Merge branch 'remove-cover-page'

server/db.test.ts

@@ -1,3 +1,6 @@
+import { existsSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
 import { afterEach, describe, expect, it, setSystemTime } from 'bun:test'
 import { createEmptyBook, createEmptyTeachingDesign } from '../src/domain/teachingDesign'
 import {
@@ -10,6 +13,12 @@ afterEach(() => {
   setSystemTime()
 })
 
+function tempDbPath(name: string): string {
+  const path = join(tmpdir(), `fake-teaching-design-${name}-${crypto.randomUUID()}.db`)
+  if (existsSync(path)) rmSync(path)
+  return path
+}
+
 describe('db', () => {
   it('creates a book with empty data', () => {
     const db = openDb(':memory:')
@@ -55,13 +64,85 @@ describe('db', () => {
     const db = openDb(':memory:')
     const created = createBook(db, '示例整本')
     const data = createEmptyBook()
-    data.cover.courseName = 'Web 前端开发'
+    data.designs.push(createEmptyTeachingDesign('1.md'))
 
     setSystemTime(new Date('2026-02-01T00:00:00.000Z'))
     const result = saveBookData(db, created.id, data)
 
     expect(result).toEqual({ id: created.id, name: '示例整本', updatedAt: '2026-02-01T00:00:00.000Z' })
-    expect(getBook(db, created.id)?.data.cover.courseName).toBe('Web 前端开发')
+    expect(getBook(db, created.id)?.data).not.toHaveProperty('cover')
+  })
+
+  it('migrates legacy cover data and cover selection on open', () => {
+    const path = tempDbPath('cover-migration')
+    const db = openDb(path)
+    const design = createEmptyTeachingDesign('1.md')
+    const legacy = {
+      schemaVersion: 1,
+      cover: { courseName: '旧课程', teacherName: '旧教师' },
+      designs: [design],
+      selectedId: 'cover',
+      updatedAt: '2026-01-01T00:00:00.000Z',
+    }
+    db.run('INSERT INTO books (id, name, data, created_at, updated_at) VALUES (?, ?, ?, ?, ?)', [
+      'legacy-1',
+      '旧整本',
+      JSON.stringify(legacy),
+      '2026-01-01T00:00:00.000Z',
+      '2026-01-01T00:00:00.000Z',
+    ])
+    db.close()
+
+    const reopened = openDb(path)
+    const migrated = getBook(reopened, 'legacy-1')!.data
+    const raw = reopened.query<{ data: string }, [string]>('SELECT data FROM books WHERE id = ?').get('legacy-1')!.data
+    reopened.close()
+    rmSync(path)
+
+    expect(migrated).not.toHaveProperty('cover')
+    expect(migrated.selectedId).toBe(design.id)
+    expect(JSON.parse(raw)).not.toHaveProperty('cover')
+  })
+
+  it('migrates legacy cover selection to null when no lessons exist', () => {
+    const path = tempDbPath('empty-cover-migration')
+    const db = openDb(path)
+    db.run('INSERT INTO books (id, name, data, created_at, updated_at) VALUES (?, ?, ?, ?, ?)', [
+      'legacy-empty',
+      '空整本',
+      JSON.stringify({
+        schemaVersion: 1,
+        cover: { courseName: '旧课程', teacherName: '旧教师' },
+        designs: [],
+        selectedId: 'cover',
+        updatedAt: '2026-01-01T00:00:00.000Z',
+      }),
+      '2026-01-01T00:00:00.000Z',
+      '2026-01-01T00:00:00.000Z',
+    ])
+    db.close()
+
+    const reopened = openDb(path)
+    const migrated = getBook(reopened, 'legacy-empty')!.data
+    reopened.close()
+    rmSync(path)
+
+    expect(migrated).not.toHaveProperty('cover')
+    expect(migrated.selectedId).toBeNull()
+  })
+
+  it('normalizes invalid selected ids to the first lesson', () => {
+    const db = openDb(':memory:')
+    const created = createBook(db, '示例整本')
+    const data = createEmptyBook()
+    const design = createEmptyTeachingDesign('1.md')
+    data.designs.push(design)
+    db.run('UPDATE books SET data = ? WHERE id = ?', [
+      JSON.stringify({ ...data, selectedId: 'missing-id' }),
+      created.id,
+    ])
+
+    expect(getBook(db, created.id)?.data.selectedId).toBe(design.id)
   })
 
