Merge branch 'el-ui' into main (prefer el-ui on conflicts)

docs/course-management-api-integration.md

@@ -0,0 +1,479 @@
+# Course Management API Integration Guide
+
+This document describes the Course Management related APIs used by the admin frontend (`Yimaru-Admin`) and how to integrate them safely.
+
+It is based on:
+- `src/api/courses.api.ts`
+- `src/api/files.api.ts`
+- `src/types/course.types.ts`
+- `src/api/http.ts`
+
+---
+
+## 1) Base setup and auth behavior
+
+### Base URL
+- All requests use `VITE_API_BASE_URL` from environment.
+
+### Authentication
+- Access token is sent automatically as `Authorization: Bearer <access_token>`.
+- On `401`, the frontend attempts token refresh via:
+  - `POST /auth/refresh`
+  - payload: `{ access_token, refresh_token, role, member_id }`
+- If refresh fails, auth data is cleared and user is redirected to `/login`.
+
+### Transport notes
+- Axios automatically handles `multipart/form-data` boundaries for file upload.
+- Any network failure without response also redirects to `/login` (current client behavior).
+
+---
+
+## 2) Core domain model used by frontend
+
+Current hierarchy used by content management:
+- `Category`
+  - `Sub-category`
+    - `Course`
+      - `Level (CEFR)`
+        - `Module`
+          - `Sub-module`
+            - `Videos`
+            - `Lessons` (question sets with `set_type = QUIZ`)
+            - `Practices` (question sets with `set_type = PRACTICE`)
+
+Important migration note:
+- Some APIs/types are marked as legacy (`Program`, old `Level/Module` flows).
+- Current frontend mostly uses unified hierarchy endpoints under `/course-management/...` plus `/question-sets` and `/questions`.
+
+---
+
+## 3) File/media APIs (used by course management)
+
+## 3.1 Upload media
+
+### Endpoint
+- `POST /files/upload`
+
+### Supports
+- `media_type`: `"image" | "audio" | "video"`
+- File upload via multipart (`file`) or URL import via JSON (`source_url`).
+
+### For video uploads
+- Can send optional `title` and `description`.
+
+### Typical response fields used by frontend
+- `data.object_key`
+- `data.url`
+- `data.provider` (`MINIO` or `VIMEO`)
+- `data.vimeo_id`
+- `data.embed_url`
+
+### Frontend wrapper functions
+- `uploadAudioFile(fileOrUrl)`
+- `uploadImageFile(fileOrUrl)`
+- `uploadVideoFile(fileOrUrl, { title?, description? })`
+
+## 3.2 Resolve object key to URL
+
+### Endpoint
+- `GET /files/url?key=<object_key>`
+
+### Use case
+- Resolve media object key when only key is stored.
+
+---
+
+## 4) Category and course APIs
+
+## 4.1 Get categories (normalized in frontend)
+
+### Endpoint called
+- `GET /course-management/hierarchy`
+
+### Frontend behavior
+- Client transforms flat hierarchy rows into category list.
+- Duplicated category names are merged client-side by "richest" record.
+
+### Wrapper
+- `getCourseCategories()`
+
+## 4.2 Create category or sub-category
+
+### Category
+- `POST /course-management/categories`
+- body: `{ name }`
+
+### Sub-category
+- `POST /course-management/sub-categories`
+- body: `{ category_id, name }`
+
+### Wrapper
+- `createCourseCategory({ name, parent_id? })`
+  - if `parent_id` exists, creates sub-category; else category.
+
+## 4.3 Delete category/sub-category
+- `DELETE /course-management/categories/:categoryId`
+- `DELETE /course-management/sub-categories/:subCategoryId`
+
+Wrappers:
+- `deleteCourseCategory(categoryId)`
+- `deleteCourseSubCategory(subCategoryId)`
+
+## 4.4 Courses by category
+
+### Endpoint called
+- `GET /course-management/hierarchy`
+
+### Frontend behavior
+- Filters and maps rows to courses client-side.
+- If duplicate category names exist, it includes rows matching requested category name.
+
+Wrapper:
+- `getCoursesByCategory(categoryId)`
+
+## 4.5 Course CRUD
+- `POST /course-management/courses`
+- `PUT /course-management/courses/:courseId`
+- `PUT /course-management/courses/:courseId` (status toggle via `is_active`)
+- `DELETE /course-management/courses/:courseId`
+- `POST /course-management/courses/:courseId/thumbnail`
+
+Wrappers:
+- `createCourse(data)`
+- `updateCourse(courseId, data)`
+- `updateCourseStatus(courseId, isActive)`
+- `deleteCourse(courseId)`
+- `updateCourseThumbnail(courseId, thumbnailUrl)`
+
+---
+
+## 5) Course hierarchy (levels/modules/sub-modules)
+
+## 5.1 Get full hierarchy for one course
+
+### Endpoint
+- `GET /course-management/courses/:courseId/hierarchy`
+
+### Wrapper
+- `getSubModulesByCourse(courseId)`
+
+### Frontend behavior
+- Maps hierarchy rows into `sub_courses` shape (compatibility naming).
+- This is the primary source for module/sub-module tree rendering.
+
+## 5.2 Create sub-module flow (composed)
+
+`createSubModule(data)` is a multi-step client workflow:
+1. `POST /course-management/levels`
+2. `POST /course-management/modules`
+3. `POST /course-management/sub-modules`
+
+Use this when creating a new sub-module from minimal info.
+
+## 5.3 Direct level/module/sub-module creation
+- `createModuleInLevel(levelId, title, description, displayOrder?)`
+  - `POST /course-management/modules`
+- `createSubModuleInModule(moduleId, title, description, displayOrder?)`
+  - `POST /course-management/sub-modules`
+
+## 5.4 Update/delete sub-module
+- `PUT /course-management/sub-modules/:subModuleId`
+- `PUT /course-management/sub-modules/:subModuleId` (status payload)
+- `DELETE /course-management/sub-modules/:subModuleId`
+- `POST /course-management/sub-courses/:subModuleId/thumbnail` (compat endpoint)
+
+Wrappers:
+- `updateSubModule(...)`
+- `updateSubModuleStatus(...)`
+- `deleteSubModule(...)`
+- `updateSubModuleThumbnail(...)`
+
+---
+
+## 6) Video APIs (sub-module videos)
+
+## 6.1 List videos for sub-module
+- `GET /course-management/sub-modules/:subModuleId/videos`
+- wrapper: `getVideosBySubModule(subModuleId)`
+
+## 6.2 Create video
+
+Two wrapper variants, same endpoint:
+- `POST /course-management/sub-module-videos`
+
+### Minimal variant
+- `createSubCourseVideo({ sub_module_id|sub_course_id, title, description, video_url })`
+
+### Extended variant
+- `createCourseVideo({ sub_module_id|sub_course_id, title, description, video_url, duration, resolution?, visibility?, display_order?, status? })`
+
+## 6.3 Update/delete video
+- `PUT /course-management/sub-module-videos/:videoId`
+- `DELETE /course-management/sub-module-videos/:videoId`
+
+Wrappers:
+- `updateSubCourseVideo(videoId, data)`
+- `deleteSubCourseVideo(videoId)`
+
+---
+
+## 7) Practices and lessons
+
+## 7.1 Practices by sub-module
+- `GET /question-sets/by-owner?owner_type=SUB_MODULE&owner_id=:subModuleId`
+- wrapper: `getPracticesBySubModule(subModuleId)`
+
+## 7.2 Create practice (composed)
+
+`createPractice(data)` does:
+1. `POST /question-sets`
+   - `set_type: "PRACTICE"`
+   - `owner_type: "SUB_MODULE"`
+   - `owner_id: sub_module_id`
+2. If step 1 succeeds, links to sub-module practice:
+   - `POST /course-management/sub-module-practices`
+   - includes `question_set_id` and intro metadata
+
+## 7.3 Create lesson (composed)
+
+`createLesson(data)` does:
+1. `POST /question-sets`
+   - `set_type: "QUIZ"`
+   - `owner_type: "SUB_MODULE"`
+2. Link question set as lesson:
+   - `POST /course-management/sub-module-lessons`
+
+## 7.4 Practice update/delete/status
+- `PUT /course-management/practices/:practiceId`
+- `PUT /course-management/practices/:practiceId` (status)
+- `DELETE /course-management/practices/:practiceId`
+
+Wrappers:
+- `updatePractice(...)`
+- `updatePracticeStatus(...)`
+- `deletePractice(...)`
+
+---
+
+## 8) Question sets and questions
+
+## 8.1 Question sets
+- `GET /question-sets` with optional query params
+- `GET /question-sets/by-owner`
+- `GET /question-sets/:id`
+- `PUT /question-sets/:id`
+- `DELETE /question-sets/:id`
+- `POST /question-sets`
+
+Wrappers:
+- `getQuestionSets(params?)`
+- `getQuestionSetsByOwner(ownerType, ownerId)`
+- `getQuestionSetById(questionSetId)`
+- `createQuestionSet(data)`
+- `updateQuestionSet(questionSetId, partialData)`
+- `deleteQuestionSet(questionSetId)`
+
+## 8.2 Question list within set
+- `GET /question-sets/:questionSetId/questions`
+- `POST /question-sets/:questionSetId/questions` (add by question id)
+
+Wrappers:
+- `getQuestionSetQuestions(questionSetId)`
+- `addQuestionToSet(questionSetId, { question_id, display_order? })`
+
+## 8.3 Questions CRUD
+- `GET /questions` (filters)
+- `GET /questions/:questionId`
+- `POST /questions`
+- `PUT /questions/:questionId`
+- `DELETE /questions/:questionId`
+
+Wrappers:
+- `getQuestions(params)`
+- `getQuestionById(questionId)`
+- `createQuestion(data)`
+- `updateQuestion(questionId, data)`
+- `deleteQuestion(questionId)`
+
+## 8.4 Practice-question convenience wrappers
+
+`createPracticeQuestion(data)`:
+1. Creates question via `POST /questions`
+2. Adds it to practice set via `POST /question-sets/:practiceId/questions`
+
+`updatePracticeQuestion(questionId, data)`:
+- maps to `PUT /questions/:questionId`
+
+`deletePracticeQuestion(questionId)`:
+- `DELETE /questions/:questionId`
+
+## 8.5 Practice question listing endpoint variants
+- `getPracticeQuestions(practiceId)` -> `GET /question-sets/:practiceId/questions`
+- `getPracticeQuestionsByPractice(practiceId, params)` -> `GET /practices/:practiceId/questions`
+
+Use the second when you need pagination/filtering by question type.
+
+---
+
+## 9) Human language specific APIs
+
+## 9.1 Human language hierarchy
+- `getHumanLanguageHierarchy()`
+- Calls `GET /course-management/hierarchy`
+- If backend already returns nested `sub_categories`, uses it directly.
+- If backend returns flat rows, client builds nested structure and enriches each course by:
+  - requesting `/course-management/courses/:courseId/hierarchy`
+  - requesting `/question-sets/by-owner` per sub-module
+  - deriving lessons from question sets where `set_type = "QUIZ"`
+
+This method is heavier than basic endpoints and can issue many requests.
+
+## 9.2 Human language lessons by course+level
+- `GET /course-management/human-language/courses/:courseId/lessons?cefr_level=...`
+- wrapper: `getHumanLanguageLessonsByCourse(courseId, cefrLevel)`
+
+## 9.3 Create human language lesson structure
+
+`createHumanLanguageLesson(data)` is composed:
+1. `POST /course-management/levels`
+2. `POST /course-management/modules`
+3. `POST /course-management/sub-modules`
+
+---
+
+## 10) Learning path and assessments
+
+- `GET /course-management/courses/:courseId/learning-path`
+  - wrapper: `getLearningPath(courseId)`
+
+- `GET /question-sets/sub-courses/:subModuleId/entry-assessment`
+  - wrapper: `getSubModuleEntryAssessment(subModuleId)`
+
+---
+
+## 11) Unsupported or stubbed features in current frontend API layer
+
+The following wrappers are intentionally stubbed in frontend and return resolved promises (no real backend call):
+- `getSubModulePrerequisites`
+- `addSubModulePrerequisite`
+- `removeSubModulePrerequisite`
+- `reorderCategories`
+- `reorderCourses`
+- `reorderSubModules`
+- `reorderVideos`
+- `reorderPractices`
+
+Implication:
+- UI may appear to support these flows, but persistence is not implemented through backend yet.
+
+---
+
+## 12) Legacy endpoints still exposed (backward compatibility)
+
+These are still present in `courses.api.ts` but marked deprecated in types:
+- Programs APIs
+- Old levels APIs
+- Old modules APIs
+- Practices by level/module APIs
+
+Prefer unified hierarchy/sub-module/question-set APIs for new work.
+
+---
+
+## 13) Integration patterns and recommendations
+
+## 13.1 Safe creation flows
+- For practice/lesson creation, keep composed behavior:
+  - create question set first
+  - then link to sub-module entity
+- Handle partial failure:
+  - if link step fails after question set creation, frontend should show recoverable error and optionally support manual relink.
+
+## 13.2 Request normalization
+- `getQuestionSetsResponse.data` can be either:
+  - raw array
+  - object with `question_sets`
+- Normalize before rendering.
+
+## 13.3 Question type mapping
+- UI uses `"SHORT"`; backend commonly expects `"SHORT_ANSWER"`.
+- Existing wrappers already map `"SHORT"` to `"SHORT_ANSWER"` on create/update practice question.
+
+## 13.4 Media handling
+- Prefer using `/files/upload` wrappers for all media.
+- For Vimeo-backed responses, frontend typically consumes `embed_url` (and may append hash from page URL where applicable).
+
+## 13.5 Retry behavior
+- Some hierarchy fetches use single retry (`withSingleRetry`) for resiliency against transient auth/network race conditions.
+
+---
+
+## 14) Quick endpoint index
+
+### Course management
+- `GET /course-management/hierarchy`
+- `POST /course-management/categories`
+- `POST /course-management/sub-categories`
+- `DELETE /course-management/categories/:id`
+- `DELETE /course-management/sub-categories/:id`
+- `POST /course-management/courses`
+- `PUT /course-management/courses/:id`
+- `DELETE /course-management/courses/:id`
+- `POST /course-management/courses/:id/thumbnail`
+- `GET /course-management/courses/:courseId/hierarchy`
+- `POST /course-management/levels`
+- `POST /course-management/modules`
+- `PUT /course-management/levels/:id`
+- `DELETE /course-management/levels/:id`
+- `PUT /course-management/modules/:id`
+- `DELETE /course-management/modules/:id`
+- `POST /course-management/sub-modules`
+- `PUT /course-management/sub-modules/:id`
+- `DELETE /course-management/sub-modules/:id`
+- `GET /course-management/sub-modules/:subModuleId/videos`
+- `POST /course-management/sub-module-videos`
+- `PUT /course-management/sub-module-videos/:id`
+- `DELETE /course-management/sub-module-videos/:id`
+- `POST /course-management/sub-module-practices`
+- `POST /course-management/sub-module-lessons`
+- `GET /course-management/courses/:courseId/learning-path`
+- `GET /course-management/human-language/courses/:courseId/lessons`
+
+### Question sets and questions
+- `GET /question-sets`
+- `GET /question-sets/by-owner`
+- `GET /question-sets/:id`
+- `POST /question-sets`
+- `PUT /question-sets/:id`
+- `DELETE /question-sets/:id`
+- `GET /question-sets/:id/questions`
+- `POST /question-sets/:id/questions`
+- `GET /practices/:practiceId/questions`
+- `GET /questions`
+- `GET /questions/:id`
+- `POST /questions`
+- `PUT /questions/:id`
+- `DELETE /questions/:id`
+- `POST /questions/audio-answer`
+
+### File/media
+- `POST /files/upload`
+- `GET /files/url`
+- `GET /vimeo/sample`
+- `POST /vimeo/uploads/pull`
+
+---
+
+## 15) Suggested frontend service contract shape
+
+For any new frontend module, follow this contract:
+- **Input DTOs**: UI-friendly types (can include UI aliases like `SHORT`)
+- **Mapper layer**: convert UI DTOs to backend DTOs
+- **Transport layer**: pure API calls
+- **Normalizer layer**: normalize polymorphic responses (`array` vs `object`)
+- **Error policy**:
+  - show user-actionable toast
+  - preserve enough context to retry failed composed steps
+
+This keeps integration robust even with mixed legacy/unified backend surfaces.
+

src/api/courses.api.ts

@@ -47,8 +47,20 @@ import type {
   GetSubCoursePrerequisitesResponse,
   AddSubCoursePrerequisiteRequest,
   GetLearningPathResponse,
+  GetSubModuleLessonDetailResponse,
   GetHumanLanguageLessonsResponse,
-  GetHumanLanguageHierarchyResponse,
+  GetSubModuleLessonsResponse,
+  GetHumanLanguageSubCategoriesResponse,
+  GetCategorySubCategoriesResponse,
+  GetSubCategoryCoursesResponse,
+  GetCourseLevelsForCourseResponse,
+  GetCourseLevelsAllResponse,
+  GetCourseLevelByIdResponse,
+  GetHumanLanguageHierarchyFlatResponse,
+  GetCourseHierarchyResponse,
+  GetSubModulesByModuleResponse,
+  CourseHierarchyRow,
+  SubCourse,
   CreateHumanLanguageLessonRequest,
   GetSubCourseEntryAssessmentResponse,
   ReorderItem,
@@ -56,6 +68,8 @@ import type {
   GetRatingsParams,
   GetVimeoSampleResponse,
   CreateCourseVideoRequest,
+  UpdateSubModuleLessonRequest,
+  UpdateSubModuleLessonResponse,
 } from "../types/course.types"
 
 type UnifiedHierarchyRow = {
@@ -67,21 +81,22 @@ type UnifiedHierarchyRow = {
   course_title?: string | null
 }
 
