TotalCourses(ActionResult<object> result)
+    {
+        var json = Assert.IsType<JsonElement>(result.Value);
+        return json.GetProperty("totals").GetProperty("totalCourses").GetInt32();
+    }
+
+    private static Course CreateCourse(
+        string code,
+        College college,
+        CourseCategory category) =>
+        new()
+        {
+            Code = code,
+            Name = $"课程 {code}",
+            CollegeId = college.Id,
+            CourseCategoryId = category.Id,
+            Nature = CourseNature.MajorRequired,
+            Credits = 2,
+            TotalHours = 32,
+            LectureHours = 32,
+            AssessmentMethod = AssessmentMethod.Examination
+        };
+
+    private sealed class RecordingCache : IAppCache
+    {
+        private readonly Dictionary<string, object> values = [];
+
+        public int SourceCalls { get; private set; }
+        public IReadOnlyCollection<string> Keys => values.Keys;
+
+        public async Task<T> GetOrCreateAsync<T>(
+            string key,
+            Func<CancellationToken, Task<T>> factory,
+            AppCacheProfile profile,
+            IReadOnlyCollection<string> tags,
+            CancellationToken cancellationToken)
+        {
+            if (values.TryGetValue(key, out var value))
+                return (T)value;
+
+            SourceCalls++;
+            var loaded = await factory(cancellationToken);
+            values[key] = loaded!;
+            return loaded;
+        }
+
+        public ValueTask RemoveByTagAsync(
+            string tag,
+            CancellationToken cancellationToken = default) =>
+            ValueTask.CompletedTask;
+    }
+
+    private sealed class CollegeDataScope(Guid collegeId) : ICurrentUserDataScope
+    {
+        public CurrentUserScope Current { get; } = new(
+            Guid.NewGuid(),
+            "学院管理员",
+            collegeId,
+            DataScope.College,
+            new HashSet<string> { SystemRoles.CollegeAdmin });
+    }
+}

tests/Jiaowu.Api.Tests/TeachingTasksControllerTests.cs

@@ -2,6 +2,7 @@ using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.Sqlite;
@@ -146,7 +147,8 @@ public sealed class TeachingTasksControllerTests
             this.course = course;
             Controller = new TeachingTasksController(
                 db,
-                dataScope);
+                dataScope,
+                NoOpAppCache.Instance);
         }
 
         public AppDbContext Db { get; }

web/src/views/ApprovalCenterView.vue

@@ -1,9 +1,53 @@
 <script setup lang="ts">
 import { computed, onMounted, reactive, ref } from 'vue'
-import { Check, Close, Plus, Refresh } from '@element-plus/icons-vue'
+import {
+  Check,
+  Clock,
+  Close,
+  DocumentChecked,
+  Plus,
+  Refresh,
+  Search,
+  Switch,
+} from '@element-plus/icons-vue'
 import http, { apiErrorMessage } from '../api/http'
 import { useAuthStore } from '../stores/auth'
 
+interface CourseOption {
+  teachingTaskId: string
+  courseId: string
+  taskNumber: string
+  courseCode: string
+  courseName: string
+  credits: number
+  academicTermName: string
+  teacherNames: string[]
+  hasPublishedSchedule: boolean
+  schedulingMode: 'Standard' | 'Flexible'
+}
+
+interface GradeOption {
+  courseId: string
+  courseCode: string
+  courseName: string
+  credits: number
+  totalScore: number | null
+  gradePoint: number | null
+  examStatus: string
+  academicTermName: string
+  taskNumber: string
+  publishedAt: string | null
+}
+
+interface SubstitutionTarget {
+  courseId: string
+  courseCode: string
+  courseName: string
+  credits: number
+  source: 'assigned' | 'failed'
+  detail: string
+}
+
 const auth = useAuthStore()
 const isManager = computed(() => auth.user?.roles.some(r => ['SuperAdmin', 'AcademicAdmin', 'CollegeAdmin'].includes(r)) ?? false)
 const isTeacher = computed(() => auth.user?.roles.includes('Teacher') && !isManager.value)
@@ -11,79 +55,259 @@ const isStudent = computed(() => auth.user?.roles.includes('Student') && !isMana
 
 const pending = ref<any[]>([])
 const loading = ref(false)
+const submitting = ref(false)
 const tab = ref(isManager.value ? 'pending' : 'mine')
 const dialog = ref(false)
 const dialogType = ref('')
+const courseKeyword = ref('')
+const originalKeyword = ref('')
+const substituteKeyword = ref('')
 const rejectDialog = ref(false)
 const rejectItem = ref<any>(null)
 const rejectComment = ref('')
 
-const enrolledCourses = ref<any[]>([])
+const enrolledCourses = ref<CourseOption[]>([])
 const gradeRecords = ref<any[]>([])
-const myGrades = ref<any[]>([])
+const myGrades = ref<GradeOption[]>([])
 const myExemptions = ref<any[]>([])
 const myDeferred = ref<any[]>([])
+const mySubstitutions = ref<any[]>([])
 