   it('returns null when saving data for a missing book', () => {

server/db.ts

@@ -28,6 +28,16 @@ interface BookRow {
   updated_at: string
 }
 
+type StoredTeachingBook = Omit<TeachingBook, 'selectedId'> & {
+  cover?: unknown
+  selectedId?: string | null
+}
+
+interface NormalizedBookData {
+  data: TeachingBook
+  changed: boolean
+}
+
 export interface UserRecord {
   id: string
   username: string
@@ -77,10 +87,59 @@ const SCHEMA = `
   )
 `
 
+function normalizeBookData(raw: StoredTeachingBook): NormalizedBookData {
+  const data = { ...raw, designs: Array.isArray(raw.designs) ? raw.designs : [] }
+  let changed = false
+
+  if ('cover' in data) {
+    delete data.cover
+    changed = true
+  }
+
+  const selectedId = data.selectedId ?? null
+  const firstDesignId = data.designs[0]?.id ?? null
+  const selectedExists =
+    selectedId !== null && data.designs.some((design) => design.id === selectedId)
+
+  let normalizedSelectedId: TeachingBook['selectedId']
+  if (selectedId === 'cover' || (selectedId !== null && !selectedExists)) {
+    normalizedSelectedId = firstDesignId
+    changed = selectedId !== normalizedSelectedId || changed
+  } else {
+    normalizedSelectedId = selectedId as TeachingBook['selectedId']
+  }
+
+  return {
+    data: {
+      schemaVersion: data.schemaVersion,
+      designs: data.designs,
+      selectedId: normalizedSelectedId,
+      updatedAt: data.updatedAt,
+    },
+    changed,
+  }
+}
+
+function parseBookData(data: string): TeachingBook {
+  return normalizeBookData(JSON.parse(data) as StoredTeachingBook).data
+}
+
+function migrateStoredBooks(db: Database): void {
+  const rows = db.query<{ id: string; data: string }, []>('SELECT id, data FROM books').all()
+
+  for (const row of rows) {
+    const normalized = normalizeBookData(JSON.parse(row.data) as StoredTeachingBook)
+    if (normalized.changed) {
+      db.run('UPDATE books SET data = ? WHERE id = ?', [JSON.stringify(normalized.data), row.id])
+    }
+  }
+}
+
 export function openDb(path: string): Database {
   const db = new Database(path)
   db.run('PRAGMA foreign_keys = ON')
   db.run(SCHEMA)
+  migrateStoredBooks(db)
   return db
 }
 
@@ -93,7 +152,7 @@ export function listBooks(db: Database): BookSummary[] {
     id: row.id,
     name: row.name,
     updatedAt: row.updated_at,
-    lessonCount: (JSON.parse(row.data) as TeachingBook).designs.length,
+    lessonCount: parseBookData(row.data).designs.length,
   }))
 }
 
@@ -124,7 +183,7 @@ export function getBook(db: Database, id: string): BookRecord | null {
     id: row.id,
     name: row.name,
     updatedAt: row.updated_at,
-    data: JSON.parse(row.data) as TeachingBook,
+    data: parseBookData(row.data),
   }
 }
 
@@ -135,7 +194,8 @@ export function saveBookData(db: Database, id: string, data: TeachingBook): Book
   if (!existing) return null
 
   const now = new Date().toISOString()
-  db.run('UPDATE books SET data = ?, updated_at = ? WHERE id = ?', [JSON.stringify(data), now, id])
+  const normalized = normalizeBookData(data as unknown as StoredTeachingBook).data
+  db.run('UPDATE books SET data = ?, updated_at = ? WHERE id = ?', [JSON.stringify(normalized), now, id])
 
   return { id, name: existing.name, updatedAt: now }
 }

server/routes/books.test.ts

@@ -1,7 +1,7 @@
 import { beforeEach, describe, expect, it } from 'bun:test'
 import type { Database } from 'bun:sqlite'
 import { Hono } from 'hono'
-import { createEmptyBook } from '../../src/domain/teachingDesign'
+import { createEmptyBook, createEmptyTeachingDesign } from '../../src/domain/teachingDesign'
 import { openDb } from '../db'
 import { createBooksRouter } from './books'
 