-type CourseHierarchyRow = {
+async function withSingleRetry<T>(request: () => Promise<T>, retryDelayMs = 400): Promise<T> {
-  course_id: number
+  try {
-  course_title: string
+    return await request()
-  level_id?: number | null
+  } catch {
-  cefr_level?: string | null
+    await new Promise((resolve) => setTimeout(resolve, retryDelayMs))
-  module_id?: number | null
+    return request()
-  module_title?: string | null
+  }
-  sub_module_id?: number | null
-  sub_module_title?: string | null
 }
 
 export const getCourseCategories = () =>
-  http.get("/course-management/hierarchy").then((res) => {
+  withSingleRetry(() => http.get("/course-management/hierarchy")).then((res) => {
     const rows: UnifiedHierarchyRow[] = res.data?.data ?? []
-    const categoriesMap = new Map<number, { id: number; name: string; is_active: boolean; created_at: string }>()
+    const categoriesMap = new Map<
+      number,
+      { id: number; name: string; is_active: boolean; created_at: string; subCategoryCount: number; courseCount: number }
+    >()
     rows.forEach((r) => {
       if (!categoriesMap.has(r.category_id)) {
         categoriesMap.set(r.category_id, {
@@ -89,10 +104,50 @@ export const getCourseCategories = () =>
           name: r.category_name,
           is_active: true,
           created_at: new Date().toISOString(),
+          subCategoryCount: 0,
+          courseCount: 0,
         })
       }
+      const category = categoriesMap.get(r.category_id)!
+      if (r.sub_category_id) category.subCategoryCount += 1
+      if (r.course_id) category.courseCount += 1
     })
-    const categories = Array.from(categoriesMap.values())
+
+    // Merge duplicate top-level category names by selecting the richest representative.
+    type CategoryAggregate = {
+      id: number
+      name: string
+      is_active: boolean
+      created_at: string
+      subCategoryCount: number
+      courseCount: number
+    }
+    const categoryByName = new Map<string, CategoryAggregate>()
+    Array.from(categoriesMap.values()).forEach((category) => {
+      const key = category.name.trim().toLowerCase()
+      const existing = categoryByName.get(key)
+      if (!existing) {
+        categoryByName.set(key, category)
+        return
+      }
+      if (category.subCategoryCount > existing.subCategoryCount) {
+        categoryByName.set(key, category)
+        return
+      }
+      if (category.subCategoryCount === existing.subCategoryCount && category.courseCount > existing.courseCount) {
+        categoryByName.set(key, category)
+        return
+      }
+      if (
+        category.subCategoryCount === existing.subCategoryCount &&
+        category.courseCount === existing.courseCount &&
+        category.id > existing.id
+      ) {
+        categoryByName.set(key, category)
+      }
+    })
+
+    const categories = Array.from(categoryByName.values()).map(({ subCategoryCount, courseCount, ...category }) => category)
     return {
       ...res,
       data: {
@@ -110,20 +165,61 @@ export const createCourseCategory = (data: CreateCourseCategoryRequest) =>
     ? http.post("/course-management/sub-categories", { category_id: data.parent_id, name: data.name })
     : http.post("/course-management/categories", { name: data.name })
 
+export const deleteCourseCategory = (categoryId: number) =>
+  http.delete(`/course-management/categories/${categoryId}`)
+
+export const deleteCourseSubCategory = (subCategoryId: number) =>
+  http.delete(`/course-management/sub-categories/${subCategoryId}`)
+
+export const getSubCategoriesByCategoryId = (categoryId: number) =>
+  http.get<GetCategorySubCategoriesResponse>(`/course-management/categories/${categoryId}/sub-categories`)
+
+export const createSubCategory = (payload: {
+  category_id: number
+  name: string
+  description?: string | null
+  display_order?: number
+}) => http.post("/course-management/sub-categories", payload)
+
+export const updateSubCategory = (
+  subCategoryId: number,
+  payload: Partial<{
+    name: string
+    description: string | null
+    is_active: boolean
+    display_order: number
+  }>,
+) => http.patch(`/course-management/sub-categories/${subCategoryId}`, payload)
+
 export const getCoursesByCategory = (categoryId: number) =>
-  http.get("/course-management/hierarchy").then((res) => {
+  withSingleRetry(() => http.get("/course-management/hierarchy")).then((res) => {
     const rows: UnifiedHierarchyRow[] = res.data?.data ?? []
-    const courses = rows
+
-      .filter((r) => r.category_id === categoryId && r.course_id)
+    const requestedCategoryRows = rows.filter((r) => r.category_id === categoryId)
-      .map((r) => ({
+    const requestedCategoryName = requestedCategoryRows.find((r) => !!r.category_name)?.category_name?.trim().toLowerCase()
-        id: Number(r.course_id),
+    const relevantRows = requestedCategoryName
-        category_id: r.category_id,
+      ? rows.filter((r) => r.category_name?.trim().toLowerCase() === requestedCategoryName)
-        sub_category_id: r.sub_category_id ?? null,
+      : requestedCategoryRows
-        title: r.course_title ?? "",
+
-        description: "",
+    const courseMap = new Map<number, { id: number; category_id: number; sub_category_id: number | null; title: string; description: string; thumbnail: string; is_active: boolean }>()
-        thumbnail: "",
+    relevantRows
-        is_active: true,
+      .filter((r) => r.course_id)
-      }))
+      .forEach((r) => {
+        const id = Number(r.course_id)
+        if (!Number.isFinite(id)) return
+        if (courseMap.has(id)) return
+        courseMap.set(id, {
+          id,
+          category_id: r.category_id,
+          sub_category_id: r.sub_category_id ?? null,
+          title: r.course_title ?? "",
+          description: "",
+          thumbnail: "",
+          is_active: true,
+        })
+      })
+    const courses = Array.from(courseMap.values())
+
     return {
       ...res,
       data: { ...res.data, data: { courses, total_count: courses.length } },
@@ -147,17 +243,39 @@ export const updateCourseStatus = (courseId: number, isActive: boolean) =>
 export const updateCourse = (courseId: number, data: UpdateCourseRequest) =>
   http.put(`/course-management/courses/${courseId}`, data)
 
+export const getCourseHierarchyByCourseId = (courseId: number) =>
+  http.get<GetCourseHierarchyResponse>(`/course-management/courses/${courseId}/hierarchy`)
+
 // Sub-Module APIs (Unified Hierarchy)
 export const getSubModulesByCourse = (courseId: number) =>
-  http.get(`/course-management/courses/${courseId}/hierarchy`).then((res) => {
+  getCourseHierarchyByCourseId(courseId).then((res) => {
-    const rows: CourseHierarchyRow[] = res.data?.data ?? []
+    const raw = res.data?.data
-    const subModuleMap = new Map<number, { id: number; course_id: number; module_id?: number; title: string; description: string; level: string; cefr_level?: string; thumbnail: string; display_order: number; sub_level?: string; is_active: boolean }>()
+    const rows: CourseHierarchyRow[] = Array.isArray(raw) ? raw : []
+    const subModuleMap = new Map<
+      number,
+      {
+        id: number
+        course_id: number
+        level_id?: number
+        module_id?: number
+        title: string
+        description: string
+        level: string
+        cefr_level?: string
+        thumbnail: string
+        display_order: number
+        sub_level?: string
+        is_active: boolean
+      }
+    >()
     rows.forEach((r, idx) => {
       if (!r.sub_module_id) return
-      if (!subModuleMap.has(r.sub_module_id)) {
+      const existing = subModuleMap.get(r.sub_module_id)
+      if (!existing) {
         subModuleMap.set(r.sub_module_id, {
           id: r.sub_module_id,
           course_id: courseId,
+          level_id: r.level_id ?? undefined,
           module_id: r.module_id ?? undefined,
           title: r.sub_module_title ?? "",
           description: "",
@@ -168,7 +286,17 @@ export const getSubModulesByCourse = (courseId: number) =>
           sub_level: r.cefr_level ?? undefined,
           is_active: true,
         })
+        return
       }
+      subModuleMap.set(r.sub_module_id, {
+        ...existing,
+        module_id: existing.module_id ?? r.module_id ?? undefined,
+        level_id: existing.level_id ?? r.level_id ?? undefined,
+        title: existing.title || r.sub_module_title || "",
+        level: existing.level || r.cefr_level || "",
+        cefr_level: existing.cefr_level ?? r.cefr_level ?? undefined,
+        sub_level: existing.sub_level ?? r.cefr_level ?? undefined,
+      })
     })
     const sub_courses = Array.from(subModuleMap.values())
     return {
@@ -225,6 +353,33 @@ export const deleteSubModule = (subModuleId: number) =>
 export const getVideosBySubModule = (subModuleId: number) =>
   http.get<GetSubCourseVideosResponse>(`/course-management/sub-modules/${subModuleId}/videos`)
 
+export const getLessonsBySubModule = (subModuleId: number, options?: { includeInactive?: boolean }) =>
+  http.get<GetSubModuleLessonsResponse>(`/course-management/sub-modules/${subModuleId}/lessons`, {
+    params: { include_inactive: options?.includeInactive ?? true },
+  })
+
+export const getSubModuleLessonById = (
+  lessonId: number,
+  options?: {
+    /**
+     * Cache-bust the request to avoid serving stale lesson data after edits.
+     * This is intentionally implemented via query string to work with default axios config.
+     */
+    cacheBust?: boolean
+  },
+) =>
+  http.get<GetSubModuleLessonDetailResponse>(`/course-management/sub-module-lessons/${lessonId}`, {
+    params: options?.cacheBust ? { _t: Date.now() } : undefined,
+  })
+
+export const updateSubModuleLesson = (lessonId: number, data: UpdateSubModuleLessonRequest) =>
+  http.put<UpdateSubModuleLessonResponse>(`/course-management/sub-module-lessons/${lessonId}`, data)
+
+export const softDeleteSubModuleLesson = (lessonId: number) =>
+  http.put<UpdateSubModuleLessonResponse>(`/course-management/sub-module-lessons/${lessonId}`, {
+    is_active: false,
+  })
+
 export const createSubCourseVideo = (data: CreateSubCourseVideoRequest) =>
   http.post("/course-management/sub-module-videos", {
     sub_module_id: data.sub_module_id ?? data.sub_course_id,
@@ -285,6 +440,43 @@ export const createPractice = (data: CreatePracticeRequest) =>
         .then(() => res)
     })
 
+export const createLesson = (data: {
+  sub_module_id: number
+  title: string
+  description?: string
+  intro_video_url?: string
+  persona?: string
+  status?: "DRAFT" | "PUBLISHED"
+  passing_score?: number
+  time_limit_minutes?: number
+  shuffle_questions?: boolean
+}) =>
+  http
+    .post<CreateQuestionSetResponse>("/question-sets", {
+      title: data.title,
+      set_type: "QUIZ",
+      owner_type: "SUB_MODULE",
+      owner_id: data.sub_module_id,
+      ...(data.description?.trim() ? { description: data.description.trim() } : {}),
+      ...(data.intro_video_url?.trim() ? { intro_video_url: data.intro_video_url.trim() } : {}),
+      ...(data.persona?.trim() ? { persona: data.persona.trim() } : {}),
+      ...(data.status ? { status: data.status } : {}),
+      ...(Number.isFinite(data.passing_score) ? { passing_score: data.passing_score } : {}),
+      ...(Number.isFinite(data.time_limit_minutes) ? { time_limit_minutes: data.time_limit_minutes } : {}),
+      ...(typeof data.shuffle_questions === "boolean" ? { shuffle_questions: data.shuffle_questions } : {}),
+    })
+    .then((res) => {
+      const questionSetID = res.data?.data?.id
+      if (!questionSetID) return res
+      return http
+        .post("/course-management/sub-module-lessons", {
+          sub_module_id: data.sub_module_id,
+          question_set_id: questionSetID,
+          intro_video_url: data.intro_video_url,
+        })
+        .then(() => res)
+    })
+
 export const updatePractice = (practiceId: number, data: UpdatePracticeRequest) =>
   http.put(`/course-management/practices/${practiceId}`, data)
 
@@ -506,186 +698,92 @@ export const getHumanLanguageLessonsByCourse = (courseId: number, cefr_level: st
     params: { cefr_level },
   })
 
-export const getHumanLanguageHierarchy = () =>
+export const getHumanLanguageSubCategories = () =>
-  http.get<GetHumanLanguageHierarchyResponse>("/course-management/hierarchy").then(async (res) => {
+  http.get<GetHumanLanguageSubCategoriesResponse>("/course-management/human-language/sub-categories")
-    const payload = res.data?.data as unknown
-    if (payload && typeof payload === "object" && !Array.isArray(payload) && "sub_categories" in payload) {
-      return res
-    }
 
-    const rows: UnifiedHierarchyRow[] = Array.isArray(payload) ? payload : []
+export const getCoursesBySubCategoryId = (subCategoryId: number) =>
-    const categoryMap = new Map<
+  http.get<GetSubCategoryCoursesResponse>(`/course-management/sub-categories/${subCategoryId}/courses`)
-      number,
-      {
-        category_id: number
-        category_name: string
-        sub_categories: Map<
-          number,
-          {
-            sub_category_id: number
-            sub_category_name: string
-            courses: Map<
-              number,
-              {
-                course_id: number
-                course_name: string
-              }
-            >
-          }
-        >
-      }
-    >()
 
-    rows.forEach((row) => {
+export const getSubModulesByModuleId = (moduleId: number) =>
-      const categoryId = Number(row.category_id)
+  http.get<GetSubModulesByModuleResponse>(`/course-management/modules/${moduleId}/sub-modules`)
-      if (!Number.isFinite(categoryId)) return
 
-      if (!categoryMap.has(categoryId)) {
+/**
-        categoryMap.set(categoryId, {
+ * Finds a sub-module under a course by walking levels → modules → sub-modules APIs.
-          category_id: categoryId,
+ * Use when the legacy hierarchy flatten (`getSubModulesByCourse`) does not include the row.
-          category_name: row.category_name ?? "",
+ */
-          sub_categories: new Map(),
+export async function resolveSubModuleForCourse(
-        })
+  courseId: number,
-      }
+  subModuleId: number,
-
+): Promise<SubCourse | null> {
-      if (!row.sub_category_id) return
+  try {
-      const subCategoryId = Number(row.sub_category_id)
+    const levelsRes = await getCourseLevelsForCourse(courseId)
-      if (!Number.isFinite(subCategoryId)) return
+    const levels = Array.isArray(levelsRes.data?.data?.levels) ? levelsRes.data.data.levels : []
-
+    const sortedLevels = [...levels].sort((a, b) => {
-      const categoryNode = categoryMap.get(categoryId)!
+      const o = (a.display_order ?? 0) - (b.display_order ?? 0)
-      if (!categoryNode.sub_categories.has(subCategoryId)) {
+      if (o !== 0) return o
-        categoryNode.sub_categories.set(subCategoryId, {
+      return String(a.cefr_level ?? "").localeCompare(String(b.cefr_level ?? ""))
-          sub_category_id: subCategoryId,
-          sub_category_name: row.sub_category_name ?? "",
-          courses: new Map(),
-        })
-      }
-
-      if (!row.course_id) return
-      const courseId = Number(row.course_id)
-      if (!Number.isFinite(courseId)) return
-
-      const subCategoryNode = categoryNode.sub_categories.get(subCategoryId)!
-      if (!subCategoryNode.courses.has(courseId)) {
-        subCategoryNode.courses.set(courseId, {
-          course_id: courseId,
-          course_name: row.course_title ?? "",
-        })
-      }
     })
 