-const form = reactive({ teachingTaskId: '', reason: '', originalCourseId: '', substituteCourseId: '', gradeRecordId: '', requestedScore: 0 })
+const form = reactive({
+  teachingTaskId: '',
+  reason: '',
+  originalCourseId: '',
+  substituteCourseId: '',
+  gradeRecordId: '',
+  requestedScore: 0,
+})
+
+const dialogTitle = computed(() => ({
+  exemption: '发起免修申请',
+  deferred: '发起缓考申请',
+  gradeMod: '成绩修改申请',
+  substitution: '发起课程替代申请',
+}[dialogType.value] ?? '发起申请'))
+
+const selectedCourse = computed(() =>
+  enrolledCourses.value.find(course => course.teachingTaskId === form.teachingTaskId))
+
+const filteredCourses = computed(() => {
+  const keyword = courseKeyword.value.trim().toLocaleLowerCase()
+  if (!keyword) return enrolledCourses.value
+  return enrolledCourses.value.filter(course =>
+    [course.courseCode, course.courseName, course.taskNumber, ...course.teacherNames]
+      .some(value => value?.toLocaleLowerCase().includes(keyword)))
+})
+
+function uniqueGrades(predicate: (grade: GradeOption) => boolean) {
+  const result = new Map<string, GradeOption>()
+  for (const grade of myGrades.value) {
+    if (predicate(grade) && !result.has(grade.courseId)) result.set(grade.courseId, grade)
+  }
+  return [...result.values()]
+}
+
+const failedGrades = computed(() =>
+  uniqueGrades(grade => grade.totalScore != null && Number(grade.totalScore) < 60))
+const passedGrades = computed(() =>
+  uniqueGrades(grade => grade.totalScore != null && Number(grade.totalScore) >= 60))
+
+const substitutionTargets = computed<SubstitutionTarget[]>(() => {
+  const result = new Map<string, SubstitutionTarget>()
+  for (const course of enrolledCourses.value) {
+    result.set(course.courseId, {
+      courseId: course.courseId,
+      courseCode: course.courseCode,
+      courseName: course.courseName,
+      credits: course.credits,
+      source: 'assigned',
+      detail: `${course.academicTermName} · ${course.taskNumber}`,
+    })
+  }
+  for (const grade of failedGrades.value) {
+    if (!result.has(grade.courseId)) {
+      result.set(grade.courseId, {
+        courseId: grade.courseId,
+        courseCode: grade.courseCode,
+        courseName: grade.courseName,
+        credits: grade.credits,
+        source: 'failed',
+        detail: `${grade.academicTermName} · ${grade.totalScore} 分`,
+      })
+    }
+  }
+  return [...result.values()]
+})
+
+function matchesCourse(item: { courseCode: string; courseName: string }, keyword: string) {
+  const normalized = keyword.trim().toLocaleLowerCase()
+  return !normalized ||
+    item.courseCode.toLocaleLowerCase().includes(normalized) ||
+    item.courseName.toLocaleLowerCase().includes(normalized)
+}
+
+function selectOriginal(courseId: string) {
+  form.originalCourseId = courseId
+  if (form.substituteCourseId === courseId) form.substituteCourseId = ''
+}
+
+const filteredOriginalCourses = computed(() =>
+  substitutionTargets.value.filter(item => matchesCourse(item, originalKeyword.value)))
+const filteredSubstituteCourses = computed(() =>
+  passedGrades.value.filter(item => matchesCourse(item, substituteKeyword.value)))
+
+const selectedOriginal = computed(() =>
+  substitutionTargets.value.find(item => item.courseId === form.originalCourseId))
+const selectedSubstitute = computed(() =>
+  passedGrades.value.find(item => item.courseId === form.substituteCourseId))
+
+const recordCount = computed(() =>
+  myExemptions.value.length + myDeferred.value.length + mySubstitutions.value.length)
 
 async function load() {
   loading.value = true
   try {
     if (isManager.value) pending.value = (await http.get('/approvals/pending')).data
     if (isStudent.value) {
-      const [courses, grades, ex, df] = await Promise.all([
-        http.get('/approvals/my-courses'), http.get('/approvals/my-grades'),
-        http.get('/approvals/exemptions/mine'), http.get('/approvals/deferred/mine'),
+      const [courses, grades, ex, df, substitutions] = await Promise.all([
+        http.get('/approvals/my-courses'),
+        http.get('/approvals/my-grades'),
+        http.get('/approvals/exemptions/mine'),
+        http.get('/approvals/deferred/mine'),
+        http.get('/approvals/substitutions/mine'),
       ])
-      enrolledCourses.value = courses.data; myGrades.value = grades.data
-      myExemptions.value = ex.data; myDeferred.value = df.data
+      enrolledCourses.value = courses.data
+      myGrades.value = grades.data
+      myExemptions.value = ex.data
+      myDeferred.value = df.data
+      mySubstitutions.value = substitutions.data
     }
     if (isTeacher.value) gradeRecords.value = (await http.get('/approvals/grade-records')).data
-  } catch (e) { ElMessage.error(apiErrorMessage(e)) }
-  finally { loading.value = false }
+  } catch (e) {
+    ElMessage.error(apiErrorMessage(e))
+  } finally {
+    loading.value = false
+  }
 }
 
 function openDialog(type: string) {
   dialogType.value = type
-  Object.assign(form, { teachingTaskId: '', reason: '', originalCourseId: '', substituteCourseId: '', gradeRecordId: '', requestedScore: 0 })
+  courseKeyword.value = ''
+  originalKeyword.value = ''
+  substituteKeyword.value = ''
+  Object.assign(form, {
+    teachingTaskId: '',
+    reason: '',
+    originalCourseId: '',
+    substituteCourseId: '',
+    gradeRecordId: '',
+    requestedScore: 0,
+  })
   dialog.value = true
 }
 