@@ -64,22 +64,22 @@ describe('books routes', () => {
     expect(res.status).toBe(404)
   })
 
-  it('saves book data', async () => {
+  it('saves book data without cover state', async () => {
     const created = await createViaApi('示例整本')
 
     const data = createEmptyBook()
-    data.cover.courseName = 'Web 前端开发'
+    data.designs.push(createEmptyTeachingDesign('1.md'))
 
     const res = await app.request(`/api/books/${created.id}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({ data }),
+      body: JSON.stringify({ data: { ...data, cover: { courseName: '旧课程', teacherName: '旧教师' } } }),
     })
     expect(res.status).toBe(200)
 
     const fetched = await app.request(`/api/books/${created.id}`)
-    const body = (await fetched.json()) as { data: { cover: { courseName: string } } }
+    const body = (await fetched.json()) as { data: Record<string, unknown> }
-    expect(body.data.cover.courseName).toBe('Web 前端开发')
+    expect(body.data).not.toHaveProperty('cover')
   })
 
   it('returns 404 when saving data for a missing book', async () => {

src/components/A4Workspace.test.ts

@@ -0,0 +1,27 @@
+import { mount } from '@vue/test-utils'
+import { describe, expect, it } from 'vitest'
+import { createEmptyTeachingDesign } from '../domain/teachingDesign'
+import A4Workspace from './A4Workspace.vue'
+
+describe('A4Workspace', () => {
+  it('renders a selected lesson without cover state', () => {
+    const design = createEmptyTeachingDesign('1.md')
+    design.topic = 'CSS 弹性布局'
+
+    const wrapper = mount(A4Workspace, {
+      props: { selectedDesign: design },
+    })
+
+    expect(Object.keys(wrapper.props()).sort()).toEqual(['selectedDesign'])
+    expect(wrapper.find('.cover-page').exists()).toBe(false)
+    expect(wrapper.find('.teaching-design-page').exists()).toBe(true)
+  })
+
+  it('renders no page when no lesson is selected', () => {
+    const wrapper = mount(A4Workspace, {
+      props: { selectedDesign: null },
+    })
+
+    expect(wrapper.find('.page').exists()).toBe(false)
+  })
+})

src/components/A4Workspace.vue

@@ -1,16 +1,12 @@
 <script setup lang="ts">
-import type { BookCover, TeachingDesign } from '../domain/teachingDesign'
+import type { TeachingDesign } from '../domain/teachingDesign'
-import CoverPage from './CoverPage.vue'
 import TeachingDesignPage from './TeachingDesignPage.vue'
 
 defineProps<{
-  cover: BookCover
-  selectedId: string
   selectedDesign: TeachingDesign | null
 }>()
 
 const emit = defineEmits<{
-  'update:cover': [patch: Partial<BookCover>]
   'update:design': [design: TeachingDesign]
 }>()
 </script>
@@ -18,16 +14,8 @@ const emit = defineEmits<{
 <template>
   <div class="a4-workspace">
     <div class="a4-paper">
-      <CoverPage
-        v-if="selectedId === 'cover'"
-        :course-name="cover.courseName"
-        :teacher-name="cover.teacherName"
-        :editable="true"
-        @update:course-name="emit('update:cover', { courseName: $event })"
-        @update:teacher-name="emit('update:cover', { teacherName: $event })"
-      />
       <TeachingDesignPage
-        v-else-if="selectedDesign"
+        v-if="selectedDesign"
         :design="selectedDesign"
         :editable="true"
         @update:design="emit('update:design', $event)"