-    const selectedCategory =
+    const modulesNested = await Promise.all(
-      Array.from(categoryMap.values()).find((c) => c.category_name.toLowerCase().includes("human")) ??
+      sortedLevels.map(async (level) => {
-      Array.from(categoryMap.values())[0]
+        const modsRes = await getModulesByLevel(level.id)
-
+        const rawMods = modsRes.data?.data?.modules
-    if (!selectedCategory) {
+        const modules = Array.isArray(rawMods) ? rawMods : []
-      return {
+        const sortedMods = [...modules].sort((a, b) => (a.display_order ?? 0) - (b.display_order ?? 0))
-        ...res,
+        return sortedMods.map((module) => ({ level, module }))
-        data: {
-          ...res.data,
-          data: {
-            category_id: 0,
-            category_name: "",
-            sub_categories: [],
-          },
-        },
-      } as unknown as { data: GetHumanLanguageHierarchyResponse }
-    }
-
-    const courses = Array.from(selectedCategory.sub_categories.values()).flatMap((sub) =>
-      Array.from(sub.courses.values()).map((course) => ({ sub_category_id: sub.sub_category_id, course })),
-    )
-
-    const hierarchyResponses = await Promise.all(
-      courses.map(({ course }) =>
-        http
-          .get(`/course-management/courses/${course.course_id}/hierarchy`)
-          .then((courseRes) => ({ course_id: course.course_id, rows: (courseRes.data?.data ?? []) as CourseHierarchyRow[] }))
-          .catch(() => ({ course_id: course.course_id, rows: [] as CourseHierarchyRow[] })),
-      ),
-    )
-
-    const hierarchyByCourse = new Map<number, CourseHierarchyRow[]>(
-      hierarchyResponses.map((h) => [h.course_id, h.rows]),
-    )
-
-    const subCategories = Array.from(selectedCategory.sub_categories.values()).map((sub) => ({
-      sub_category_id: sub.sub_category_id,
-      sub_category_name: sub.sub_category_name,
-      courses: Array.from(sub.courses.values()).map((course) => {
-        const levelMap = new Map<
-          string,
-          {
-            level: string
-            modules: Map<
-              number,
-              {
-                id: number
-                title: string
-                sub_modules: Map<number, { id: number; title: string; videos: []; practices: [] }>
-              }
-            >
-          }
-        >()
-
-        ;(hierarchyByCourse.get(course.course_id) ?? []).forEach((row) => {
-          if (!row.level_id || !row.cefr_level) return
-          const levelKey = String(row.cefr_level).toUpperCase()
-          if (!levelMap.has(levelKey)) {
-            levelMap.set(levelKey, { level: levelKey, modules: new Map() })
-          }
-
-          if (!row.module_id) return
-          const levelNode = levelMap.get(levelKey)!
-          const moduleId = Number(row.module_id)
-          if (!levelNode.modules.has(moduleId)) {
-            levelNode.modules.set(moduleId, {
-              id: moduleId,
-              title: row.module_title ?? "",
-              sub_modules: new Map(),
-            })
-          }
-
-          if (!row.sub_module_id) return
-          const moduleNode = levelNode.modules.get(moduleId)!
-          const subModuleId = Number(row.sub_module_id)
-          if (!moduleNode.sub_modules.has(subModuleId)) {
-            moduleNode.sub_modules.set(subModuleId, {
-              id: subModuleId,
-              title: row.sub_module_title ?? "",
-              videos: [],
-              practices: [],
-            })
-          }
-        })
-
-        return {
-          course_id: course.course_id,
-          course_name: course.course_name,
-          levels: Array.from(levelMap.values()).map((levelNode) => ({
-            level: levelNode.level,
-            modules: Array.from(levelNode.modules.values()).map((moduleNode) => ({
-              id: moduleNode.id,
-              title: moduleNode.title,
-              sub_modules: Array.from(moduleNode.sub_modules.values()),
-            })),
-          })),
-        }
       }),
-    }))
+    )
+    const modulePairs = modulesNested.flat()
 
-    return {
+    const bundles = await Promise.all(
-      ...res,
+      modulePairs.map(async ({ level, module }) => {
-      data: {
+        const subsRes = await getSubModulesByModuleId(module.id)
-        ...res.data,
+        const rawSubs = subsRes.data?.data?.sub_modules
-        data: {
+        const subs = Array.isArray(rawSubs) ? rawSubs : []
-          category_id: selectedCategory.category_id,
+        const sortedSubs = [...subs].sort((a, b) => (a.display_order ?? 0) - (b.display_order ?? 0))
-          category_name: selectedCategory.category_name,
+        return { level, module, subs: sortedSubs }
-          sub_categories: subCategories,
+      }),
-        },
+    )
-      },
+
-    } as unknown as { data: GetHumanLanguageHierarchyResponse }
+    for (const { level, module, subs } of bundles) {
-  })
+      const found = subs.find((s) => s.id === subModuleId)
+      if (found) {
+        return {
+          id: found.id,
+          course_id: courseId,
+          level_id: level.id,
+          module_id: module.id,
+          title: found.title,
+          description: found.description ?? "",
+          level: level.cefr_level,
+          cefr_level: level.cefr_level,
+          thumbnail: found.thumbnail ?? "",
+          display_order: found.display_order,
+          sub_level: level.cefr_level,
+          is_active: found.is_active,
+        }
+      }
+    }
+  } catch (e) {
+    console.error("resolveSubModuleForCourse failed:", e)
+  }
+  return null
+}
+
+export const getCourseLevelsForCourse = (courseId: number) =>
+  http.get<GetCourseLevelsForCourseResponse>(`/course-management/courses/${courseId}/levels`)
+
+export const getAllCourseLevels = () => http.get<GetCourseLevelsAllResponse>("/course-management/levels")
+
+export const getCourseLevelById = (levelId: number) =>
+  http.get<GetCourseLevelByIdResponse>(`/course-management/levels/${levelId}`)
+
+export const getHumanLanguageHierarchy = (options?: { cacheBust?: boolean }) =>
+  withSingleRetry(() =>
+    http.get<GetHumanLanguageHierarchyFlatResponse>("/course-management/human-language/hierarchy", {
+      params: options?.cacheBust ? { _t: Date.now() } : undefined,
+    }),
+  )
 
 export const createHumanLanguageLesson = (data: CreateHumanLanguageLessonRequest) =>
   http
@@ -714,6 +812,34 @@ export const createHumanLanguageLesson = (data: CreateHumanLanguageLessonRequest
       }),
     )
 
+export const createModuleInLevel = (
+  levelId: number,
+  title: string,
+  description: string,
+  displayOrder = 0,
+) =>
+  http.post("/course-management/modules", {
+    level_id: levelId,
+    title,
+    description,
+    display_order: displayOrder,
+    is_active: true,
+  })
+
+export const createSubModuleInModule = (
+  moduleId: number,
+  title: string,
+  description: string,
+  displayOrder = 0,
+) =>
+  http.post("/course-management/sub-modules", {
+    module_id: moduleId,
+    title,
+    description,
+    display_order: displayOrder,
+    is_active: true,
+  })
+
 export const getSubModuleEntryAssessment = (subModuleId: number) =>
   http.get<GetSubCourseEntryAssessmentResponse>(
     `/question-sets/sub-courses/${subModuleId}/entry-assessment`,

src/api/http.ts

@@ -12,6 +12,7 @@ let failedQueue: Array<{
   resolve: (token: string) => void;
   reject: (error: Error) => void;
 }> = [];
+const TOKEN_REFRESH_BUFFER_SECONDS = 120;
 
 const processQueue = (error: Error | null, token: string | null = null) => {
   failedQueue.forEach((prom) => {
@@ -32,23 +33,47 @@ const clearAuthAndRedirect = () => {
   window.location.href = "/login";
 };
 
-const refreshAccessToken = async (): Promise<string> => {
+const decodeJwtPayload = (token: string): Record<string, unknown> | null => {
-  const accessToken = localStorage.getItem("access_token");
+  try {
-  const refreshToken = localStorage.getItem("refresh_token");
+    const payloadPart = token.split(".")[1];
-  const role = localStorage.getItem("role");
+    if (!payloadPart) return null;
-  const memberId = localStorage.getItem("member_id");
+    const normalized = payloadPart.replace(/-/g, "+").replace(/_/g, "/");
+    const padded = normalized.padEnd(Math.ceil(normalized.length / 4) * 4, "=");
+    const json = atob(padded);
+    return JSON.parse(json) as Record<string, unknown>;
+  } catch {
+    return null;
+  }
+};
 
-  if (!refreshToken || !memberId) {
+const isAccessTokenExpiringSoon = (token: string) => {
+  const payload = decodeJwtPayload(token);
+  const exp = Number(payload?.exp);
+  if (!Number.isFinite(exp)) return true;
+  const nowSeconds = Math.floor(Date.now() / 1000);
+  return exp - nowSeconds <= TOKEN_REFRESH_BUFFER_SECONDS;
+};
+
+const isAuthEndpointRequest = (url?: string) => {
+  if (!url) return false;
+  return (
+    url.includes("/team/login") ||
+    url.includes("/team/google-login") ||
+    url.includes("/team/refresh")
+  );
+};
+
+const refreshAccessToken = async (): Promise<string> => {
+  const refreshToken = localStorage.getItem("refresh_token");
+
+  if (!refreshToken) {
     throw new Error("No refresh token available");
   }
 
   const response = await axios.post(
-    `${import.meta.env.VITE_API_BASE_URL}/auth/refresh`,
+    `${import.meta.env.VITE_API_BASE_URL}/team/refresh`,
     {
-      access_token: accessToken,
       refresh_token: refreshToken,
-      role: role || "admin",
-      member_id: Number(memberId),
     }
   );
 
@@ -65,9 +90,43 @@ const refreshAccessToken = async (): Promise<string> => {
   return newAccessToken;
 };
 
+const getValidAccessToken = async (forceRefresh = false): Promise<string> => {
+  const currentToken = localStorage.getItem("access_token");
+  if (!forceRefresh && currentToken && !isAccessTokenExpiringSoon(currentToken)) {
+    return currentToken;
+  }
+
+  if (isRefreshing) {
+    return new Promise((resolve, reject) => {
+      failedQueue.push({ resolve, reject });
+    });
+  }
+
+  isRefreshing = true;
+  try {
+    const newToken = await refreshAccessToken();
+    processQueue(null, newToken);
+    return newToken;
+  } catch (refreshError) {
+    processQueue(refreshError as Error, null);
+    clearAuthAndRedirect();
+    throw refreshError;
+  } finally {
+    isRefreshing = false;
+  }
+};
+
 // Attach access token to every request
-http.interceptors.request.use((config) => {
+http.interceptors.request.use(async (config) => {
-  const token = localStorage.getItem("access_token");
+  if (isAuthEndpointRequest(config.url)) {
+    return config;
+  }
+
+  let token = localStorage.getItem("access_token");
+  if (token && isAccessTokenExpiringSoon(token)) {
+    token = await getValidAccessToken();
+  }
+
   if (token) {
     config.headers.Authorization = `Bearer ${token}`;
   }
@@ -80,32 +139,19 @@ http.interceptors.response.use(
   async (error: AxiosError) => {
     const originalRequest = error.config as InternalAxiosRequestConfig & { _retry?: boolean };
 
-    if (error.response?.status === 401 && !originalRequest._retry) {
+    if (
-      if (isRefreshing) {
+      error.response?.status === 401 &&
-        return new Promise((resolve, reject) => {
+      !originalRequest._retry &&
-          failedQueue.push({ resolve, reject });
+      !isAuthEndpointRequest(originalRequest.url)
-        })
+    ) {
-          .then((token) => {
-            originalRequest.headers.Authorization = `Bearer ${token}`;
-            return http(originalRequest);
-          })
-          .catch((err) => Promise.reject(err));
-      }
-
       originalRequest._retry = true;
-      isRefreshing = true;
 
       try {
-        const newToken = await refreshAccessToken();
+        const newToken = await getValidAccessToken(true);
-        processQueue(null, newToken);
         originalRequest.headers.Authorization = `Bearer ${newToken}`;
         return http(originalRequest);
       } catch (refreshError) {
-        processQueue(refreshError as Error, null);
-        clearAuthAndRedirect();
         return Promise.reject(refreshError);
-      } finally {
-        isRefreshing = false;
       }
     }
 

src/api/rbac.api.ts

@@ -5,6 +5,7 @@ import type {
   GetRolesParams,
   CreateRoleRequest,
   CreateRoleResponse,
+  DeleteRoleResponse,
   SetRolePermissionsRequest,
   GetPermissionsResponse,
 } from "../types/rbac.types"
@@ -26,3 +27,6 @@ export const setRolePermissions = (roleId: number, data: SetRolePermissionsReque
 
 export const getAllPermissions = () =>
   http.get<GetPermissionsResponse>("/rbac/permissions")
+
+export const deleteRole = (roleId: number) =>
+  http.delete<DeleteRoleResponse>(`/rbac/roles/${roleId}`)

src/app/AppRoutes.tsx

@@ -10,8 +10,8 @@ import { ContentOverviewPage } from "../pages/content-management/ContentOverview
 import { CoursesPage } from "../pages/content-management/CoursesPage"
 import { PracticeQuestionsPage } from "../pages/content-management/PracticeQuestionsPage"
 import { AddNewPracticePage } from "../pages/content-management/AddNewPracticePage"
+import { AddNewLessonPage } from "../pages/content-management/AddNewLessonPage"
 import { SubModulesPage } from "../pages/content-management/SubCoursesPage"
-import { SubModuleContentPage } from "../pages/content-management/SubCourseContentPage"
 import { SpeakingPage } from "../pages/content-management/SpeakingPage"
 import { AddVideoPage } from "../pages/content-management/AddVideoPage"
 import { AddPracticePage } from "../pages/content-management/AddPracticePage"
@@ -31,8 +31,9 @@ import { PracticeDetailsPage } from "../pages/content-management/PracticeDetails
 import { PracticeMembersPage } from "../pages/content-management/PracticeMembersPage"
 import { QuestionsPage } from "../pages/content-management/QuestionsPage"
 import { AddQuestionPage } from "../pages/content-management/AddQuestionPage"
-import { HumanLanguagePage } from "../pages/content-management/HumanLanguagePage"
+import { HumanLanguageHierarchyPage } from "../pages/content-management/HumanLanguageHierarchyPage"
 import { HumanLanguageSubModulePage } from "../pages/content-management/HumanLanguageSubModulePage"
+import { SubCategoryCoursesPage } from "../pages/content-management/SubCategoryCoursesPage"
 import { UserLogPage } from "../pages/user-log/UserLogPage"
 import { IssuesPage } from "../pages/issues/IssuesPage"
 import { ProfilePage } from "../pages/ProfilePage"
@@ -78,30 +79,44 @@ export function AppRoutes() {
           <Route index element={<CourseCategoryPage />} />
           <Route path="courses" element={<AllCoursesPage />} />
           <Route path="flows" element={<CourseFlowBuilderPage />} />
-          <Route path="human-language" element={<HumanLanguagePage />} />
+          <Route path="human-language" element={<HumanLanguageHierarchyPage />} />
           <Route
             path="human-language/:categoryId/:courseId/sub-module/:subModuleId/add-practice"
             element={<AddNewPracticePage />}
           />
+          <Route
+            path="human-language/:categoryId/:courseId/sub-module/:subModuleId/add-lesson"
+            element={<AddNewLessonPage />}
+          />
           <Route
             path="human-language/:categoryId/:courseId/sub-module/:subModuleId/practices/:practiceId/questions"
             element={<PracticeQuestionsPage />}
           />
+          <Route
+            path="human-language/:categoryId/:courseId/level/:levelId/practices/:practiceId/questions"
+            element={<PracticeQuestionsPage />}
+          />
           <Route
             path="human-language/:categoryId/:courseId/sub-module/:subModuleId"
             element={<HumanLanguageSubModulePage />}
           />
           <Route path="category/:categoryId" element={<ContentOverviewPage />} />
+          <Route
+            path="category/:categoryId/sub-categories/:subCategoryId/courses"
+            element={<SubCategoryCoursesPage />}
+          />
           <Route path="category/:categoryId/courses" element={<CoursesPage />} />
           {/* Course → Sub-module → Lesson/Practice */}
           <Route path="category/:categoryId/courses/:courseId/sub-modules" element={<SubModulesPage />} />
-          <Route path="category/:categoryId/courses/:courseId/sub-modules/:subModuleId" element={<SubModuleContentPage />} />
+          <Route path="category/:categoryId/courses/:courseId/sub-modules/:subModuleId" element={<HumanLanguageSubModulePage />} />
           <Route path="category/:categoryId/courses/:courseId/sub-modules/:subModuleId/add-practice" element={<AddNewPracticePage />} />
+          <Route path="category/:categoryId/courses/:courseId/sub-modules/:subModuleId/add-lesson" element={<AddNewLessonPage />} />
           <Route path="category/:categoryId/courses/:courseId/sub-modules/:subModuleId/practices/:practiceId/questions" element={<PracticeQuestionsPage />} />
           {/* Legacy aliases */}
           <Route path="category/:categoryId/courses/:courseId/sub-courses" element={<SubModulesPage />} />
-          <Route path="category/:categoryId/courses/:courseId/sub-courses/:subModuleId" element={<SubModuleContentPage />} />
+          <Route path="category/:categoryId/courses/:courseId/sub-courses/:subModuleId" element={<HumanLanguageSubModulePage />} />
           <Route path="category/:categoryId/courses/:courseId/sub-courses/:subModuleId/add-practice" element={<AddNewPracticePage />} />
+          <Route path="category/:categoryId/courses/:courseId/sub-courses/:subModuleId/add-lesson" element={<AddNewLessonPage />} />
           <Route path="category/:categoryId/courses/:courseId/sub-courses/:subModuleId/practices/:practiceId/questions" element={<PracticeQuestionsPage />} />
           <Route path="category/:categoryId/courses/add-video" element={<AddVideoPage />} />
           <Route path="speaking" element={<SpeakingPage />} />

src/components/topbar/Topbar.tsx

@@ -45,7 +45,7 @@ export function Topbar({ onSidebarToggle }: TopbarProps) {
   }
 
   return (
-    <header className="sticky top-0 z-10 flex h-16 items-center justify-between gap-3 border-b bg-grayScale-50/85 px-4 backdrop-blur lg:justify-end lg:px-6">
+    <header className="sticky top-0 z-40 flex h-16 items-center justify-between gap-3 border-b bg-grayScale-50/85 px-4 backdrop-blur lg:justify-end lg:px-6">
       {/* Sidebar toggle */}
       <button
         type="button"

src/layouts/AppLayout.tsx

@@ -1,16 +1,18 @@
-import { useState, useCallback } from "react"
+import { useState, useCallback, useEffect, useMemo, useRef } from "react"
-import { Navigate, Outlet } from "react-router-dom"
+import { Navigate, Outlet, useLocation } from "react-router-dom"
 import { Sidebar } from "../components/sidebar/Sidebar"
 import { Topbar } from "../components/topbar/Topbar"
 
 export function AppLayout() {
   const [sidebarOpen, setSidebarOpen] = useState(false)
   const [sidebarCollapsed, setSidebarCollapsed] = useState(false)
+  const mainRef = useRef<HTMLElement | null>(null)
+  const previousRouteKeyRef = useRef<string>("")
+  const location = useLocation()
+  const scrollStoragePrefix = "app:scroll:"
+  const routeKey = useMemo(() => `${location.pathname}${location.search}`, [location.pathname, location.search])
 
   const token = localStorage.getItem("access_token")
-  if (!token) {
-    return <Navigate to="/login" replace />
-  }
 
   const handleSidebarToggle = useCallback(() => {
     setSidebarOpen((prev) => !prev)
@@ -20,6 +22,43 @@ export function AppLayout() {
     setSidebarOpen(false)
   }, [])
 