 async function submitForm() {
-  if (!form.reason.trim()) { ElMessage.warning('请填写原因'); return }
+  if (!form.reason.trim()) {
+    ElMessage.warning('请填写申请原因')
+    return
+  }
+  submitting.value = true
   try {
     if (dialogType.value === 'exemption') {
-      if (!form.teachingTaskId) { ElMessage.warning('请选择课程'); return }
-      await http.post('/approvals/exemptions', { teachingTaskId: form.teachingTaskId, reason: form.reason })
-    } else if (dialogType.value === 'deferred') {
-      if (!form.teachingTaskId) { ElMessage.warning('请选择课程'); return }
-      await http.post('/approvals/deferred', { teachingTaskId: form.teachingTaskId, reason: form.reason })
-    } else if (dialogType.value === 'gradeMod') {
-      if (!form.gradeRecordId) { ElMessage.warning('请选择成绩记录'); return }
-      await http.post('/approvals/grade-modifications', { gradeRecordId: form.gradeRecordId, requestedScore: form.requestedScore, reason: form.reason })
-    } else if (dialogType.value === 'substitution') {
-      if (!form.originalCourseId || !form.substituteCourseId) { ElMessage.warning('请选择两门课程'); return }
-      await http.post('/approvals/substitutions', { originalCourseId: form.originalCourseId, substituteCourseId: form.substituteCourseId, reason: form.reason })
+      if (!form.teachingTaskId) {
+        ElMessage.warning('请选择申请免修的课程')
+        return
+      }
+      await http.post('/approvals/exemptions', {
+        teachingTaskId: form.teachingTaskId,
+        reason: form.reason,
+      })
+    } else if (dialogType.value === 'deferred') {
+      if (!form.teachingTaskId) {
+        ElMessage.warning('请选择申请缓考的课程')
+        return
+      }
+      await http.post('/approvals/deferred', {
+        teachingTaskId: form.teachingTaskId,
+        reason: form.reason,
+      })
+    } else if (dialogType.value === 'gradeMod') {
+      if (!form.gradeRecordId) {
+        ElMessage.warning('请选择成绩记录')
+        return
+      }
+      await http.post('/approvals/grade-modifications', {
+        gradeRecordId: form.gradeRecordId,
+        requestedScore: form.requestedScore,
+        reason: form.reason,
+      })
+    } else if (dialogType.value === 'substitution') {
+      if (!form.originalCourseId || !form.substituteCourseId) {
+        ElMessage.warning('请完整选择被替代课程和替代课程')
+        return
+      }
+      await http.post('/approvals/substitutions', {
+        originalCourseId: form.originalCourseId,
+        substituteCourseId: form.substituteCourseId,
+        reason: form.reason,
+      })
+    }
+    dialog.value = false
+    ElMessage.success('申请已提交')
+    await load()
+  } catch (e) {
+    ElMessage.error(apiErrorMessage(e))
+  } finally {
+    submitting.value = false
   }
-    dialog.value = false; ElMessage.success('申请已提交'); await load()
-  } catch (e) { ElMessage.error(apiErrorMessage(e)) }
 }
 
 async function approveItem(item: any) {
   try {
-    const ep = `/approvals/${item.type === 'CourseExemption' ? 'exemptions' : item.type === 'DeferredExam' ? 'deferred' : item.type === 'CourseSubstitution' ? 'substitutions' : ''}`;
-    if (ep) { await http.post(`${ep}/${item.id}/approve`); ElMessage.success('已通过'); await load() }
-  } catch (e) { ElMessage.error(apiErrorMessage(e)) }
+    const ep = `/approvals/${item.type === 'CourseExemption' ? 'exemptions' : item.type === 'DeferredExam' ? 'deferred' : item.type === 'CourseSubstitution' ? 'substitutions' : ''}`
+    if (ep) {
+      await http.post(`${ep}/${item.id}/approve`)
+      ElMessage.success('已通过')
+      await load()
+    }
+  } catch (e) {
+    ElMessage.error(apiErrorMessage(e))
+  }
 }
 
-function openReject(item: any) { rejectItem.value = item; rejectComment.value = ''; rejectDialog.value = true }
+function openReject(item: any) {
+  rejectItem.value = item
+  rejectComment.value = ''
+  rejectDialog.value = true
+}
 
 async function rejectSubmit() {
   if (!rejectItem.value) return
   try {
-    const ep = `/approvals/${rejectItem.value.type === 'CourseExemption' ? 'exemptions' : rejectItem.value.type === 'DeferredExam' ? 'deferred' : rejectItem.value.type === 'CourseSubstitution' ? 'substitutions' : ''}`;
-    if (ep) { await http.post(`${ep}/${rejectItem.value.id}/reject`, { comment: rejectComment.value }); rejectDialog.value = false; ElMessage.success('已驳回'); await load() }
-  } catch (e) { ElMessage.error(apiErrorMessage(e)) }
+    const ep = `/approvals/${rejectItem.value.type === 'CourseExemption' ? 'exemptions' : rejectItem.value.type === 'DeferredExam' ? 'deferred' : rejectItem.value.type === 'CourseSubstitution' ? 'substitutions' : ''}`
+    if (ep) {
+      await http.post(`${ep}/${rejectItem.value.id}/reject`, { comment: rejectComment.value })
+      rejectDialog.value = false
+      ElMessage.success('已驳回')
+      await load()
+    }
+  } catch (e) {
+    ElMessage.error(apiErrorMessage(e))
+  }
+}
+
+function statusText(status: string) {
+  return status === 'Submitted' ? '待审核' : status === 'Approved' ? '已通过' : '已驳回'
+}
+
+function statusType(status: string) {
+  return status === 'Approved' ? 'success' : status === 'Rejected' ? 'danger' : 'warning'
+}
+
+function courseScheduleText(course: CourseOption) {
+  if (course.schedulingMode === 'Flexible') return '非排时课程'
+  return course.hasPublishedSchedule ? '课表已发布' : '等待课表发布'
 }
 