src/components/CoverPage.vue

@@ -1,40 +0,0 @@
-<script setup lang="ts">
-import EditableText from './EditableText.vue'
-
-defineProps<{
-  courseName: string
-  teacherName: string
-  editable: boolean
-}>()
-
-defineEmits<{
-  'update:courseName': [value: string]
-  'update:teacherName': [value: string]
-}>()
-</script>
-
-<template>
-  <section class="page cover-page">
-    <h1 class="cover-title">教学设计</h1>
-    <div class="cover-field">
-      <span class="cover-field-label">课程名称</span>
-      <EditableText
-        class="cover-field-value"
-        :model-value="courseName"
-        label="课程名称"
-        :editable="editable"
-        @update:model-value="$emit('update:courseName', $event)"
-      />
-    </div>
-    <div class="cover-field">
-      <span class="cover-field-label">教师姓名</span>
-      <EditableText
-        class="cover-field-value"
-        :model-value="teacherName"
-        label="教师姓名"
-        :editable="editable"
-        @update:model-value="$emit('update:teacherName', $event)"
-      />
-    </div>
-  </section>
-</template>

src/components/LessonSidebar.test.ts

@@ -7,7 +7,7 @@ describe('LessonSidebar', () => {
   it('emits a move when one lesson is dropped on another', async () => {
     const designs = [createEmptyTeachingDesign('1.md'), createEmptyTeachingDesign('2.md')]
     const wrapper = mount(LessonSidebar, {
-      props: { designs, selectedId: designs[0]?.id ?? 'cover' },
+      props: { designs, selectedId: designs[0]?.id ?? null },
     })
 
     await wrapper.get('[data-index="0"]').trigger('dragstart')
@@ -15,4 +15,14 @@ describe('LessonSidebar', () => {
 
     expect(wrapper.emitted('move')?.[0]).toEqual([0, 1])
   })
+
+  it('does not render a cover navigation item', () => {
+    const designs = [createEmptyTeachingDesign('1.md')]
+    const wrapper = mount(LessonSidebar, {
+      props: { designs, selectedId: null },
+    })
+
+    expect(wrapper.text()).not.toContain('封面')
+    expect(wrapper.find('.lesson-sidebar-cover').exists()).toBe(false)
+  })
 })

src/components/LessonSidebar.vue

@@ -4,11 +4,11 @@ import type { DesignId, TeachingDesign } from '../domain/teachingDesign'
 
 defineProps<{
   designs: TeachingDesign[]
-  selectedId: 'cover' | DesignId
+  selectedId: DesignId | null
 }>()
 
 const emit = defineEmits<{
-  select: [id: 'cover' | DesignId]
+  select: [id: DesignId]
   remove: [id: DesignId]
   move: [from: number, to: number]
 }>()
@@ -29,15 +29,6 @@ function onDrop(targetIndex: number): void {
 
 <template>
   <nav class="lesson-sidebar" aria-label="教案目录">
-    <button
-      type="button"
-      class="lesson-sidebar-item lesson-sidebar-cover"
-      :class="{ 'lesson-sidebar-item--active': selectedId === 'cover' }"
-      @click="emit('select', 'cover')"
-    >
-      封面
-    </button>
-
     <ul class="lesson-sidebar-list">
       <li
         v-for="(design, index) in designs"

src/components/WorkspaceView.test.ts

@@ -74,6 +74,19 @@ describe('WorkspaceView', () => {
     expect(wrapper.text()).toContain('CSS 弹性布局')
   })
 
+  it('does not render cover navigation when lessons exist', async () => {
+    const data = createEmptyBook()
+    const design = createEmptyTeachingDesign('1.md')
+    data.designs.push(design)
+    data.selectedId = design.id
+    mockBook(data)
+
+    const wrapper = mount(WorkspaceView, { props: { bookId: 'b1' } })
+    await flushPromises()
+
+    expect(wrapper.text()).not.toContain('封面')
+  })
+
   it('clears the lessons after confirmation', async () => {
     const data = createEmptyBook()
     data.designs.push(createEmptyTeachingDesign('1.md'))

src/components/WorkspaceView.vue

@@ -32,7 +32,6 @@ const {
   selectPage,
   moveDesign,
   removeDesign,
-  updateCover,
   updateDesign,
   clearBook,
   generateLesson,
@@ -299,10 +298,7 @@ function closeFixDialog(): void {
             @move="moveDesign"
           />
           <A4Workspace
-            :cover="book.cover"
-            :selected-id="book.selectedId"
             :selected-design="selectedDesign"
-            @update:cover="updateCover"
             @update:design="handleDesignUpdate"
           />
         </div>

src/composables/useTeachingBook.test.ts

@@ -10,15 +10,22 @@ function mockGetBook(data: TeachingBook, id = 'b1'): void {
   vi.mocked(booksApi.getBook).mockResolvedValue({ id, name: '示例整本', updatedAt: data.updatedAt, data })
 }
 