+  useEffect(() => {
+    const container = mainRef.current
+    if (!container) return
+
+    const saveScroll = (key: string) => {
+      sessionStorage.setItem(`${scrollStoragePrefix}${key}`, String(container.scrollTop || 0))
+    }
+
+    const previousKey = previousRouteKeyRef.current
+    if (previousKey && previousKey !== routeKey) {
+      saveScroll(previousKey)
+    }
+    previousRouteKeyRef.current = routeKey
+
+    const restoreRaw = sessionStorage.getItem(`${scrollStoragePrefix}${routeKey}`)
+    const restoreTop = restoreRaw ? Number(restoreRaw) : 0
+    const top = Number.isFinite(restoreTop) && restoreTop > 0 ? restoreTop : 0
+    requestAnimationFrame(() => {
+      container.scrollTo({ top, behavior: "auto" })
+    })
+
+    const onScroll = () => saveScroll(routeKey)
+    const onBeforeUnload = () => saveScroll(routeKey)
+    container.addEventListener("scroll", onScroll, { passive: true })
+    window.addEventListener("beforeunload", onBeforeUnload)
+
+    return () => {
+      saveScroll(routeKey)
+      container.removeEventListener("scroll", onScroll)
+      window.removeEventListener("beforeunload", onBeforeUnload)
+    }
+  }, [routeKey])
+
+  if (!token) {
+    return <Navigate to="/login" replace />
+  }
+
   return (
     <div className="flex min-h-screen bg-grayScale-100">
       <Sidebar
@@ -34,7 +73,7 @@ export function AppLayout() {
         }`}
       >
         <Topbar onSidebarToggle={handleSidebarToggle} />
-        <main className="min-w-0 flex-1 overflow-x-hidden overflow-y-auto px-3 pb-8 pt-4 sm:px-4 lg:px-6">
+        <main ref={mainRef} className="min-w-0 flex-1 overflow-x-hidden overflow-y-auto px-3 pb-8 pt-4 sm:px-4 lg:px-6">
           <Outlet />
         </main>
         <footer className="border-t bg-grayScale-50 px-4 py-3 lg:px-6">