 onMounted(load)
@@ -92,92 +316,419 @@ onMounted(load)
 <template>
   <div class="page-stack appr-page">
     <section class="page-intro">
-      <div><span class="section-kicker">APPROVAL CENTER</span><h2>审批中心</h2><p>学籍异动、调停课、成绩审核、考勤申诉、免修、缓考、成绩修改、课程替代。</p></div>
-      <div style="display:flex;gap:8px">
-        <el-button v-if="isStudent" :icon="Plus" @click="openDialog('exemption')">免修</el-button>
-        <el-button v-if="isStudent" :icon="Plus" @click="openDialog('deferred')">缓考</el-button>
-        <el-button v-if="isStudent" :icon="Plus" @click="openDialog('substitution')">课程替代</el-button>
-        <el-button v-if="isTeacher" :icon="Plus" type="primary" @click="openDialog('gradeMod')">成绩修改</el-button>
-        <el-button :icon="Refresh" @click="load">刷新</el-button>
+      <div>
+        <span class="section-kicker">APPROVAL CENTER</span>
+        <h2>审批中心</h2>
+        <p>{{ isStudent ? '从实际修读课程发起申请，查看审核进度与处理结果。' : '集中处理教务申请与审核任务。' }}</p>
       </div>
+      <el-button :icon="Refresh" @click="load">刷新</el-button>
     </section>
 
-    <el-segmented v-model="tab" :options="[
-      ...(isManager ? [{ label: `待审批 (${pending.length})`, value: 'pending' }] : []),
-      { label: '我的记录', value: 'mine' },
-    ]" style="margin-bottom:16px" />
+    <section v-if="isStudent" v-loading="loading" class="application-launcher">
+      <button class="launch-card exemption" type="button" @click="openDialog('exemption')">
+        <span class="launch-icon"><DocumentChecked /></span>
+        <span class="launch-copy">
+          <small>COURSE EXEMPTION</small>
+          <b>申请免修</b>
+          <em>从当前或已发布课表的修读课程中选择</em>
+        </span>
+        <span class="launch-meta">{{ enrolledCourses.length }} 门可选 <Plus /></span>
+      </button>
+      <button class="launch-card deferred" type="button" @click="openDialog('deferred')">
+        <span class="launch-icon"><Clock /></span>
+        <span class="launch-copy">
+          <small>DEFERRED EXAM</small>
+          <b>申请缓考</b>
+          <em>课程与教学班信息一并提交</em>
+        </span>
+        <span class="launch-meta">{{ enrolledCourses.length }} 门可选 <Plus /></span>
+      </button>
+      <button class="launch-card substitution" type="button" @click="openDialog('substitution')">
+        <span class="launch-icon"><Switch /></span>
+        <span class="launch-copy">
+          <small>COURSE SUBSTITUTION</small>
+          <b>申请课程替代</b>
+          <em>修读中或未通过课程 → 已通过课程</em>
+        </span>
+        <span class="launch-meta">{{ passedGrades.length }} 门可替代 <Plus /></span>
+      </button>
+    </section>
+
+    <div class="approval-tabs">
+      <el-segmented
+        v-model="tab"
+        :options="[
+          ...(isManager ? [{ label: `待审批 (${pending.length})`, value: 'pending' }] : []),
+          { label: `我的记录${isStudent ? ` (${recordCount})` : ''}`, value: 'mine' },
+        ]"
+      />
+      <el-button v-if="isTeacher" :icon="Plus" type="primary" @click="openDialog('gradeMod')">成绩修改</el-button>
+    </div>
 
-    <!-- Pending -->
     <section v-if="tab === 'pending'" v-loading="loading" class="appr-list">
       <article v-for="item in pending" :key="`${item.type}-${item.id}`" class="appr-card">
         <el-tag size="small" :type="item.label === '考勤申诉' ? 'warning' : 'primary'">{{ item.label }}</el-tag>
-        <div class="appr-body"><b>{{ item.title }}</b><p>{{ item.desc }}</p><small>{{ item.college }} · {{ new Date(item.time).toLocaleString('zh-CN') }}</small></div>
-        <div class="appr-actions" v-if="['CourseExemption','DeferredExam','CourseSubstitution'].includes(item.type)">
+        <div class="appr-body">
+          <b>{{ item.title }}</b>
+          <p>{{ item.desc }}</p>
+          <small>{{ item.college }} · {{ new Date(item.time).toLocaleString('zh-CN') }}</small>
+        </div>
+        <div v-if="['CourseExemption','DeferredExam','CourseSubstitution'].includes(item.type)" class="appr-actions">
           <el-button size="small" type="danger" plain :icon="Close" @click="openReject(item)">驳回</el-button>
           <el-button size="small" type="success" :icon="Check" @click="approveItem(item)">通过</el-button>
         </div>
-        <div class="appr-actions" v-else><el-button size="small" text type="primary" @click="$router.push(item.type==='StudentStatusChange'?'/student-status-changes':item.type==='CourseAdjustment'?'/course-adjustments':item.type==='GradeSheet'?'/grades':'/teacher-attendance')">查看 →</el-button></div>
+        <div v-else class="appr-actions">
+          <el-button
+            size="small"
+            text
+            type="primary"
+            @click="$router.push(item.type==='StudentStatusChange'?'/student-status-changes':item.type==='CourseAdjustment'?'/course-adjustments':item.type==='GradeSheet'?'/grades':'/teacher-attendance')"
+          >
+            查看 →
+          </el-button>
+        </div>
       </article>
       <el-empty v-if="!pending.length" description="暂无待审批" />
     </section>
 