src/pages/content-management/AddNewLessonPage.tsx

@@ -0,0 +1,650 @@
+import { useMemo, useState, type ChangeEvent } from "react"
+import { ArrowLeft, ArrowRight, Check, GripVertical, Plus, Rocket, Trash2, Upload } from "lucide-react"
+import { Link, useLocation, useNavigate, useParams } from "react-router-dom"
+import { toast } from "sonner"
+import { addQuestionToSet, createLesson, createQuestion } from "../../api/courses.api"
+import { uploadVideoFile } from "../../api/files.api"
+import { PracticeQuestionEditorFields } from "../../components/content-management/PracticeQuestionEditorFields"
+import { Button } from "../../components/ui/button"
+import { Card } from "../../components/ui/card"
+import { Input } from "../../components/ui/input"
+import { SpinnerIcon } from "../../components/ui/spinner-icon"
+import type { QuestionOption } from "../../types/course.types"
+
+type Step = 1 | 2 | 3 | 4
+type QuestionType = "MCQ" | "TRUE_FALSE" | "SHORT" | "AUDIO"
+type DifficultyLevel = "EASY" | "MEDIUM" | "HARD"
+type ResultStatus = "success" | "error"
+
+interface MCQOption {
+  text: string
+  isCorrect: boolean
+}
+
+interface Question {
+  id: string
+  questionText: string
+  questionType: QuestionType
+  difficultyLevel: DifficultyLevel
+  points: number
+  tips: string
+  explanation: string
+  options: MCQOption[]
+  voicePrompt: string
+  sampleAnswerVoicePrompt: string
+  audioCorrectAnswerText: string
+  shortAnswers: string[]
+  imageUrl: string
+}
+
+const STEPS = [
+  { number: 1, label: "Context" },
+  { number: 2, label: "Questions" },
+  { number: 3, label: "Review" },
+]
+
+function createEmptyQuestion(id: string): Question {
+  return {
+    id,
+    questionText: "",
+    questionType: "MCQ",
+    difficultyLevel: "EASY",
+    points: 1,
+    tips: "",
+    explanation: "",
+    options: [
+      { text: "", isCorrect: true },
+      { text: "", isCorrect: false },
+      { text: "", isCorrect: false },
+      { text: "", isCorrect: false },
+    ],
+    voicePrompt: "",
+    sampleAnswerVoicePrompt: "",
+    audioCorrectAnswerText: "",
+    shortAnswers: [],
+    imageUrl: "",
+  }
+}
+
+function introVideoUrlFromUploadResponse(data: { url?: string; embed_url?: string } | undefined): string | null {
+  if (!data) return null
+  const pageUrl = data.url?.trim()
+  const embedUrl = data.embed_url?.trim()
+  if (embedUrl) {
+    const hashFromUrl = pageUrl ? pageUrl.split("/").filter(Boolean).at(-1) : undefined
+    return hashFromUrl ? `${embedUrl}?h=${hashFromUrl}` : embedUrl
+  }
+  return pageUrl || null
+}
+
+function toVimeoEmbedUrl(rawUrl: string): string | null {
+  try {
+    const parsed = new URL(rawUrl.trim())
+    const host = parsed.hostname.toLowerCase()
+    if (!host.includes("vimeo.com")) return null
+    if (host.includes("player.vimeo.com") && parsed.pathname.includes("/video/")) return parsed.toString()
+    const segments = parsed.pathname.split("/").filter(Boolean)
+    const videoId = segments.find((segment) => /^\d+$/.test(segment))
+    if (!videoId) return null
+    const hash = parsed.searchParams.get("h")
+    return hash
+      ? `https://player.vimeo.com/video/${videoId}?h=${encodeURIComponent(hash)}`
+      : `https://player.vimeo.com/video/${videoId}`
+  } catch {
+    return null
+  }
+}
+
+function isDirectVideoFile(url: string): boolean {
+  const clean = url.split("?")[0].toLowerCase()
+  return /\.(mp4|webm|ogg|mov|m4v)$/.test(clean)
+}
+
+function questionTypeLabel(type: QuestionType): string {
+  if (type === "TRUE_FALSE") return "True/False"
+  if (type === "SHORT") return "Short Answer"
+  if (type === "AUDIO") return "Audio"
+  return "Multiple Choice"
+}
+
+export function AddNewLessonPage() {
+  const { categoryId, courseId, subModuleId } = useParams()
+  const navigate = useNavigate()
+  const location = useLocation()
+
+  const backTo = useMemo(() => {
+    if (location.pathname.includes("/content/human-language/") && location.pathname.includes("/sub-module/")) {
+      return `/content/human-language/${categoryId}/${courseId}/sub-module/${subModuleId}`
+    }
+    return `/content/category/${categoryId}/courses/${courseId}/sub-modules/${subModuleId}`
+  }, [categoryId, courseId, subModuleId, location.pathname])
+
+  const [currentStep, setCurrentStep] = useState<Step>(1)
+  const [saving, setSaving] = useState(false)
+  const [resultStatus, setResultStatus] = useState<ResultStatus | null>(null)
+  const [resultMessage, setResultMessage] = useState("")
+  const [lastSavedStatus, setLastSavedStatus] = useState<"DRAFT" | "PUBLISHED" | null>(null)
+
+  const [lessonTitle, setLessonTitle] = useState("")
+  const [lessonDescription, setLessonDescription] = useState("")
+  const [introVideoUrl, setIntroVideoUrl] = useState("")
+  const [uploadingIntroVideo, setUploadingIntroVideo] = useState(false)
+  const [questions, setQuestions] = useState<Question[]>([createEmptyQuestion("1")])
+
+  const handleNext = () => setCurrentStep((s) => (s < 3 ? ((s + 1) as Step) : s))
+  const handleBack = () => setCurrentStep((s) => (s > 1 ? ((s - 1) as Step) : s))
+
+  const handleIntroVideoFileChange = async (event: ChangeEvent<HTMLInputElement>) => {
+    const file = event.target.files?.[0]
+    event.target.value = ""
+    if (!file) return
+    setUploadingIntroVideo(true)
+    try {
+      const uploadRes = await uploadVideoFile(file, {
+        title: lessonTitle.trim() || file.name.replace(/\.[^.]+$/, "") || "Lesson intro",
+        description: lessonDescription.trim() || undefined,
+      })
+      const finalUrl = introVideoUrlFromUploadResponse(uploadRes.data?.data)
+      if (!finalUrl) throw new Error("Missing uploaded video url")
+      setIntroVideoUrl(finalUrl)
+      toast.success("Intro video uploaded")
+    } catch (error) {
+      console.error("Failed to upload lesson intro video:", error)
+      toast.error("Failed to upload intro video")
+    } finally {
+      setUploadingIntroVideo(false)
+    }
+  }
+
+  const handleIntroVideoUrlBlur = async () => {
+    const source = introVideoUrl.trim()
+    if (!source || !/^https?:\/\//i.test(source)) return
+    const vimeoEmbed = toVimeoEmbedUrl(source)
+    if (vimeoEmbed) {
+      setIntroVideoUrl(vimeoEmbed)
+      return
+    }
+    if (isDirectVideoFile(source)) {
+      setIntroVideoUrl(source)
+      return
+    }
+
+    // For non-direct URLs, automatically try server-side import via /files/upload.
+    setUploadingIntroVideo(true)
+    try {
+      const uploadRes = await uploadVideoFile(source, {
+        title: lessonTitle.trim() || "Lesson intro",
+        description: lessonDescription.trim() || undefined,
+      })
+      const finalUrl = introVideoUrlFromUploadResponse(uploadRes.data?.data)
+      if (!finalUrl) throw new Error("Missing uploaded video url")
+      setIntroVideoUrl(finalUrl)
+      toast.success("Intro video URL imported")
+    } catch (error) {
+      console.error("Failed to import intro video URL:", error)
+      toast.error("Failed to import intro video URL")
+    } finally {
+      setUploadingIntroVideo(false)
+    }
+  }
+
+  const introVideoPreview = useMemo(() => {
+    const raw = introVideoUrl.trim()
+    if (!raw) return null
+    const vimeoEmbedUrl = toVimeoEmbedUrl(raw)
+    if (vimeoEmbedUrl) return { kind: "vimeo" as const, url: vimeoEmbedUrl }
+    if (isDirectVideoFile(raw)) return { kind: "video" as const, url: raw }
+    return null
+  }, [introVideoUrl])
+
+  const reviewQuestions = useMemo(() => questions, [questions])
+
+  const addQuestion = () => setQuestions((prev) => [...prev, createEmptyQuestion(String(Date.now()))])
+  const removeQuestion = (id: string) => setQuestions((prev) => (prev.length > 1 ? prev.filter((q) => q.id !== id) : prev))
+  const updateQuestion = (id: string, updates: Partial<Question>) =>
+    setQuestions((prev) => prev.map((q) => (q.id === id ? { ...q, ...updates } : q)))
+
+  const saveLesson = async (status: "DRAFT" | "PUBLISHED") => {
+    if (!subModuleId) {
+      toast.error("Missing sub-module id")
+      return
+    }
+    setSaving(true)
+    try {
+      const lessonRes = await createLesson({
+        sub_module_id: Number(subModuleId),
+        title: lessonTitle.trim() || "Untitled Lesson",
+        description: lessonDescription.trim() || undefined,
+        intro_video_url: introVideoUrl.trim() || undefined,
+        status,
+      })
+
+      const questionSetId = lessonRes.data?.data?.id
+      if (questionSetId) {
+        for (let i = 0; i < questions.length; i++) {
+          const q = questions[i]
+          if (!q.questionText.trim()) continue
+          const options: QuestionOption[] =
+            q.questionType === "MCQ"
+              ? q.options.map((opt, idx) => ({
+                  option_order: idx + 1,
+                  option_text: opt.text,
+                  is_correct: opt.isCorrect,
+                }))
+              : []
+
+          const qRes = await createQuestion({
+            question_text: q.questionText,
+            question_type: q.questionType,
+            difficulty_level: q.difficultyLevel,
+            points: q.points,
+            tips: q.tips || undefined,
+            explanation: q.explanation || undefined,
+            status: "PUBLISHED",
+            options: options.length > 0 ? options : undefined,
+            voice_prompt: q.voicePrompt || undefined,
+            sample_answer_voice_prompt: q.sampleAnswerVoicePrompt || undefined,
+            audio_correct_answer_text: q.audioCorrectAnswerText || undefined,
+            image_url: q.imageUrl.trim() || undefined,
+            short_answers: q.shortAnswers.length > 0 ? q.shortAnswers : undefined,
+          })
+          const questionId = qRes.data?.data?.id
+          if (questionId) {
+            await addQuestionToSet(questionSetId, { question_id: questionId, display_order: i + 1 })
+          }
+        }
+      }
+
+      setResultStatus("success")
+      setResultMessage(status === "PUBLISHED" ? "Lesson published successfully." : "Lesson saved as draft.")
+      setLastSavedStatus(status)
+      setCurrentStep(4)
+    } catch (error) {
+      console.error("Failed to save lesson:", error)
+      setResultStatus("error")
+      setResultMessage(error instanceof Error ? error.message : "Failed to save lesson")
+      setLastSavedStatus(null)
+      setCurrentStep(4)
+    } finally {
+      setSaving(false)
+    }
+  }
+
+  return (
+    <div className="mx-auto w-full max-w-7xl px-4 pb-12 sm:px-6 lg:px-8">
+      <div className="space-y-5 sm:space-y-6">
+        {currentStep !== 4 ? (
+          <>
+            <Link
+              to={backTo}
+              className="group inline-flex items-center gap-2 rounded-lg px-3 py-1.5 text-sm font-medium text-grayScale-600 transition-colors hover:bg-brand-50 hover:text-brand-600"
+            >
+              <ArrowLeft className="h-4 w-4 transition-transform group-hover:-translate-x-0.5" />
+              Back to Sub-course
+            </Link>
+            <div className="border-b border-grayScale-100 pb-6 sm:pb-8">
+              <h1 className="text-2xl font-bold tracking-tight text-grayScale-900 sm:text-3xl">Add New Lesson</h1>
+              <p className="mt-2 max-w-3xl text-sm leading-relaxed text-grayScale-500 sm:text-[15px]">
+                Create a lesson backed by `question_sets` and attach it through `sub_module_lessons`.
+              </p>
+            </div>
+            <div className="flex items-center justify-center rounded-2xl border border-grayScale-100 bg-grayScale-50/40 px-3 py-4 sm:px-6 sm:py-5">
+              {STEPS.map((step, index) => (
+                <div key={step.number} className="flex items-center">
+                  <div className="flex flex-col items-center">
+                    <div
+                      className={`flex h-9 w-9 items-center justify-center rounded-full text-xs font-semibold shadow-sm transition-all duration-300 sm:h-10 sm:w-10 sm:text-sm ${
+                        currentStep === step.number
+                          ? "bg-brand-500 text-white ring-4 ring-brand-100"
+                          : currentStep > step.number
+                            ? "bg-brand-500 text-white"
+                            : "border-2 border-grayScale-300 bg-white text-grayScale-400"
+                      }`}
+                    >
+                      {currentStep > step.number ? <Check className="h-4 w-4" /> : step.number}
+                    </div>
+                    <span className="mt-2 text-xs font-semibold text-grayScale-500">{step.label}</span>
+                  </div>
+                  {index < STEPS.length - 1 ? (
+                    <div className={`mx-4 h-0.5 w-20 ${currentStep > step.number ? "bg-brand-500" : "bg-grayScale-200"}`} />
+                  ) : null}
+                </div>
+              ))}
+            </div>
+          </>
+        ) : null}
+
+        {currentStep === 1 ? (
+          <Card className="overflow-hidden border-grayScale-200/80 shadow-sm">
+            <div className="border-b border-grayScale-100 bg-gradient-to-r from-grayScale-50/80 to-white px-5 py-5 sm:px-8 sm:py-6">
+              <h2 className="text-lg font-semibold tracking-tight text-grayScale-900 sm:text-xl">Step 1: Context</h2>
+              <p className="mt-1.5 max-w-3xl text-sm leading-relaxed text-grayScale-500">
+                Define lesson metadata that will be stored in the linked question set.
+              </p>
+            </div>
+            <div className="p-5 sm:p-8 lg:p-10">
+            <div className="mt-5 grid gap-8 lg:grid-cols-12">
+              <div className="space-y-4 lg:col-span-7">
+              <div className="space-y-2">
+                <label className="text-sm font-medium text-grayScale-700">Lesson title</label>
+                <Input
+                  value={lessonTitle}
+                  onChange={(e) => setLessonTitle(e.target.value)}
+                  placeholder="Enter lesson title"
+                  className="h-11"
+                />
+              </div>
+              <div className="space-y-2">
+                <label className="text-sm font-medium text-grayScale-700">Description</label>
+                <textarea
+                  value={lessonDescription}
+                  onChange={(e) => setLessonDescription(e.target.value)}
+                  className="min-h-[96px] w-full rounded-lg border border-grayScale-200 px-3 py-2.5 text-sm transition-colors focus:border-grayScale-400 focus:outline-none focus:ring-2 focus:ring-grayScale-100"
+                  placeholder="Enter lesson description"
+                />
+              </div>
+              <div className="space-y-2">
+                <label className="text-sm font-medium text-grayScale-700">Intro video URL (optional)</label>
+                <Input
+                  value={introVideoUrl}
+                  onChange={(e) => setIntroVideoUrl(e.target.value)}
+                  onBlur={() => void handleIntroVideoUrlBlur()}
+                  placeholder="https://..."
+                  type="url"
+                  inputMode="url"
+                  autoComplete="off"
+                  className="font-mono text-[13px]"
+                />
+                <div className="flex flex-wrap items-center gap-2">
+                  <label className="inline-flex cursor-pointer items-center gap-2 rounded-md border border-grayScale-200 px-3 py-2 text-xs text-grayScale-700 hover:bg-grayScale-50">
+                    {uploadingIntroVideo ? <SpinnerIcon className="h-4 w-4" alt="" /> : <Upload className="h-4 w-4" />}
+                    {uploadingIntroVideo ? "Uploading..." : "Upload video from computer"}
+                    <input
+                      type="file"
+                      accept="video/*"
+                      className="hidden"
+                      onChange={handleIntroVideoFileChange}
+                      disabled={uploadingIntroVideo}
+                    />
+                  </label>
+                  {introVideoUrl.trim() ? (
+                    <Button type="button" variant="ghost" size="sm" onClick={() => setIntroVideoUrl("")}>
+                      Clear URL
+                    </Button>
+                  ) : null}
+                </div>
+                {introVideoPreview ? (
+                  <div className="rounded-xl border border-grayScale-200 bg-grayScale-50/40 p-3">
+                    <p className="mb-2 text-xs font-medium text-grayScale-500">Preview</p>
+                    {introVideoPreview.kind === "vimeo" ? (
+                      <div className="overflow-hidden rounded-lg border border-grayScale-200 bg-black">
+                        <iframe
+                          src={introVideoPreview.url}
+                          title="Intro video preview"
+                          className="aspect-video w-full"
+                          allow="autoplay; fullscreen; picture-in-picture"
+                          allowFullScreen
+                        />
+                      </div>
+                    ) : (
+                      <video
+                        controls
+                        src={introVideoPreview.url}
+                        className="aspect-video w-full rounded-lg border border-grayScale-200 bg-black"
+                      />
+                    )}
+                  </div>
+                ) : null}
+              </div>
+              </div>
+              <aside className="space-y-4 lg:col-span-5">
+                <div className="rounded-xl border border-grayScale-200 bg-grayScale-50/40 p-5 shadow-sm">
+                  <h3 className="text-xs font-semibold uppercase tracking-wider text-grayScale-500">Lesson schema mapping</h3>
+                  <div className="mt-3 space-y-2 text-sm text-grayScale-700">
+                    <p>
+                      <span className="font-medium">question_sets.title</span> ← Lesson title
+                    </p>
+                    <p>
+                      <span className="font-medium">question_sets.description</span> ← Description
+                    </p>
+                    <p>
+                      <span className="font-medium">question_sets.set_type</span> = QUIZ
+                    </p>
+                    <p>
+                      <span className="font-medium">sub_module_lessons.intro_video_url</span> ← Intro URL
+                    </p>
+                  </div>
+                </div>
+              </aside>
+            </div>
+            </div>
+            <div className="flex flex-col-reverse items-stretch justify-between gap-3 border-t border-grayScale-100 bg-grayScale-50/30 px-5 py-4 sm:flex-row sm:items-center sm:px-8 sm:py-5">
+              <Button variant="ghost" onClick={() => navigate(backTo)} className="sm:w-auto">
+                Cancel
+              </Button>
+              <Button onClick={handleNext}>
+                Next: Questions
+                <ArrowRight className="ml-2 h-4 w-4" />
+              </Button>
+            </div>
+          </Card>
+        ) : null}
+
+        {currentStep === 2 ? (
+          <div className="space-y-5">
+            {questions.map((question, index) => (
+              <Card key={question.id} className="border border-grayScale-200/90 border-l-4 border-l-grayScale-700 p-5 shadow-sm">
+                <div className="mb-4 flex items-center justify-between">
+                  <div className="flex items-center gap-2">
+                    <GripVertical className="h-4 w-4 text-grayScale-400" />
+                    <span className="font-semibold">Question {index + 1}</span>
+                  </div>
+                  <button type="button" onClick={() => removeQuestion(question.id)} className="text-grayScale-400 hover:text-red-500">
+                    <Trash2 className="h-4 w-4" />
+                  </button>
+                </div>
+                <PracticeQuestionEditorFields
+                  value={{
+                    questionText: question.questionText,
+                    questionType: question.questionType,
+                    difficultyLevel: question.difficultyLevel,
+                    points: question.points,
+                    tips: question.tips,
+                    explanation: question.explanation,
+                    options: question.options,
+                    voicePrompt: question.voicePrompt,
+                    sampleAnswerVoicePrompt: question.sampleAnswerVoicePrompt,
+                    audioCorrectAnswerText: question.audioCorrectAnswerText,
+                    shortAnswer: question.shortAnswers[0] ?? "",
+                    imageUrl: question.imageUrl,
+                  }}
+                  onChange={(next) =>
+                    updateQuestion(question.id, {
+                      questionText: next.questionText,
+                      questionType: next.questionType as QuestionType,
+                      difficultyLevel: next.difficultyLevel as DifficultyLevel,
+                      points: next.points,
+                      tips: next.tips,
+                      explanation: next.explanation,
+                      options: next.options,
+                      voicePrompt: next.voicePrompt,
+                      sampleAnswerVoicePrompt: next.sampleAnswerVoicePrompt,
+                      audioCorrectAnswerText: next.audioCorrectAnswerText,
+                      shortAnswers: next.shortAnswer.trim() ? [next.shortAnswer.trim()] : [],
+                      imageUrl: next.imageUrl,
+                    })
+                  }
+                  mediaBusy={saving}
+                />
+              </Card>
+            ))}
+            <Button variant="outline" onClick={addQuestion} className="w-full border-dashed">
+              <Plus className="mr-2 h-4 w-4" />
+              Add another question
+            </Button>
+            <div className="flex items-center justify-between rounded-2xl border border-grayScale-200/80 bg-grayScale-50/30 px-4 py-4 sm:px-6 sm:py-5">
+              <Button variant="outline" onClick={handleBack}>
+                Back
+              </Button>
+              <Button onClick={handleNext}>
+                Next: Review
+                <ArrowRight className="ml-2 h-4 w-4" />
+              </Button>
+            </div>
+          </div>
+        ) : null}
+
+        {currentStep === 3 ? (
+          <Card className="overflow-hidden border-grayScale-200/80 shadow-sm">
+            <div className="border-b border-grayScale-100 bg-gradient-to-r from-grayScale-50/80 to-white px-5 py-5 sm:px-8 sm:py-6">
+              <h2 className="text-lg font-semibold tracking-tight text-grayScale-900 sm:text-xl">Step 3: Review & publish</h2>
+              <p className="mt-1.5 text-sm text-grayScale-500">Confirm lesson details and questions before saving or publishing.</p>
+            </div>
+            <div className="space-y-4 p-5 sm:p-8">
+              <div className="grid gap-4 lg:grid-cols-2">
+                <div className="overflow-hidden rounded-2xl border border-grayScale-200 bg-white">
+                  <div className="flex items-center justify-between border-b border-grayScale-100 px-4 py-3">
+                    <h3 className="text-base font-semibold text-grayScale-900">Basic Information</h3>
+                    <button
+                      type="button"
+                      className="text-sm font-medium text-brand-500 hover:text-brand-600"
+                      onClick={() => setCurrentStep(1)}
+                    >
+                      Edit
+                    </button>
+                  </div>
+                  <div className="divide-y divide-grayScale-100">
+                    <div className="flex items-center justify-between px-4 py-3 text-sm">
+                      <span className="text-grayScale-500">Title</span>
+                      <span className="font-medium text-grayScale-800">{lessonTitle || "Untitled Lesson"}</span>
+                    </div>
+                    <div className="flex items-center justify-between px-4 py-3 text-sm">
+                      <span className="text-grayScale-500">Description</span>
+                      <span className="max-w-[55%] truncate text-right font-medium text-grayScale-800">
+                        {lessonDescription || "—"}
+                      </span>
+                    </div>
+                    <div className="flex items-center justify-between px-4 py-3 text-sm">
+                      <span className="text-grayScale-500">Intro video URL</span>
+                      <span className="max-w-[55%] truncate text-right font-medium text-grayScale-800">{introVideoUrl || "—"}</span>
+                    </div>
+                    <div className="flex items-center justify-between px-4 py-3 text-sm">
+                      <span className="text-grayScale-500">Sub-module</span>
+                      <span className="font-medium text-grayScale-800">{subModuleId ?? "—"}</span>
+                    </div>
+                  </div>
+                </div>
+
+                <div className="overflow-hidden rounded-2xl border border-grayScale-200 bg-white">
+                  <div className="flex items-center justify-between border-b border-grayScale-100 px-4 py-3">
+                    <h3 className="text-base font-semibold text-grayScale-900">
+                      Questions
+                      <span className="ml-2 rounded-full bg-brand-100 px-2 py-0.5 text-xs font-semibold text-brand-700">
+                        {reviewQuestions.length}
+                      </span>
+                    </h3>
+                    <button
+                      type="button"
+                      className="text-sm font-medium text-brand-500 hover:text-brand-600"
+                      onClick={() => setCurrentStep(2)}
+                    >
+                      Edit
+                    </button>
+                  </div>
+                  <div className="space-y-3 p-3">
+                    {reviewQuestions.length === 0 ? (
+                      <div className="rounded-xl border border-dashed border-grayScale-200 bg-grayScale-50/50 p-4 text-sm text-grayScale-500">
+                        No question content added yet.
+                      </div>
+                    ) : (
+                      reviewQuestions.map((question, idx) => (
+                        <div key={question.id} className="rounded-xl border border-grayScale-200 bg-grayScale-50/35 p-3">
+                          <div className="mb-2 flex items-center gap-2">
+                            <span className="inline-flex h-5 min-w-5 items-center justify-center rounded-full bg-brand-100 px-1.5 text-[11px] font-semibold text-brand-700">
+                              {idx + 1}
+                            </span>
+                            <span className="rounded-md bg-indigo-50 px-2 py-0.5 text-[11px] font-semibold text-indigo-700">
+                              {questionTypeLabel(question.questionType)}
+                            </span>
+                            <span className="rounded-md bg-grayScale-100 px-2 py-0.5 text-[11px] font-semibold text-grayScale-600">
+                              {question.difficultyLevel}
+                            </span>
+                            <span className="text-[11px] font-semibold text-grayScale-500">{question.points} pt</span>
+                          </div>
+                          <p className="mb-2 line-clamp-2 text-sm font-medium text-grayScale-800">
+                            {question.questionText.trim() || `Question ${idx + 1}`}
+                          </p>
+                          {question.questionType === "MCQ" ? (
+                            <div className="space-y-1">
+                              {question.options.map((option, optionIdx) => (
+                                <div
+                                  key={`${question.id}-option-${optionIdx}`}
+                                  className={`rounded px-2 py-1 text-xs ${
+                                    option.isCorrect
+                                      ? "bg-green-50 font-medium text-green-700"
+                                      : "text-grayScale-500"
+                                  }`}
+                                >
+                                  {option.text || `Option ${optionIdx + 1}`}
+                                </div>
+                              ))}
+                            </div>
+                          ) : null}
+                        </div>
+                      ))
+                    )}
+                  </div>
+                </div>
+              </div>
+            </div>
+            <div className="flex items-center justify-between border-t border-grayScale-100 bg-grayScale-50/30 px-5 py-4 sm:px-8 sm:py-5">
+              <Button variant="outline" onClick={handleBack}>
+                Back
+              </Button>
+              <div className="flex gap-3">
+                <Button variant="outline" onClick={() => void saveLesson("DRAFT")} disabled={saving}>
+                  {saving ? "Saving..." : "Save as Draft"}
+                </Button>
+                <Button onClick={() => void saveLesson("PUBLISHED")} disabled={saving}>
+                  <Rocket className="mr-2 h-4 w-4" />
+                  {saving ? "Publishing..." : "Publish Now"}
+                </Button>
+              </div>
+            </div>
+          </Card>
+        ) : null}
+
+        {currentStep === 4 && resultStatus ? (
+          <div className="mx-auto flex max-w-xl flex-col items-center py-16 text-center">
+            <div className={`mb-5 grid h-24 w-24 place-items-center rounded-full ${resultStatus === "success" ? "bg-gradient-to-br from-brand-200 to-brand-400" : "bg-gradient-to-br from-red-200 to-red-400"}`}>
+              <Check className="h-10 w-10 text-white" />
+            </div>
+            <h2 className="text-4xl font-bold tracking-tight text-grayScale-900">
+              {resultStatus === "success" ? "Lesson Published Successfully!" : "Lesson save failed"}
+            </h2>
+            <p className="mt-3 text-sm text-grayScale-500">{resultStatus === "success" ? "Your lesson is now active." : resultMessage}</p>
+            <div className="mt-8 w-full space-y-3">
+              <Button
+                className="h-11 w-full text-base"
+                onClick={() =>
+                  navigate(lastSavedStatus === "PUBLISHED" ? "/content/human-language" : backTo)
+                }
+              >
+                Go back to Course
+              </Button>
+              {resultStatus === "success" ? (
+                <Button variant="outline" className="h-11 w-full text-base" onClick={() => navigate(0)}>
+                  Add Another Lesson
+                </Button>
+              ) : (
+                <Button variant="outline" className="h-11 w-full text-base" onClick={() => setCurrentStep(3)}>
+                  Back to Review
+                </Button>
+              )}
+            </div>
+          </div>
+        ) : null}
+      </div>
+    </div>
+  )
+}

src/pages/content-management/AddNewPracticePage.tsx

@@ -1,6 +1,6 @@
 import { useMemo, useRef, useState, type ChangeEvent } from "react"
 import { Link, useLocation, useParams, useNavigate } from "react-router-dom"
-import { ArrowLeft, ArrowRight, ChevronDown, Grid3X3, Check, Plus, Trash2, GripVertical, Edit, Rocket, Loader2, Upload } from "lucide-react"
+import { ArrowLeft, ArrowRight, ChevronDown, Grid3X3, Check, Plus, Trash2, GripVertical, Edit, Rocket, Upload } from "lucide-react"
 import { toast } from "sonner"
 import { Card } from "../../components/ui/card"
 import { Button } from "../../components/ui/button"
@@ -9,6 +9,7 @@ import { PracticeQuestionEditorFields } from "../../components/content-managemen
 import { createQuestionSet, createQuestion, addQuestionToSet } from "../../api/courses.api"
 import { uploadVideoFile } from "../../api/files.api"
 import { Select } from "../../components/ui/select"
+import { SpinnerIcon } from "../../components/ui/spinner-icon"
 import type { QuestionOption } from "../../types/course.types"
 
 type Step = 1 | 2 | 3 | 4 | 5
@@ -526,7 +527,7 @@ export function AddNewPracticePage() {
                       className="gap-1.5"
                     >
                       {uploadingIntroVideo ? (
-                        <Loader2 className="h-4 w-4 animate-spin" />
+                        <SpinnerIcon className="h-4 w-4" alt="" />
                       ) : (
                         <Upload className="h-4 w-4" />
                       )}
@@ -541,7 +542,7 @@ export function AddNewPracticePage() {
                     >
                       {importingIntroVideoUrl ? (
                         <>
-                          <Loader2 className="mr-1.5 h-4 w-4 animate-spin" />
+                          <SpinnerIcon className="mr-1.5 h-4 w-4" alt="" />
                           Importing URL…
                         </>
                       ) : (

src/pages/content-management/CourseCategoryPage.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState } from "react"
 import { Link } from "react-router-dom"
-import { FolderOpen, RefreshCw, BookOpen, Plus } from "lucide-react"
+import { FolderOpen, RefreshCw, BookOpen, Plus, Trash2 } from "lucide-react"
 import spinnerSrc from "../../assets/Circular-indeterminate progress indicator.svg"
 import alertSrc from "../../assets/Alert.svg"
 import { Card, CardContent, CardHeader, CardTitle } from "../../components/ui/card"
@@ -11,10 +11,11 @@ import {
   Dialog,
   DialogContent,
   DialogDescription,
+  DialogFooter,
   DialogHeader,
   DialogTitle,
 } from "../../components/ui/dialog"
-import { getCourseCategories, createCourseCategory } from "../../api/courses.api"
+import { getCourseCategories, createCourseCategory, deleteCourseCategory } from "../../api/courses.api"
 import type { CourseCategory } from "../../types/course.types"
 import { toast } from "sonner"
 