-    <!-- My records -->
     <section v-if="tab === 'mine'" v-loading="loading">
       <template v-if="isStudent">
-        <h4 style="margin-bottom:8px">免修申请</h4>
-        <div class="appr-list" style="margin-bottom:16px">
-          <article v-for="e in myExemptions" :key="e.id" class="appr-card"><el-tag size="small" :type="e.status === 'Approved' ? 'success' : e.status === 'Rejected' ? 'danger' : 'warning'">{{ e.status === 'Submitted' ? '待审核' : e.status === 'Approved' ? '已通过' : '已驳回' }}</el-tag><div class="appr-body"><b>{{ e.courseName }}</b><p>{{ e.reason }}</p><small v-if="e.reviewComment">{{ e.reviewComment }}</small></div></article>
-          <el-empty v-if="!myExemptions.length" description="无" />
+        <div v-if="recordCount" class="record-columns">
+          <section class="record-group">
+            <header><span class="record-mark exemption"></span><b>免修申请</b><em>{{ myExemptions.length }}</em></header>
+            <div class="appr-list">
+              <article v-for="item in myExemptions" :key="item.id" class="appr-card compact">
+                <el-tag size="small" :type="statusType(item.status)">{{ statusText(item.status) }}</el-tag>
+                <div class="appr-body">
+                  <b>{{ item.courseName }}</b>
+                  <p>{{ item.reason }}</p>
+                  <small v-if="item.reviewComment">审核意见：{{ item.reviewComment }}</small>
                 </div>
-        <h4 style="margin-bottom:8px">缓考申请</h4>
-        <div class="appr-list" style="margin-bottom:16px">
-          <article v-for="d in myDeferred" :key="d.id" class="appr-card"><el-tag size="small" :type="d.status === 'Approved' ? 'success' : d.status === 'Rejected' ? 'danger' : 'warning'">{{ d.status === 'Submitted' ? '待审核' : d.status === 'Approved' ? '已通过' : '已驳回' }}</el-tag><div class="appr-body"><b>{{ d.courseName }}</b><p>{{ d.reason }}</p></div></article>
-          <el-empty v-if="!myDeferred.length" description="无" />
+              </article>
+              <p v-if="!myExemptions.length" class="record-empty">尚未提交免修申请</p>
             </div>
+          </section>
+          <section class="record-group">
+            <header><span class="record-mark deferred"></span><b>缓考申请</b><em>{{ myDeferred.length }}</em></header>
+            <div class="appr-list">
+              <article v-for="item in myDeferred" :key="item.id" class="appr-card compact">
+                <el-tag size="small" :type="statusType(item.status)">{{ statusText(item.status) }}</el-tag>
+                <div class="appr-body">
+                  <b>{{ item.courseName }}</b>
+                  <p>{{ item.reason }}</p>
+                  <small v-if="item.reviewComment">审核意见：{{ item.reviewComment }}</small>
+                </div>
+              </article>
+              <p v-if="!myDeferred.length" class="record-empty">尚未提交缓考申请</p>
+            </div>
+          </section>
+          <section class="record-group substitution-records">
+            <header><span class="record-mark substitution"></span><b>课程替代申请</b><em>{{ mySubstitutions.length }}</em></header>
+            <div class="appr-list">
+              <article v-for="item in mySubstitutions" :key="item.id" class="appr-card compact">
+                <el-tag size="small" :type="statusType(item.status)">{{ statusText(item.status) }}</el-tag>
+                <div class="appr-body">
+                  <b>{{ item.substituteCourseCode }} {{ item.substituteCourseName }} → {{ item.originalCourseCode }} {{ item.originalCourseName }}</b>
+                  <p>{{ item.reason }}</p>
+                  <small v-if="item.reviewComment">审核意见：{{ item.reviewComment }}</small>
+                </div>
+              </article>
+              <p v-if="!mySubstitutions.length" class="record-empty">尚未提交课程替代申请</p>
+            </div>
+          </section>
+        </div>
+        <el-empty v-else description="还没有申请记录">
+          <el-button type="primary" @click="openDialog('exemption')">发起第一项申请</el-button>
+        </el-empty>
       </template>
     </section>
 
-    <!-- Dialog -->
-    <el-dialog v-model="dialog" :title="dialogType === 'exemption' ? '免修申请' : dialogType === 'deferred' ? '缓考申请' : dialogType === 'gradeMod' ? '成绩修改申请' : '课程替代申请'" width="560px">
+    <el-dialog v-model="dialog" :title="dialogTitle" width="min(780px, calc(100vw - 24px))" class="application-dialog" destroy-on-close>
       <el-form label-position="top">
         <template v-if="dialogType === 'exemption' || dialogType === 'deferred'">
-          <el-form-item label="选择课程" required>
-            <el-select v-model="form.teachingTaskId" filterable><el-option v-for="c in enrolledCourses" :key="c.teachingTaskId" :label="`${c.courseCode} ${c.courseName}`" :value="c.teachingTaskId" /></el-select>
+          <div class="dialog-lead">
+            <span :class="['dialog-lead-icon', dialogType]">
+              <DocumentChecked v-if="dialogType === 'exemption'" />
+              <Clock v-else />
+            </span>
+            <div>
+              <b>{{ dialogType === 'exemption' ? '选择申请免修的教学班' : '选择申请缓考的教学班' }}</b>
+              <p>列表包含当前学期课程，以及仍未归档且课表已发布的行政班或已选课程。</p>
+            </div>
+          </div>
+          <el-form-item label="课程" required>
+            <el-input v-model="courseKeyword" :prefix-icon="Search" clearable placeholder="搜索课程名称、代码、教学班号或教师" />
+            <div v-if="filteredCourses.length" class="course-picker">
+              <button
+                v-for="course in filteredCourses"
+                :key="course.teachingTaskId"
+                type="button"
+                :class="['course-choice', { selected: form.teachingTaskId === course.teachingTaskId }]"
+                @click="form.teachingTaskId = course.teachingTaskId"
+              >
+                <span class="course-code">{{ course.courseCode }}</span>
+                <span class="course-main">
+                  <b>{{ course.courseName }}</b>
+                  <small>{{ course.taskNumber }} · {{ course.academicTermName }}</small>
+                  <em>{{ course.teacherNames.length ? course.teacherNames.join('、') : '教师待定' }} · {{ course.credits }} 学分</em>
+                </span>
+                <span :class="['schedule-state', { ready: course.hasPublishedSchedule || course.schedulingMode === 'Flexible' }]">
+                  {{ courseScheduleText(course) }}
+                </span>
+                <span class="choice-check"><Check /></span>
+              </button>
+            </div>
+            <el-empty
+              v-else
+              :description="enrolledCourses.length ? '没有匹配的课程' : '暂无可申请课程'"
+              :image-size="76"
+            >
+              <p v-if="!enrolledCourses.length" class="empty-explanation">
+                课程需为已发布教学任务，并分配到您的行政班或已完成选课；当前学期课程或已发布课表的课程均会显示。
+              </p>
+            </el-empty>
           </el-form-item>
         </template>
+
         <template v-if="dialogType === 'substitution'">
-          <el-form-item label="未通过课程（被替代）" required>
-            <el-select v-model="form.originalCourseId" filterable><el-option v-for="g in myGrades.filter((x:any) => Number(x.totalScore) < 60)" :key="g.courseId" :label="`${g.courseCode} ${g.courseName} (${g.totalScore}分)`" :value="g.courseId" /></el-select>
-          </el-form-item>
-          <el-form-item label="已通过课程（替代课程）" required>
-            <el-select v-model="form.substituteCourseId" filterable><el-option v-for="g in myGrades.filter((x:any) => Number(x.totalScore) >= 60)" :key="g.courseId" :label="`${g.courseCode} ${g.courseName} (${g.totalScore}分)`" :value="g.courseId" /></el-select>
-          </el-form-item>
+          <el-alert
+            title="替代关系须同时满足两个条件"
+            description="被替代课程应为当前或已发布课表的修读课程，或已有未通过成绩的课程；替代课程必须已有正式发布且不低于 60 分的成绩。"
+            type="info"
+            :closable="false"
+            show-icon
+          />
+          <div class="substitution-flow">
+            <section class="substitution-column">
+              <header><span>1</span><div><b>被替代课程</b><small>修读课程 / 历史未通过</small></div></header>
+              <el-input v-model="originalKeyword" :prefix-icon="Search" clearable placeholder="搜索课程" />
+              <div v-if="filteredOriginalCourses.length" class="mini-course-list">
+                <button
+                  v-for="course in filteredOriginalCourses"
+                  :key="course.courseId"
+                  type="button"
+                  :class="{ selected: form.originalCourseId === course.courseId }"
+                  @click="selectOriginal(course.courseId)"
+                >
+                  <span><b>{{ course.courseCode }} · {{ course.courseName }}</b><small>{{ course.detail }} · {{ course.credits }} 学分</small></span>
+                  <el-tag size="small" :type="course.source === 'assigned' ? 'primary' : 'danger'">
+                    {{ course.source === 'assigned' ? '修读' : '未通过' }}
+                  </el-tag>
+                </button>
+              </div>
+              <el-empty v-else :image-size="62" description="暂无可被替代课程" />
+            </section>
+            <div class="flow-arrow">→</div>
+            <section class="substitution-column">
+              <header><span>2</span><div><b>替代课程</b><small>已发布且成绩及格</small></div></header>
+              <el-input v-model="substituteKeyword" :prefix-icon="Search" clearable placeholder="搜索课程" />
+              <div v-if="filteredSubstituteCourses.length" class="mini-course-list">
+                <button
+                  v-for="course in filteredSubstituteCourses"
+                  :key="course.courseId"
+                  type="button"
+                  :disabled="course.courseId === form.originalCourseId"
+                  :class="{ selected: form.substituteCourseId === course.courseId }"
+                  @click="form.substituteCourseId = course.courseId"
+                >
+                  <span><b>{{ course.courseCode }} · {{ course.courseName }}</b><small>{{ course.academicTermName }} · {{ course.credits }} 学分</small></span>
+                  <strong>{{ course.totalScore }}<small>分</small></strong>
+                </button>
+              </div>
+              <el-empty v-else :image-size="62" description="暂无已通过课程">
+                <p class="empty-explanation">已排课但尚未发布成绩的课程不属于可替代课程。</p>
+              </el-empty>
+            </section>
+          </div>
         </template>
+
         <template v-if="dialogType === 'gradeMod'">
           <el-form-item label="成绩记录" required>
-            <el-select v-model="form.gradeRecordId" filterable><el-option v-for="r in gradeRecords" :key="r.id" :label="`${r.studentName}(${r.studentNumber}) — ${r.courseName} — ${r.totalScore}分`" :value="r.id" /></el-select>
+            <el-select v-model="form.gradeRecordId" filterable placeholder="选择已发布成绩">
+              <el-option
+                v-for="record in gradeRecords"
+                :key="record.id"
+                :label="`${record.studentName}(${record.studentNumber}) — ${record.courseName} — ${record.totalScore}分`"
+                :value="record.id"
+              />
+            </el-select>
+          </el-form-item>
+          <el-form-item label="修改为" required>
+            <el-input-number v-model="form.requestedScore" :min="0" :max="100" />
           </el-form-item>
-          <el-form-item label="修改为" required><el-input-number v-model="form.requestedScore" :min="0" :max="100" /></el-form-item>
         </template>
-        <el-form-item label="原因" required><el-input v-model="form.reason" type="textarea" :rows="3" maxlength="500" show-word-limit /></el-form-item>
+
+        <el-form-item class="reason-field" label="申请原因" required>
+          <el-input
+            v-model="form.reason"
+            type="textarea"
+            :rows="4"
+            maxlength="500"
+            show-word-limit
+            :placeholder="dialogType === 'deferred' ? '请说明无法按时参加考试的原因及相关情况' : dialogType === 'substitution' ? '请说明两门课程在内容、学分或培养要求上的对应关系' : '请说明申请依据及相关情况'"
+          />
+        </el-form-item>
       </el-form>
-      <template #footer><el-button @click="dialog = false">取消</el-button><el-button type="primary" @click="submitForm">提交申请</el-button></template>
+      <template #footer>
+        <div class="dialog-footer">
+          <span v-if="selectedCourse">{{ selectedCourse.courseCode }} · {{ selectedCourse.courseName }}</span>
+          <span v-else-if="selectedOriginal || selectedSubstitute">
+            {{ selectedSubstitute?.courseName ?? '请选择替代课程' }} → {{ selectedOriginal?.courseName ?? '请选择被替代课程' }}
+          </span>
+          <el-button @click="dialog = false">取消</el-button>
+          <el-button type="primary" :loading="submitting" @click="submitForm">提交申请</el-button>
+        </div>
+      </template>
     </el-dialog>
 