@@ -29,6 +30,8 @@ export function CourseCategoryPage() {
   const [newSubCategoryName, setNewSubCategoryName] = useState("")
   const [pendingSubCategories, setPendingSubCategories] = useState<string[]>([])
   const [searchQuery, setSearchQuery] = useState("")
+  const [deleteTarget, setDeleteTarget] = useState<CourseCategory | null>(null)
+  const [deleting, setDeleting] = useState(false)
 
   const fetchCategories = async () => {
     setLoading(true)
@@ -164,12 +167,26 @@ export function CourseCategoryPage() {
                 </CardHeader>
 
                 <CardContent>
-                  <span className="inline-flex items-center gap-1.5 text-sm font-medium text-brand-500 transition-colors group-hover:text-brand-600">
+                  <div className="flex items-center justify-between gap-2">
-                    View Sub-categories
+                    <span className="inline-flex items-center gap-1.5 text-sm font-medium text-brand-500 transition-colors group-hover:text-brand-600">
-                    <span className="inline-block transition-transform duration-300 group-hover:translate-x-1">
+                      View Sub-categories
-                      →
+                      <span className="inline-block transition-transform duration-300 group-hover:translate-x-1">
+                        →
+                      </span>
                     </span>
-                  </span>
+                    <button
+                      type="button"
+                      className="inline-flex h-8 w-8 items-center justify-center rounded-md border border-red-200 bg-white text-red-500 hover:bg-red-50"
+                      onClick={(e) => {
+                        e.preventDefault()
+                        e.stopPropagation()
+                        setDeleteTarget(category)
+                      }}
+                      aria-label={`Delete category ${category.name}`}
+                    >
+                      <Trash2 className="h-4 w-4" />
+                    </button>
+                  </div>
                 </CardContent>
               </Card>
             </Link>
@@ -335,7 +352,7 @@ export function CourseCategoryPage() {
                   if (createdCategoryId && pendingSubCategories.length > 0) {
                     await Promise.all(
                       pendingSubCategories.map((subName) =>
-                        createCourseCategory({ name: subName }),
+                        createCourseCategory({ name: subName, parent_id: createdCategoryId }),
                       ),
                     )
                   }
@@ -371,6 +388,46 @@ export function CourseCategoryPage() {
           </div>
         </DialogContent>
       </Dialog>
+
+      <Dialog open={deleteTarget !== null} onOpenChange={(open) => !open && setDeleteTarget(null)}>
+        <DialogContent className="max-w-md">
+          <DialogHeader>
+            <DialogTitle>Delete category?</DialogTitle>
+            <DialogDescription>
+              {deleteTarget
+                ? `This will permanently delete "${deleteTarget.name}" and all linked sub-categories/courses.`
+                : ""}
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button type="button" variant="outline" onClick={() => setDeleteTarget(null)} disabled={deleting}>
+              Cancel
+            </Button>
+            <Button
+              type="button"
+              className="bg-red-600 text-white hover:bg-red-700"
+              disabled={deleting}
+              onClick={async () => {
+                if (!deleteTarget) return
+                setDeleting(true)
+                try {
+                  await deleteCourseCategory(deleteTarget.id)
+                  toast.success("Category deleted")
+                  setDeleteTarget(null)
+                  await fetchCategories()
+                } catch (err: any) {
+                  const message = err?.response?.data?.message || "Failed to delete category."
+                  toast.error("Could not delete category", { description: message })
+                } finally {
+                  setDeleting(false)
+                }
+              }}
+            >
+              {deleting ? "Deleting..." : "Delete"}
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
     </div>
   )
 }

src/pages/content-management/CourseFlowBuilderPage.tsx

@@ -1,6 +1,5 @@
 import { useEffect, useMemo, useState } from "react"
 import {
-  BadgeCheck,
   ChevronDown,
   ChevronRight,
   GripVertical,
@@ -32,9 +31,9 @@ import { Badge } from "../../components/ui/badge"
 import {
   getCourseCategories,
   getCoursesByCategory,
-  getLearningPath,
+  getSubModulesByCourse,
+  getVideosBySubModule,
   getQuestionSetsByOwner,
-  getSubModuleEntryAssessment,
   reorderCategories,
   reorderCourses,
   reorderSubModules,
@@ -194,9 +193,7 @@ export function CourseFlowBuilderPage() {
   const [practicesBySubCourse, setPracticesBySubCourse] = useState<Record<number, PracticeListItem[]>>(
     {},
   )
-  const [entryAssessmentBySubCourse, setEntryAssessmentBySubCourse] = useState<Record<number, QuestionSet | null>>(
+  const [videosBySubCourse, setVideosBySubCourse] = useState<Record<number, LearningPathVideo[]>>({})
-    {},
-  )
 
   const [loading, setLoading] = useState(true)
   const [loadingCourses, setLoadingCourses] = useState(false)
@@ -260,7 +257,9 @@ export function CourseFlowBuilderPage() {
       setLoadingCourses(true)
       try {
         const res = await getCoursesByCategory(selectedCategoryId)
-        const items = sortByDisplayOrder(res.data.data.courses ?? [])
+        const items = sortByDisplayOrder(
+          (res.data.data.courses ?? []).filter((course) => Number(course.category_id) === Number(selectedCategoryId)),
+        )
         setCoursesByCategory((prev) => ({ ...prev, [selectedCategoryId]: items }))
         setSelectedCourseId(items[0]?.id ?? null)
       } catch {
@@ -280,47 +279,94 @@ export function CourseFlowBuilderPage() {
     const load = async () => {
       setLoadingPath(true)
       try {
-        const res = await getLearningPath(selectedCourseId)
+        const selectedCourse = activeCourses.find((course) => course.id === selectedCourseId)
-        const path = res.data.data
+        const subRes = await getSubModulesByCourse(selectedCourseId)
+        const subCourses = sortByDisplayOrder((subRes.data.data.sub_courses ?? []) as any[]).map((sc) => ({
+          id: sc.id,
+          title: sc.title,
+          description: sc.description ?? "",
+          thumbnail: sc.thumbnail ?? "",
+          display_order: sc.display_order ?? 0,
+          level: sc.level ?? sc.cefr_level ?? "",
+          sub_level: sc.sub_level ?? "",
+          prerequisite_count: 0,
+          video_count: 0,
+          practice_count: 0,
+          prerequisites: [],
+          videos: [],
+          practices: [],
+        }))
+
         setLearningPath({
-          ...path,
+          course_id: selectedCourseId,
-          sub_courses: sortByDisplayOrder(path.sub_courses ?? []),
+          course_title: selectedCourse?.title ?? "",
+          description: selectedCourse?.description ?? "",
+          thumbnail: selectedCourse?.thumbnail ?? "",
+          intro_video_url: "",
+          category_id: selectedCategoryId ?? 0,
+          category_name: topLevelCategories.find((cat) => cat.id === selectedCategoryId)?.name ?? "",
+          sub_courses: subCourses,
         })
 
-        // Practices source of truth: question sets by SUB_COURSE owner.
+        if (subCourses.length === 0) {
-        const subCourses = path.sub_courses ?? []
+          setPracticesBySubCourse({})
-        if (subCourses.length > 0) {
+          setVideosBySubCourse({})
-          const ownerResults = await Promise.all(
+          return
+        }
+
+        const [ownerResults, videoResults] = await Promise.all([
+          Promise.all(
             subCourses.map(async (sc) => {
-              const setsRes = await getQuestionSetsByOwner("SUB_COURSE", sc.id)
+              const setsRes = await getQuestionSetsByOwner("SUB_MODULE", sc.id)
               return [sc.id, mapPracticeSetsToPracticeItems((setsRes.data.data ?? []) as QuestionSet[])] as const
             }),
-          )
+          ),
-          const practiceMap: Record<number, PracticeListItem[]> = {}
+          Promise.all(
-          ownerResults.forEach(([subCourseId, practiceItems]) => {
+            subCourses.map(async (sc) => {
-            practiceMap[subCourseId] = practiceItems
+              const videosRes = await getVideosBySubModule(sc.id)
-          })
+              const rows = videosRes.data?.data?.videos ?? []
-          setPracticesBySubCourse(practiceMap)
+              const mapped = sortByDisplayOrder(
-        } else {
+                rows.map((video: any, idx: number) => ({
-          setPracticesBySubCourse({})
+                  id: Number(video.id),
-        }
+                  title: String(video.title ?? "Video"),
+                  display_order: Number(video.display_order ?? idx),
+                  duration: Number(video.duration ?? 0),
+                  video_url: String(video.video_url ?? ""),
+                })),
+              )
+              return [sc.id, mapped] as const
+            }),
+          ),
+        ])
+
+        const practiceMap: Record<number, PracticeListItem[]> = {}
+        ownerResults.forEach(([subCourseId, practiceItems]) => {
+          practiceMap[subCourseId] = practiceItems
+        })
+        setPracticesBySubCourse(practiceMap)
+
+        const videoMap: Record<number, LearningPathVideo[]> = {}
+        videoResults.forEach(([subCourseId, videos]) => {
+          videoMap[subCourseId] = videos
+        })
+        setVideosBySubCourse(videoMap)
       } catch {
-        toast.error("Failed to load course sub-category learning path.")
+        toast.error("Failed to load course flow detail.")
         setLearningPath(null)
       } finally {
         setLoadingPath(false)
       }
     }
     load()
-  }, [selectedCourseId])
+  }, [selectedCourseId, activeCourses, selectedCategoryId, topLevelCategories])
 
   const loadSubCoursePracticeAndEntry = async (subCourseId: number) => {
-    if (practicesBySubCourse[subCourseId] && entryAssessmentBySubCourse[subCourseId] !== undefined) return
+    if (practicesBySubCourse[subCourseId] && videosBySubCourse[subCourseId]) return
     setLoadingPracticesBySubCourse((prev) => ({ ...prev, [subCourseId]: true }))
     try {
-      const [setsRes, entryRes] = await Promise.allSettled([
+      const [setsRes, videosRes] = await Promise.allSettled([
-        getQuestionSetsByOwner("SUB_COURSE", subCourseId),
+        getQuestionSetsByOwner("SUB_MODULE", subCourseId),
-        getSubModuleEntryAssessment(subCourseId),
+        getVideosBySubModule(subCourseId),
       ])
 
       // No practice sets is a valid empty-state scenario; do not toast for 404/empty.
@@ -339,20 +385,21 @@ export function CourseFlowBuilderPage() {
         [subCourseId]: mapPracticeSetsToPracticeItems(ownerSets),
       }))
 
-      // Entry assessment may legitimately be absent.
+      const videos =
-      let entryAssessment: QuestionSet | null = null
+        videosRes.status === "fulfilled"
-      if (entryRes.status === "fulfilled") {
+          ? sortByDisplayOrder(
-        entryAssessment = (entryRes.value.data.data ?? null) as QuestionSet | null
+              (videosRes.value.data?.data?.videos ?? []).map((video: any, idx: number) => ({
-      } else {
+                id: Number(video.id),
-        const status = entryRes.reason?.response?.status
+                title: String(video.title ?? "Video"),
-        if (status !== 404) {
+                display_order: Number(video.display_order ?? idx),
-          throw entryRes.reason
+                duration: Number(video.duration ?? 0),
-        }
+                video_url: String(video.video_url ?? ""),
-      }
+              })),
-
+            )
-      setEntryAssessmentBySubCourse((prev) => ({
+          : []
+      setVideosBySubCourse((prev) => ({
         ...prev,
-        [subCourseId]: entryAssessment,
+        [subCourseId]: videos,
       }))
     } catch {
       toast.error("Failed to load practice sets for course.")
@@ -694,6 +741,7 @@ export function CourseFlowBuilderPage() {
                     {learningPath.sub_courses.map((subCourse) => {
                       const expanded = expandedSubCourseIds.has(subCourse.id)
                       const practices = practicesBySubCourse[subCourse.id] ?? []
+                      const videos = videosBySubCourse[subCourse.id] ?? subCourse.videos ?? []
                       return (
                         <SortableRow key={subCourse.id} id={subCourse.id}>
                           <button
@@ -723,17 +771,12 @@ export function CourseFlowBuilderPage() {
                                     {subCourse.sub_level}
                                   </Badge>
                                 )}
-                                {entryAssessmentBySubCourse[subCourse.id] && (
+                                {/* entry-assessment route is no longer guaranteed across deployments */}
-                                  <span className="inline-flex items-center gap-1 text-emerald-600">
-                                    <BadgeCheck className="h-3.5 w-3.5" />
-                                    Entry assessment
-                                  </span>
-                                )}
                               </p>
                             </div>
                             <div className="flex w-full items-center justify-between gap-2 sm:w-auto sm:justify-end">
                               <Badge variant="secondary" className="text-[10px]">
-                                {subCourse.videos.length} videos / {practices.length || subCourse.practice_count} practices
+                                {videos.length} videos / {practices.length} practices
                               </Badge>
                               {expanded ? (
                                 <ChevronDown className="h-4 w-4 text-grayScale-400" />
@@ -755,16 +798,16 @@ export function CourseFlowBuilderPage() {
                                   onDragEnd={(event) => onVideosDragEnd(subCourse.id, event)}
                                 >
                                   <SortableContext
-                                    items={subCourse.videos.map((item) => item.id)}
+                                    items={videos.map((item) => item.id)}
                                     strategy={verticalListSortingStrategy}
                                   >
                                     <div className="space-y-1.5">
-                                      {subCourse.videos.length === 0 ? (
+                                      {videos.length === 0 ? (
                                         <p className="rounded-lg border border-dashed border-grayScale-200 px-2 py-2 text-[11px] text-grayScale-400">
                                           No videos
                                         </p>
                                       ) : (
-                                        subCourse.videos.map((video) => (
+                                        videos.map((video) => (
                                           <SortableChip
                                             key={video.id}
                                             id={video.id}
@@ -842,7 +885,7 @@ export function CourseFlowBuilderPage() {
           </p>
           <p>
             Practices load from <code>/question-sets/by-owner</code> filtered by
-            <code> set_type=PRACTICE</code>; entry assessment loads from dedicated course endpoint.
+            <code> set_type=PRACTICE</code> and <code>owner_type=SUB_MODULE</code>.
           </p>
         </CardContent>
       </Card>

src/pages/content-management/PracticeQuestionsPage.tsx

@@ -58,7 +58,13 @@ const typeColors: Record<QuestionType, string> = {
 }
 
 export function PracticeQuestionsPage() {
-  const { categoryId, courseId, subModuleId, practiceId } = useParams()
+  const { categoryId, courseId, subModuleId, levelId, practiceId } = useParams<{
+    categoryId: string
+    courseId: string
+    subModuleId?: string
+    levelId?: string
+    practiceId?: string
+  }>()
   const location = useLocation()
   
   const [questions, setQuestions] = useState<PracticeQuestion[]>([])
@@ -102,11 +108,14 @@ export function PracticeQuestionsPage() {
   const [saveError, setSaveError] = useState<string | null>(null)
 
   const backLink = useMemo(() => {
-    if (location.pathname.includes("/content/human-language/") && location.pathname.includes("/sub-module/")) {
+    if (location.pathname.includes("/content/human-language/") && location.pathname.includes("/level/") && levelId) {
+      return "/content/human-language"
+    }
+    if (location.pathname.includes("/content/human-language/") && location.pathname.includes("/sub-module/") && subModuleId) {
       return `/content/human-language/${categoryId}/${courseId}/sub-module/${subModuleId}`
     }
     return `/content/category/${categoryId}/courses/${courseId}/sub-modules/${subModuleId}`
-  }, [location.pathname, categoryId, courseId, subModuleId])
+  }, [location.pathname, categoryId, courseId, subModuleId, levelId])
 
   const buildDefaultOptions = (type: QuestionType, sampleAnswerText?: string): DraftOption[] => {
     if (type === "TRUE_FALSE") {

src/pages/content-management/SpeakingPage.tsx

@@ -1,5 +1,5 @@
 import { type ChangeEvent, useCallback, useEffect, useMemo, useRef, useState } from "react"
-import { ArrowLeft, ChevronDown, ChevronRight, Image as ImageIcon, Loader2, Mic, Plus, Trash2, Upload } from "lucide-react"
+import { ArrowLeft, ChevronDown, ChevronRight, Image as ImageIcon, Mic, Plus, Trash2, Upload } from "lucide-react"
 import { Card, CardContent, CardHeader, CardTitle } from "../../components/ui/card"
 import { Button } from "../../components/ui/button"
 import { Input } from "../../components/ui/input"
@@ -1926,7 +1926,7 @@ export function SpeakingPage() {
                           className="gap-1.5"
                         >
                           {uploadingIntroVideo ? (
-                            <Loader2 className="h-4 w-4 animate-spin" />
+                            <SpinnerIcon className="h-4 w-4" alt="" />
                           ) : (
                             <Upload className="h-4 w-4" />
                           )}