-    <!-- Reject -->
-    <el-dialog v-model="rejectDialog" title="驳回" width="460px">
-      <el-input v-model="rejectComment" type="textarea" :rows="3" maxlength="500" show-word-limit placeholder="驳回原因" />
-      <template #footer><el-button @click="rejectDialog = false">取消</el-button><el-button type="danger" @click="rejectSubmit">确认驳回</el-button></template>
+    <el-dialog v-model="rejectDialog" title="驳回申请" width="min(460px, calc(100vw - 24px))">
+      <el-input v-model="rejectComment" type="textarea" :rows="3" maxlength="500" show-word-limit placeholder="请填写驳回原因" />
+      <template #footer>
+        <el-button @click="rejectDialog = false">取消</el-button>
+        <el-button type="danger" @click="rejectSubmit">确认驳回</el-button>
+      </template>
     </el-dialog>
   </div>
 </template>
 
 <style scoped>
+.application-launcher {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 12px;
+}
+
+.launch-card {
+  position: relative;
+  min-height: 132px;
+  padding: 20px;
+  display: flex;
+  align-items: flex-start;
+  gap: 14px;
+  overflow: hidden;
+  text-align: left;
+  color: #1e293b;
+  background: linear-gradient(145deg, #fff 48%, #f6f8fb);
+  border: 1px solid #dfe4eb;
+  border-radius: 14px;
+  cursor: pointer;
+  transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease;
+}
+
+.launch-card::after {
+  content: "";
+  position: absolute;
+  right: -26px;
+  bottom: -50px;
+  width: 120px;
+  height: 120px;
+  border: 18px solid rgba(67, 97, 238, .05);
+  border-radius: 50%;
+}
+
+.launch-card:hover {
+  transform: translateY(-2px);
+  border-color: #aebbd0;
+  box-shadow: 0 12px 28px rgba(30, 41, 59, .08);
+}
+
+.launch-icon, .dialog-lead-icon {
+  width: 42px;
+  height: 42px;
+  flex: 0 0 auto;
+  display: grid;
+  place-items: center;
+  color: #3556b5;
+  background: #edf2ff;
+  border-radius: 12px;
+}
+
+.launch-icon svg, .dialog-lead-icon svg { width: 21px; }
+.deferred .launch-icon, .dialog-lead-icon.deferred { color: #a85d00; background: #fff3dc; }
+.substitution .launch-icon { color: #087f5b; background: #e8f8f1; }
+.launch-copy { display: grid; gap: 3px; min-width: 0; }
+.launch-copy small { color: #8791a3; font: 600 9px/1.2 ui-monospace, monospace; letter-spacing: .1em; }
+.launch-copy b { margin-top: 3px; font-size: 17px; }
+.launch-copy em { color: #667085; font-size: 11px; font-style: normal; line-height: 1.5; }
+.launch-meta { position: absolute; left: 76px; bottom: 17px; display: flex; align-items: center; gap: 5px; color: #506079; font-size: 10px; }
+.launch-meta svg { width: 12px; }
+
+.approval-tabs { display: flex; justify-content: space-between; gap: 12px; }
 .appr-list { display: grid; gap: 8px; }
-.appr-card { display: flex; align-items: center; gap: 14px; padding: 14px 18px; background: #fff; border: 1px solid #e4e7ed; border-radius: 8px; }
+.appr-card { display: flex; align-items: center; gap: 14px; padding: 14px 18px; background: #fff; border: 1px solid #e4e7ed; border-radius: 10px; }
+.appr-card.compact { align-items: flex-start; padding: 13px; }
 .appr-body { flex: 1; min-width: 0; }
-.appr-body b { font-size: 14px; display: block; margin-bottom: 4px; }
-.appr-body p { font-size: 13px; color: #606266; margin: 0 0 4px; }
-.appr-body small { font-size: 11px; color: var(--muted); }
-.appr-actions { display: flex; gap: 6px; flex-shrink: 0; }
+.appr-body b { display: block; margin-bottom: 4px; font-size: 13px; }
+.appr-body p { margin: 0 0 4px; color: #606266; font-size: 12px; line-height: 1.55; }
+.appr-body small { color: var(--muted); font-size: 10px; }
+.appr-actions { display: flex; flex-shrink: 0; gap: 6px; }
+
+.record-columns { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; align-items: start; }
+.record-group { padding: 16px; background: #f8fafc; border: 1px solid #e5e9f0; border-radius: 12px; }
+.record-group.substitution-records { grid-column: 1 / -1; }
+.record-group > header { margin-bottom: 12px; display: flex; align-items: center; gap: 8px; }
+.record-group > header b { font-size: 13px; }
+.record-group > header em { margin-left: auto; min-width: 22px; padding: 3px 7px; color: #667085; background: #fff; border-radius: 10px; font-size: 10px; font-style: normal; text-align: center; }
+.record-mark { width: 8px; height: 8px; background: #4b6fd8; border-radius: 50%; box-shadow: 0 0 0 4px #e8edfb; }
+.record-mark.deferred { background: #d5841c; box-shadow: 0 0 0 4px #fff0d8; }
+.record-mark.substitution { background: #13916a; box-shadow: 0 0 0 4px #dff5ed; }
+.record-empty { margin: 20px 0; color: #98a2b3; font-size: 11px; text-align: center; }
+