src/pages/content-management/SubCategoryCoursesPage.tsx

@@ -0,0 +1,144 @@
+import { useEffect, useState } from "react"
+import { Link, useNavigate, useParams } from "react-router-dom"
+import { ArrowLeft, BookOpen, ChevronRight } from "lucide-react"
+import spinnerSrc from "../../assets/Circular-indeterminate progress indicator.svg"
+import alertSrc from "../../assets/Alert.svg"
+import { Badge } from "../../components/ui/badge"
+import { getCoursesBySubCategoryId, getSubCategoriesByCategoryId } from "../../api/courses.api"
+import type { CategorySubCategoryListItem, SubCategoryCourseListItem } from "../../types/course.types"
+import { cn } from "../../lib/utils"
+
+export function SubCategoryCoursesPage() {
+  const { categoryId, subCategoryId } = useParams<{
+    categoryId: string
+    subCategoryId: string
+  }>()
+  const navigate = useNavigate()
+
+  const [subCategory, setSubCategory] = useState<CategorySubCategoryListItem | null>(null)
+  const [courses, setCourses] = useState<SubCategoryCourseListItem[]>([])
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState<string | null>(null)
+
+  useEffect(() => {
+    const run = async () => {
+      if (!categoryId || !subCategoryId) return
+      const cid = Number(categoryId)
+      const sid = Number(subCategoryId)
+      if (!Number.isFinite(cid) || !Number.isFinite(sid)) {
+        setError("Invalid route parameters")
+        setLoading(false)
+        return
+      }
+
+      setLoading(true)
+      setError(null)
+      try {
+        const [subRes, coursesRes] = await Promise.all([
+          getSubCategoriesByCategoryId(cid),
+          getCoursesBySubCategoryId(sid),
+        ])
+        const list = subRes.data?.data?.sub_categories ?? []
+        const found = Array.isArray(list) ? list.find((s) => s.id === sid) : undefined
+        setSubCategory(found ?? null)
+
+        const raw = coursesRes.data?.data?.courses
+        setCourses(Array.isArray(raw) ? raw : [])
+      } catch (e) {
+        console.error(e)
+        setError("Failed to load courses for this sub-category")
+        setCourses([])
+      } finally {
+        setLoading(false)
+      }
+    }
+    void run()
+  }, [categoryId, subCategoryId])
+
+  if (loading) {
+    return (
+      <div className="flex flex-col items-center justify-center py-32">
+        <img src={spinnerSrc} alt="" className="h-10 w-10 animate-spin" />
+        <p className="mt-4 text-sm text-grayScale-500">Loading courses…</p>
+      </div>
+    )
+  }
+
+  if (error) {
+    return (
+      <div className="flex items-center justify-center py-32">
+        <div className="mx-4 flex w-full max-w-md items-center gap-3 rounded-2xl border border-red-100 bg-red-50 px-6 py-5 shadow-sm">
+          <img src={alertSrc} alt="" className="h-10 w-10 shrink-0" />
+          <p className="text-sm font-medium text-red-600">{error}</p>
+        </div>
+      </div>
+    )
+  }
+
+  const label = subCategory?.name ?? "Sub-category"
+
+  return (
+    <div className="space-y-6">
+      <div className="rounded-2xl border border-grayScale-100 bg-white px-5 py-4 shadow-sm sm:px-6 sm:py-5">
+        <div className="flex flex-col gap-4 sm:flex-row sm:items-start sm:justify-between">
+          <div className="flex items-start gap-3.5">
+            <Link
+              to={`/content/category/${categoryId}/courses`}
+              className="mt-0.5 grid h-9 w-9 shrink-0 place-items-center rounded-xl bg-grayScale-50 text-grayScale-500 transition-colors hover:bg-brand-50 hover:text-brand-600"
+            >
+              <ArrowLeft className="h-4 w-4" />
+            </Link>
+            <div>
+              <p className="text-xs font-medium text-grayScale-400">Sub-category</p>
+              <h1 className="text-xl font-bold text-grayScale-700 sm:text-2xl">{label}</h1>
+              <p className="mt-0.5 text-sm text-grayScale-400">
+                {courses.length} course{courses.length !== 1 ? "s" : ""} — open a course to manage sub-modules
+              </p>
+            </div>
+          </div>
+        </div>
+      </div>
+
+      {courses.length === 0 ? (
+        <div className="rounded-xl border border-dashed border-grayScale-200 bg-grayScale-50/50 px-6 py-14 text-center">
+          <p className="text-sm font-medium text-grayScale-600">No courses in this sub-category yet</p>
+          <p className="mt-1 text-sm text-grayScale-400">Add a course from your authoring flow or API.</p>
+        </div>
+      ) : (
+        <div className="space-y-3">
+          {courses.map((c) => (
+            <button
+              key={c.id}
+              type="button"
+              onClick={() =>
+                navigate(`/content/category/${categoryId}/courses/${c.id}/sub-modules`)
+              }
+              className={cn(
+                "flex w-full items-center justify-between gap-4 rounded-xl border border-grayScale-200 bg-white px-4 py-4 text-left shadow-sm transition-all",
+                "hover:border-brand-200 hover:bg-brand-50/40 hover:shadow-md",
+              )}
+            >
+              <div className="flex min-w-0 items-center gap-3">
+                <div className="grid h-10 w-10 shrink-0 place-items-center rounded-lg bg-grayScale-50 text-grayScale-400">
+                  <BookOpen className="h-5 w-5" />
+                </div>
+                <div className="min-w-0">
+                  <p className="font-semibold text-grayScale-800">{c.title}</p>
+                  {c.description?.trim() ? (
+                    <p className="mt-0.5 line-clamp-2 text-sm text-grayScale-500">{c.description}</p>
+                  ) : null}
+                </div>
+              </div>
+              <div className="flex shrink-0 items-center gap-3">
+                <Badge variant={c.is_active ? "success" : "secondary"} className="text-[11px]">
+                  {c.is_active ? "Active" : "Inactive"}
+                </Badge>
+                <ChevronRight className="h-5 w-5 text-grayScale-300" />
+              </div>
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  )
+}

src/pages/content-management/SubCourseContentPage.tsx

@@ -103,9 +103,10 @@ export function SubModuleContentPage() {
 
       try {
         const subCoursesRes = await getSubModulesByCourse(Number(courseId))
-        const foundSubCourse = subCoursesRes.data.data.sub_courses?.find(
+        const list = subCoursesRes.data?.data?.sub_courses
-          (sc) => sc.id === Number(subModuleId)
+        const foundSubCourse = Array.isArray(list)
-        )
+          ? list.find((sc) => sc.id === Number(subModuleId))
+          : undefined
         setSubCourse(foundSubCourse ?? null)
       } catch (err) {
         console.error("Failed to fetch course data:", err)
@@ -123,7 +124,9 @@ export function SubModuleContentPage() {
     setPracticesLoading(true)
     try {
       const res = await getQuestionSetsByOwner("SUB_MODULE", Number(subModuleId))
-      setPractices(res.data.data ?? [])
+      const raw = res.data?.data
+      const list = Array.isArray(raw) ? raw : (raw as { question_sets?: QuestionSet[] })?.question_sets ?? []
+      setPractices(Array.isArray(list) ? list : [])
     } catch (err) {
       console.error("Failed to fetch practices:", err)
     } finally {
@@ -136,7 +139,8 @@ export function SubModuleContentPage() {
     setVideosLoading(true)
     try {
       const res = await getVideosBySubModule(Number(subModuleId))
-      setVideos(res.data.data.videos ?? [])
+      const vids = res.data?.data?.videos ?? []
+      setVideos(Array.isArray(vids) ? vids : [])
     } catch (err) {
       console.error("Failed to fetch videos:", err)
     } finally {
@@ -154,7 +158,7 @@ export function SubModuleContentPage() {
         limit: ratingsPageSize,
         offset,
       })
-      setRatings(res.data.data ?? [])
+      setRatings(res.data?.data ?? [])
     } catch (err) {
       console.error("Failed to fetch ratings:", err)
     } finally {
@@ -405,8 +409,8 @@ export function SubModuleContentPage() {
       const idMatch = video.video_url?.match(/(\d{5,})/)
       const vimeoId = idMatch?.[1] ?? "76979871" // fallback to Big Buck Bunny
       const res = await getVimeoSample(vimeoId)
-      setPreviewIframe(res.data.data.iframe)
+      setPreviewIframe(res.data?.data?.iframe ?? "")
-      setPreviewVideo(res.data.data.video)
+      setPreviewVideo(res.data?.data?.video ?? null)
     } catch {
       setPreviewIframe("")
     } finally {
@@ -414,7 +418,7 @@ export function SubModuleContentPage() {
     }
   }
 
-  const filteredPractices = practices.filter((practice) => {
+  const filteredPractices = (Array.isArray(practices) ? practices : []).filter((practice) => {
     if (statusFilter === "all") return true
     if (statusFilter === "published") return practice.status === "PUBLISHED"
     if (statusFilter === "draft") return practice.status === "DRAFT"
@@ -440,6 +444,19 @@ export function SubModuleContentPage() {
     )
   }
 
+  if (!subCourse) {
+    return (
+      <div className="flex flex-col items-center justify-center py-20">
+        <img src={alertSrc} alt="" className="h-12 w-12" />
+        <p className="mt-3 text-sm font-medium text-grayScale-600">Sub-module not found</p>
+        <p className="mt-1 text-sm text-grayScale-400">It may have been removed or the link is invalid.</p>
+        <Button className="mt-6" variant="outline" asChild>
+          <Link to={`/content/category/${categoryId}/courses/${courseId}/sub-modules`}>Back to sub-modules</Link>
+        </Button>
+      </div>
+    )
+  }
+
   return (
     <div className="space-y-6">
       {/* Back Button */}
@@ -590,7 +607,7 @@ export function SubModuleContentPage() {
                       <div className="flex items-center gap-3 text-xs text-grayScale-400">
                         <div className="flex items-center gap-1.5">
                           <Layers className="h-3.5 w-3.5" />
-                          <span>{practice.owner_type.replace("_", " ")}</span>
+                          <span>{String(practice.owner_type ?? "SUB_MODULE").replace(/_/g, " ")}</span>
                         </div>
                         {practice.shuffle_questions && (
                           <span className="rounded-full bg-amber-50 px-2 py-0.5 text-[11px] font-medium text-amber-600 ring-1 ring-inset ring-amber-200">Shuffle ON</span>
@@ -599,11 +616,13 @@ export function SubModuleContentPage() {
 
                       <div className="mt-auto flex items-center justify-between border-t border-grayScale-100 pt-3">
                         <span className="text-xs font-medium text-grayScale-400">
-                          {new Date(practice.created_at).toLocaleDateString("en-US", {
+                          {practice.created_at
-                            month: "short",
+                            ? new Date(practice.created_at).toLocaleDateString("en-US", {
-                            day: "numeric",
+                                month: "short",
-                            year: "numeric",
+                                day: "numeric",
-                          })}
+                                year: "numeric",
+                              })
+                            : "—"}
                         </span>
                         <div className="flex gap-0.5" onClick={(e) => e.stopPropagation()}>
                           <button

src/pages/issues/IssuesPage.tsx

@@ -95,12 +95,13 @@ function getStatusConfig(status: string): {
   }
 }
 
-function getIssueTypeConfig(type: string): {
+function getIssueTypeConfig(type: string | null | undefined): {
   label: string;
   classes: string;
   icon: typeof Bug;
 } {
-  switch (type) {
+  const t = String(type ?? "").trim();
+  switch (t) {
     case "bug":
       return {
         label: "Bug",
@@ -133,7 +134,7 @@ function getIssueTypeConfig(type: string): {
       };
     default:
       return {
-        label: type.charAt(0).toUpperCase() + type.slice(1),
+        label: t ? t.charAt(0).toUpperCase() + t.slice(1) : "Other",
         classes: "bg-grayScale-100 text-grayScale-600 border-grayScale-200",
         icon: HelpCircle,
       };
@@ -173,8 +174,10 @@ function getRelativeTime(dateStr: string): string {
   return formatDate(dateStr);
 }
 
-function formatRoleLabel(role: string): string {
+function formatRoleLabel(role: string | null | undefined): string {
-  return role
+  const r = String(role ?? "").trim();
+  if (!r) return "—";
+  return r
     .split("_")
     .map((w) => w.charAt(0).toUpperCase() + w.slice(1).toLowerCase())
     .join(" ");
@@ -221,8 +224,9 @@ export function IssuesPage() {
         offset: (page - 1) * pageSize,
       };
       const res = await getIssues(filters);
-      setIssues(res.data.data.issues);
+      const payload = res.data?.data;
-      setTotalCount(res.data.data.total_count);
+      setIssues(Array.isArray(payload?.issues) ? payload.issues : []);
+      setTotalCount(typeof payload?.total_count === "number" ? payload.total_count : 0);
     } catch (error) {
       console.error("Failed to fetch issues:", error);
       setIssues([]);
@@ -241,7 +245,7 @@ export function IssuesPage() {
     setDetailLoading(true);
     try {
       const res = await getIssueById(issueId);
-      setSelectedIssue(res.data.data);
+      setSelectedIssue(res.data?.data ?? null);
     } catch (error) {
       console.error("Failed to fetch issue detail:", error);
     } finally {
@@ -305,16 +309,15 @@ export function IssuesPage() {
   };
 
   // Client-side filtering (status, type, search)
-  const filteredIssues = issues.filter((issue) => {
+  const filteredIssues = (Array.isArray(issues) ? issues : []).filter((issue) => {
     if (statusFilter && issue.status !== statusFilter) return false;
     if (typeFilter && issue.issue_type !== typeFilter) return false;
     if (searchQuery) {
       const q = searchQuery.toLowerCase();
-      return (
+      const subject = String(issue.subject ?? "").toLowerCase();
-        issue.subject.toLowerCase().includes(q) ||
+      const description = String(issue.description ?? "").toLowerCase();
-        issue.description.toLowerCase().includes(q) ||
+      const issueType = String(issue.issue_type ?? "").toLowerCase();
-        issue.issue_type.toLowerCase().includes(q)
+      return subject.includes(q) || description.includes(q) || issueType.includes(q);
-      );
     }
     return true;
   });
@@ -537,10 +540,10 @@ export function IssuesPage() {
                         </div>
                         <div className="min-w-0">
                           <p className="text-sm font-medium text-grayScale-600 truncate">
-                            {issue.subject}
+                            {issue.subject?.trim() ? issue.subject : "—"}
                           </p>
                           <p className="text-xs text-grayScale-400 truncate mt-0.5">
-                            {issue.description}
+                            {issue.description?.trim() ? issue.description : "No description"}
                           </p>
                         </div>
                       </div>
@@ -572,6 +575,9 @@ export function IssuesPage() {
                               {getStatusConfig(s).label}
                             </option>
                           ))}
+                          {!STATUSES.includes(issue.status as (typeof STATUSES)[number]) && issue.status ? (
+                            <option value={issue.status}>{getStatusConfig(issue.status).label}</option>
+                          ) : null}
                         </select>
                         <ChevronDown className="absolute right-2 top-1/2 h-3 w-3 -translate-y-1/2 pointer-events-none opacity-50" />
                       </div>

src/pages/notifications/CreateNotificationPage.tsx

@@ -1,11 +1,12 @@
 import { useEffect, useMemo, useState } from "react"
 import { useNavigate } from "react-router-dom"
-import { Bell, Loader2, Mail, MailOpen, Megaphone } from "lucide-react"
+import { Bell, Mail, MailOpen, Megaphone } from "lucide-react"
 import { Card, CardContent } from "../../components/ui/card"
 import { Button } from "../../components/ui/button"
 import { Input } from "../../components/ui/input"
 import { Textarea } from "../../components/ui/textarea"
 import { FileUpload } from "../../components/ui/file-upload"
+import { SpinnerIcon } from "../../components/ui/spinner-icon"
 import { cn } from "../../lib/utils"
 import { getTeamMembers } from "../../api/team.api"
 import type { TeamMember } from "../../types/team.types"
@@ -282,7 +283,7 @@ export function CreateNotificationPage() {
               >
                 {sending ? (
                   <>
-                    <Loader2 className="mr-2 h-3.5 w-3.5 animate-spin" />
+                    <SpinnerIcon className="mr-2 h-3.5 w-3.5" alt="" />
                     Sending…
                   </>
                 ) : (
@@ -347,7 +348,7 @@ export function CreateNotificationPage() {
                 <div className="max-h-64 space-y-1.5 overflow-y-auto rounded-lg border border-grayScale-100 bg-grayScale-50/60 p-2">
                   {recipientsLoading && (
                     <div className="flex items-center justify-center py-6 text-xs text-grayScale-400">
-                      <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                      <SpinnerIcon className="mr-2 h-4 w-4" alt="" />
                       Loading users…
                     </div>
                   )}

src/pages/role-management/RolesListPage.tsx

@@ -1,8 +1,18 @@
-import { useEffect, useMemo, useState } from "react"
+import { useCallback, useEffect, useMemo, useState } from "react"
 import { useNavigate } from "react-router-dom"
 import {
-  Plus, Search, Shield, ShieldCheck, ChevronLeft, ChevronRight,
+  Plus,
-  AlertCircle, Eye, X, Pencil, Check,
+  Search,
+  Shield,
+  ShieldCheck,
+  ChevronLeft,
+  ChevronRight,
+  AlertCircle,
+  Eye,
+  X,
+  Pencil,
+  Check,
+  Trash2,
 } from "lucide-react"
 import { Button } from "../../components/ui/button"
 import { Card, CardContent } from "../../components/ui/card"
@@ -12,7 +22,14 @@ import { Textarea } from "../../components/ui/textarea"
 import {
   Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription,
 } from "../../components/ui/dialog"
-import { getRoles, getRoleDetail, getAllPermissions, setRolePermissions, updateRole } from "../../api/rbac.api"
+import {
+  getRoles,
+  getRoleDetail,
+  getAllPermissions,
+  setRolePermissions,
+  updateRole,
+  deleteRole,
+} from "../../api/rbac.api"
 import type { Role, RoleDetail, RolePermission } from "../../types/rbac.types"
 import { cn } from "../../lib/utils"
 import { toast } from "sonner"
@@ -36,6 +53,11 @@ export function RolesListPage() {
   const [detailOpen, setDetailOpen] = useState(false)
   const [detailLoading, setDetailLoading] = useState(false)
 
+  // Delete modal state
+  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false)
+  const [roleToDelete, setRoleToDelete] = useState<Role | null>(null)
+  const [deleteLoading, setDeleteLoading] = useState(false)
+
   // Role info editing state
   const [editingRole, setEditingRole] = useState(false)
   const [editName, setEditName] = useState("")
@@ -59,27 +81,28 @@ export function RolesListPage() {
     return () => clearTimeout(timer)
   }, [query])
 
+  const fetchRoles = useCallback(async () => {
+    setLoading(true)
+    setError(null)
+    try {
+      const res = await getRoles({
+        query: debouncedQuery || undefined,
+        page,
+        page_size: pageSize,
+      })
+      setRoles(res.data.data.roles ?? [])
+      setTotal(res.data.data.total ?? 0)
+    } catch {
+      setError("Failed to load roles.")
+    } finally {
+      setLoading(false)
+    }
+  }, [debouncedQuery, page, pageSize])
+
   // Fetch roles
   useEffect(() => {
-    const fetchRoles = async () => {
-      setLoading(true)
-      setError(null)
-      try {
-        const res = await getRoles({
-          query: debouncedQuery || undefined,
-          page,
-          page_size: pageSize,
-        })
-        setRoles(res.data.data.roles ?? [])
-        setTotal(res.data.data.total ?? 0)
-      } catch {
-        setError("Failed to load roles.")
-      } finally {
-        setLoading(false)
-      }
-    }
     fetchRoles()
-  }, [debouncedQuery, page, pageSize])
+  }, [fetchRoles])
 
   // Open role detail
   const handleViewRole = async (roleId: number) => {
@@ -97,6 +120,45 @@ export function RolesListPage() {
     }
   }
 
+  const handleDeleteRoleClick = (role: Role) => {
+    setRoleToDelete(role)
+    setDeleteDialogOpen(true)
+  }
+
+  const handleCancelDeleteRole = () => {
+    setDeleteDialogOpen(false)
+    setRoleToDelete(null)
+  }
+
+  const handleConfirmDeleteRole = async () => {
+    if (!roleToDelete) return
+    setDeleteLoading(true)
+    try {
+      const res = await deleteRole(roleToDelete.id)
+      toast.success(res.data.message ?? "Role deleted successfully")
+
+      // Close dialogs if the deleted role is currently opened.
+      if (selectedRole?.id === roleToDelete.id) {
+        setDetailOpen(false)
+        setSelectedRole(null)
+        setEditingPermissions(false)
+        setEditingRole(false)
+        setPermSearch("")
+      }
+
+      setRoleToDelete(null)
+      setDeleteDialogOpen(false)
+      await fetchRoles()
+    } catch (err: unknown) {
+      const message =
+        (err as { response?: { data?: { message?: string } } })?.response?.data?.message ??
+        "Failed to delete role."
+      toast.error(message)
+    } finally {
+      setDeleteLoading(false)
+    }
+  }
+
   // Enter role info edit mode
   const handleEditRole = () => {
     if (!selectedRole) return
@@ -302,7 +364,7 @@ export function RolesListPage() {
               {roles.map((role) => (
                 <Card
                   key={role.id}
-                  className="overflow-hidden shadow-sm transition-shadow hover:shadow-md"
+                  className="overflow-hidden border border-grayScale-100 shadow-sm transition-all hover:-translate-y-0.5 hover:shadow-md"
                 >
                   <div
                     className={cn(
@@ -312,7 +374,7 @@ export function RolesListPage() {
                         : "bg-gradient-to-r from-brand-500 to-brand-600",
                     )}
                   />
-                  <CardContent className="p-5">
+                  <CardContent className="space-y-4 p-5">
                     <div className="flex items-start justify-between gap-3">
                       <div className="flex items-center gap-2.5">
                         <div
@@ -330,32 +392,63 @@ export function RolesListPage() {
                           )}
                         </div>
                         <div>
-                          <h3 className="text-sm font-semibold text-grayScale-700">{role.name}</h3>
+                          <h3 className="text-sm font-semibold uppercase tracking-wide text-grayScale-700">
-                          <p className="mt-0.5 text-xs text-grayScale-400 line-clamp-1">
+                            {role.name}
-                            {role.description}
+                          </h3>
+                          <p className="mt-0.5 text-xs text-grayScale-500 line-clamp-2">
+                            {role.description?.trim() || "No description provided for this role."}
                           </p>
                         </div>
                       </div>
-                      {role.is_system && (
+                      <Badge
-                        <Badge variant="warning" className="shrink-0 text-[10px]">
+                        variant={role.is_system ? "warning" : "outline"}
-                          System
+                        className="shrink-0 text-[10px]"
-                        </Badge>
+                      >
-                      )}
+                        {role.is_system ? "System" : "Custom"}
+                      </Badge>
                     </div>
 
-                    <div className="mt-4 flex items-center justify-between">
+                    <div className="grid grid-cols-2 gap-2 rounded-xl border border-grayScale-100 bg-grayScale-50/70 p-2.5 text-[11px]">
+                      <div>
+                        <p className="text-grayScale-400">Role ID</p>
+                        <p className="font-semibold text-grayScale-700">#{role.id}</p>
+                      </div>
+                      <div>
+                        <p className="text-grayScale-400">Created</p>
+                        <p className="font-semibold text-grayScale-700">
+                          {new Date(role.created_at).toLocaleDateString()}
+                        </p>
+                      </div>
+                    </div>
+
+                    <div className="flex items-center justify-between">
                       <span className="text-[11px] text-grayScale-400">
-                        Created {new Date(role.created_at).toLocaleDateString()}
+                        Open details to view permissions
                       </span>
-                      <Button
+                      <div className="flex items-center gap-2">
-                        variant="outline"
+                        {!role.is_system && (
-                        size="sm"
+                          <Button
-                        className="h-8 gap-1.5 text-xs"
+                            type="button"
-                        onClick={() => handleViewRole(role.id)}
+                            variant="destructive"
-                      >
+                            size="icon"
-                        <Eye className="h-3.5 w-3.5" />
+                            className="h-8 w-8"
-                        View
+                            onClick={() => handleDeleteRoleClick(role)}
-                      </Button>
+                            disabled={deleteLoading}
+                            aria-label={`Delete role ${role.name}`}
+                          >
+                            <Trash2 className="h-4 w-4" />
+                          </Button>
+                        )}
+                        <Button
+                          variant="outline"
+                          size="sm"
+                          className="h-8 gap-1.5 text-xs"
+                          onClick={() => handleViewRole(role.id)}
+                        >
+                          <Eye className="h-3.5 w-3.5" />
+                          View
+                        </Button>
+                      </div>
                     </div>
                   </CardContent>
                 </Card>
@@ -689,6 +782,55 @@ export function RolesListPage() {
           )}
         </DialogContent>
       </Dialog>
+
+      {/* Delete role dialog */}
+      <Dialog
+        open={deleteDialogOpen}
+        onOpenChange={(open) => {
+          setDeleteDialogOpen(open)
+          if (!open) handleCancelDeleteRole()
+        }}
+      >
+        <DialogContent className="max-w-sm">
+          <DialogHeader>
+            <DialogTitle className="flex items-center gap-2 text-red-600">
+              <Trash2 className="h-5 w-5" />
+              Delete Role
+            </DialogTitle>
+            <DialogDescription>
+              Are you sure you want to delete this role? This action cannot be undone.
+            </DialogDescription>
+          </DialogHeader>
+
+          {roleToDelete && (
+            <div className="rounded-lg bg-red-50 border border-red-100 p-3">
+              <p className="text-sm font-medium text-red-700">{roleToDelete.name}</p>
+              <p className="text-xs text-red-500 mt-0.5">Role #{roleToDelete.id}</p>
+            </div>
+          )}
+
+          <div className="flex justify-end gap-2 pt-2">
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={handleCancelDeleteRole}
+              disabled={deleteLoading}
+            >
+              Cancel
+            </Button>
+            <Button
+              variant="destructive"
+              size="sm"
+              className="gap-1.5"
+              disabled={deleteLoading || !roleToDelete}
+              onClick={handleConfirmDeleteRole}
+            >
+              {deleteLoading ? <SpinnerIcon className="h-3.5 w-3.5" /> : <Trash2 className="h-3.5 w-3.5" />}
+              {deleteLoading ? "Deleting..." : "Delete"}
+            </Button>
+          </div>
+        </DialogContent>
+      </Dialog>
     </div>
   )
 }

src/types/course.types.ts

@@ -45,6 +45,7 @@ export interface GetCoursesResponse {
 
 export interface CreateCourseRequest {
   category_id: number
+  sub_category_id?: number | null
   title: string
   description: string
 }
@@ -172,7 +173,13 @@ export interface GetModulesResponse {
 export interface CreateModuleRequest {
   level_id: number
   title: string
-  content: string
+  /** Legacy field kept for backward compatibility. */
+  content?: string
+  /** Preferred field for module detail text. */
+  description?: string
+  icon_url?: string
+  display_order?: number
+  is_active?: boolean
 }
 
 /** @deprecated Use UpdateSubCourseRequest instead */
@@ -192,6 +199,8 @@ export interface UpdateModuleStatusRequest {
 export interface SubCourse {
   id: number
   course_id: number
+  /** Present when derived from course hierarchy rows (levels → modules → sub-modules). */
+  level_id?: number
   module_id?: number
   title: string
   description: string
@@ -701,6 +710,72 @@ export interface HumanLanguageLesson {
   practices: LearningPathPractice[]
 }
 
+export interface SubModuleLessonDetail {
+  id: number
+  sub_module_id: number
+  display_order: number
+  is_active: boolean
+  created_at: string
+  title: string
+  description?: string | null
+  thumbnail?: string | null
+  teaching_text?: string | null
+  teaching_image_url?: string | null
+  teaching_audio_url?: string | null
+  teaching_video_url?: string | null
+}
+
+export interface SubModuleLesson {
+  id: number
+  sub_module_id: number
+  display_order: number
+  is_active: boolean
+  created_at: string
+  title: string
+  description?: string | null
+  thumbnail?: string | null
+  teaching_text?: string | null
+  teaching_image_url?: string | null
+  teaching_audio_url?: string | null
+  teaching_video_url?: string | null
+}
+
+export interface GetSubModuleLessonDetailResponse {
+  message: string
+  data: SubModuleLessonDetail
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+export interface UpdateSubModuleLessonRequest {
+  title: string
+  description?: string | null
+  thumbnail?: string | null
+  teaching_text?: string | null
+  teaching_image_url?: string | null
+  teaching_audio_url?: string | null
+  teaching_video_url?: string | null
+  display_order: number
+  is_active: boolean
+}
+
+export interface UpdateSubModuleLessonResponse {
+  message: string
+  data: SubModuleLessonDetail
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+export interface GetSubModuleLessonsResponse {
+  message: string
+  data: SubModuleLesson[]
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
 export interface GetHumanLanguageLessonsResponse {
   message: string
   data: {
@@ -714,10 +789,209 @@ export interface GetHumanLanguageLessonsResponse {
   metadata: unknown
 }
 
+/** Row from GET /course-management/human-language/sub-categories */
+export interface HumanLanguageSubCategoryListItem {
+  id: number
+  category_id: number
+  category_name: string
+  name: string
+  description?: string | null
+  display_order: number
+  is_active: boolean
+  created_at: string
+  /** Present on some payloads; ignore if unused. */
+  total_count?: number
+}
+
+export interface GetHumanLanguageSubCategoriesResponse {
+  message: string
+  data: {
+    sub_categories: HumanLanguageSubCategoryListItem[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/categories/:categoryId/sub-categories */
+export interface CategorySubCategoryListItem {
+  id: number
+  category_id: number
+  category_name: string
+  name: string
+  description?: string | null
+  display_order: number
+  is_active: boolean
+  created_at: string
+  /** Sometimes echoed per row by the API; safe to ignore. */
+  total_count?: number
+}
+
+export interface GetCategorySubCategoriesResponse {
+  message: string
+  data: {
+    sub_categories: CategorySubCategoryListItem[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/sub-categories/:subCategoryId/courses */
+export interface SubCategoryCourseListItem {
+  id: number
+  category_id: number
+  sub_category_id: number
+  title: string
+  description?: string | null
+  thumbnail?: string | null
+  intro_video_url?: string | null
+  is_active: boolean
+  total_count?: number
+}
+
+export interface GetSubCategoryCoursesResponse {
+  message: string
+  data: {
+    courses: SubCategoryCourseListItem[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/courses/:courseId/levels or GET /course-management/levels */
+export interface CourseLevelRow {
+  id: number
+  course_id: number
+  cefr_level: string
+  display_order: number
+  is_active: boolean
+  created_at: string
+  title: string
+  description?: string | null
+  thumbnail?: string | null
+  total_count?: number
+}
+
+export interface GetCourseLevelsForCourseResponse {
+  message: string
+  data: {
+    levels: CourseLevelRow[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+export interface GetCourseLevelsAllResponse {
+  message: string
+  data: {
+    levels: CourseLevelRow[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+export interface GetCourseLevelByIdResponse {
+  message: string
+  data: CourseLevelRow
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/modules/:moduleId/sub-modules */
+export interface CourseSubModuleListItem {
+  id: number
+  module_id: number
+  title: string
+  description?: string | null
+  display_order: number
+  is_active: boolean
+  created_at: string
+  legacy_sub_course_id?: number | null
+  thumbnail?: string | null
+  tips?: string | null
+  total_count?: number
+}
+
+export interface GetSubModulesByModuleResponse {
+  message: string
+  data: {
+    sub_modules: CourseSubModuleListItem[]
+    total_count: number
+  }
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/human-language/hierarchy */
+export interface HumanLanguageHierarchyFlatRow {
+  category_id: number
+  category_name: string
+  sub_category_id?: number | null
+  sub_category_name?: string | null
+  course_id?: number | null
+  course_title?: string | null
+}
+
+export interface GetHumanLanguageHierarchyFlatResponse {
+  message: string
+  data: HumanLanguageHierarchyFlatRow[]
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
+/** Row from GET /course-management/courses/:courseId/hierarchy */
+export interface CourseHierarchyRow {
+  course_id: number
+  course_title: string
+  level_id?: number | null
+  cefr_level?: string | null
+  level_title?: string | null
+  level_description?: string | null
+  level_thumbnail?: string | null
+  module_id?: number | null
+  module_title?: string | null
+  module_icon_url?: string | null
+  sub_module_id?: number | null
+  sub_module_title?: string | null
+  sub_module_description?: string | null
+  sub_module_thumbnail?: string | null
+  sub_module_tips?: string | null
+  sub_module_display_order?: number | null
+}
+
+export interface GetCourseHierarchyResponse {
+  message: string
+  data: CourseHierarchyRow[]
+  success: boolean
+  status_code: number
+  metadata: unknown
+}
+
 export interface HumanLanguageSubModule {
   id: number
   title: string
   videos: LearningPathVideo[]
+  lessons?: {
+    id: number
+    question_set_id: number
+    title: string
+    status: string
+    question_count: number
+    display_order: number
+    intro_video_url?: string | null
+  }[]
   practices: LearningPathPractice[]
 }
 
@@ -728,6 +1002,7 @@ export interface HumanLanguageModule {
 }
 
 export interface HumanLanguageLevelTree {
+  level_id?: number
   level: string
   modules: HumanLanguageModule[]
 }

src/types/rbac.types.ts

@@ -60,6 +60,14 @@ export interface CreateRoleResponse {
   metadata: unknown
 }
 
+export interface DeleteRoleResponse {
+  message: string
+  success: boolean
+  status_code: number
+  // Some backends may include extra fields; keep it optional for compatibility.
+  metadata?: unknown
+}
+
 export interface SetRolePermissionsRequest {
   permission_ids: number[]
 }