+.dialog-lead { margin-bottom: 18px; padding: 14px; display: flex; align-items: center; gap: 12px; background: #f7f9fc; border: 1px solid #e6eaf1; border-radius: 10px; }
+.dialog-lead b { display: block; margin-bottom: 3px; font-size: 13px; }
+.dialog-lead p { margin: 0; color: #667085; font-size: 11px; }
+.course-picker { width: 100%; max-height: 330px; margin-top: 10px; display: grid; gap: 8px; overflow: auto; }
+.course-choice { width: 100%; padding: 13px; display: grid; grid-template-columns: 68px minmax(0, 1fr) auto 20px; align-items: center; gap: 12px; text-align: left; background: #fff; border: 1px solid #e1e6ee; border-radius: 10px; cursor: pointer; transition: border-color .15s, background .15s; }
+.course-choice:hover { border-color: #9aabd4; }
+.course-choice.selected { background: #f4f7ff; border-color: #4b6fd8; box-shadow: inset 3px 0 #4b6fd8; }
+.course-code { color: #3651a3; font: 700 11px/1.3 ui-monospace, monospace; }
+.course-main { display: grid; min-width: 0; gap: 3px; }
+.course-main b { color: #1e293b; font-size: 13px; }
+.course-main small, .course-main em { overflow: hidden; color: #7b8495; font-size: 10px; font-style: normal; text-overflow: ellipsis; white-space: nowrap; }
+.schedule-state { padding: 4px 7px; color: #8a6116; background: #fff4d9; border-radius: 6px; font-size: 9px; }
+.schedule-state.ready { color: #087f5b; background: #e5f7ef; }
+.choice-check { display: grid; place-items: center; width: 18px; height: 18px; color: transparent; border: 1px solid #cfd5df; border-radius: 50%; }
+.choice-check svg { width: 11px; }
+.course-choice.selected .choice-check { color: #fff; background: #4b6fd8; border-color: #4b6fd8; }
+.empty-explanation { max-width: 450px; margin: -10px auto 0; color: #8992a3; font-size: 10px; line-height: 1.6; }
+
+.substitution-flow { margin-top: 16px; display: grid; grid-template-columns: minmax(0, 1fr) 24px minmax(0, 1fr); align-items: stretch; gap: 10px; }
+.substitution-column { min-width: 0; padding: 14px; background: #f8fafc; border: 1px solid #e5e9f0; border-radius: 12px; }
+.substitution-column > header { margin-bottom: 12px; display: flex; align-items: center; gap: 9px; }
+.substitution-column > header > span { width: 25px; height: 25px; display: grid; place-items: center; color: #fff; background: #405fb7; border-radius: 8px; font: 700 11px/1 ui-monospace, monospace; }
+.substitution-column > header div { display: grid; gap: 2px; }
+.substitution-column > header b { font-size: 12px; }
+.substitution-column > header small { color: #8a94a5; font-size: 9px; }
+.flow-arrow { display: grid; place-items: center; color: #7d8fbf; font-size: 18px; }
+.mini-course-list { max-height: 255px; margin-top: 9px; display: grid; align-content: start; gap: 6px; overflow: auto; }
+.mini-course-list button { padding: 10px; display: flex; align-items: center; gap: 8px; text-align: left; background: #fff; border: 1px solid #e2e7ee; border-radius: 8px; cursor: pointer; }
+.mini-course-list button:hover { border-color: #a9b5d3; }
+.mini-course-list button.selected { background: #f0f4ff; border-color: #4b6fd8; box-shadow: inset 3px 0 #4b6fd8; }
+.mini-course-list button:disabled { opacity: .45; cursor: not-allowed; }
+.mini-course-list button > span { min-width: 0; display: grid; flex: 1; gap: 3px; }
+.mini-course-list button b { overflow: hidden; font-size: 11px; text-overflow: ellipsis; white-space: nowrap; }
+.mini-course-list button span small { color: #8a94a5; font-size: 9px; }
+.mini-course-list button > strong { color: #087f5b; font-size: 16px; }
+.mini-course-list button > strong small { margin-left: 1px; font-size: 8px; font-weight: 500; }
+.reason-field { margin-top: 18px; }
+.dialog-footer { display: flex; align-items: center; justify-content: flex-end; gap: 8px; }
+.dialog-footer > span { margin-right: auto; overflow: hidden; color: #667085; font-size: 10px; text-overflow: ellipsis; white-space: nowrap; }
+
+@media (max-width: 860px) {
+  .application-launcher { grid-template-columns: 1fr; }
+  .launch-card { min-height: 112px; }
+  .record-columns { grid-template-columns: 1fr; }
+  .record-group.substitution-records { grid-column: auto; }
+  .substitution-flow { grid-template-columns: 1fr; }
+  .flow-arrow { transform: rotate(90deg); }
+}
+
+@media (max-width: 600px) {
+  .page-intro { align-items: flex-start; }
+  .approval-tabs { align-items: flex-start; }
+  .course-choice { grid-template-columns: 58px minmax(0, 1fr) 18px; }
+  .schedule-state { grid-column: 2; justify-self: start; }
+  .appr-card { align-items: flex-start; flex-wrap: wrap; }
+  .appr-actions { width: 100%; justify-content: flex-end; }
+}
 </style>