+function createBookWithDesign(filename = '1.md'): { data: TeachingBook; design: ReturnType<typeof createEmptyTeachingDesign> } {
+  const data = createEmptyBook()
+  const design = createEmptyTeachingDesign(filename)
+  data.designs.push(design)
+  data.selectedId = design.id
+  return { data, design }
+}
+
 describe('useTeachingBook', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     vi.useFakeTimers()
   })
 
-  it('loads the book from the API', async () => {
+  it('loads the book from the API without cover state', async () => {
-    const data = createEmptyBook()
+    const { data } = createBookWithDesign()
-    data.cover.courseName = 'Web 前端开发'
     mockGetBook(data)
 
     const store = useTeachingBook('b1')
@@ -26,7 +33,8 @@ describe('useTeachingBook', () => {
 
     expect(booksApi.getBook).toHaveBeenCalledWith('b1')
     expect(store.loadStatus.value).toBe('loaded')
-    expect(store.book.value.cover.courseName).toBe('Web 前端开发')
+    expect(store.book.value).not.toHaveProperty('cover')
+    expect(store.book.value.selectedId).toBe(data.selectedId)
   })
 
   it('sets loadStatus to error when loading fails', async () => {
@@ -82,13 +90,16 @@ describe('useTeachingBook', () => {
   })
 
   it('autosaves the book via the API after the debounce delay', async () => {
-    mockGetBook(createEmptyBook())
+    const { data, design } = createBookWithDesign()
+    mockGetBook(data)
     vi.mocked(booksApi.updateBook).mockResolvedValue({ id: 'b1', name: '示例整本', updatedAt: 'later' })
 
     const store = useTeachingBook('b1')
     await flushPromises()
 
-    store.updateCover({ courseName: '新课程名' })
+    store.updateDesign(design.id, (current) => {
+      current.title = '新课程名'
+    })
     await vi.advanceTimersByTimeAsync(300)
 
     expect(booksApi.updateBook).toHaveBeenCalledWith('b1', store.book.value)
@@ -96,13 +107,16 @@ describe('useTeachingBook', () => {
   })
 
   it('sets saveStatus to error when autosave fails', async () => {
-    mockGetBook(createEmptyBook())
+    const { data, design } = createBookWithDesign()
+    mockGetBook(data)
     vi.mocked(booksApi.updateBook).mockRejectedValue(new Error('保存失败。'))
 
     const store = useTeachingBook('b1')
     await flushPromises()
 
-    store.updateCover({ courseName: '新课程名' })
+    store.updateDesign(design.id, (current) => {
+      current.title = '新课程名'
+    })
     await vi.advanceTimersByTimeAsync(300)
 
     expect(store.saveStatus.value).toBe('error')
@@ -139,10 +153,8 @@ describe('useTeachingBook', () => {
     expect(store.book.value.designs).toHaveLength(0)
   })
 
-  it('clearBook empties designs but keeps the cover', async () => {
+  it('clearBook empties designs and clears selection', async () => {
-    const data = createEmptyBook()
+    const { data } = createBookWithDesign()
-    data.cover.courseName = 'Web 前端开发'
-    data.designs.push(createEmptyTeachingDesign('1.md'))
     mockGetBook(data)
 
     const store = useTeachingBook('b1')
@@ -151,7 +163,22 @@ describe('useTeachingBook', () => {
     store.clearBook()
 
     expect(store.book.value.designs).toEqual([])
-    expect(store.book.value.cover.courseName).toBe('Web 前端开发')
+    expect(store.book.value).not.toHaveProperty('cover')
-    expect(store.book.value.selectedId).toBe('cover')
+    expect(store.book.value.selectedId).toBeNull()
+  })
+
+  it('selects null after removing the last selected lesson', async () => {
+    const { data, design } = createBookWithDesign()
+    mockGetBook(data)
+
+    const store = useTeachingBook('b1')
+    await flushPromises()
+
+    store.removeDesign(design.id)
+    await flushPromises()
+
+    expect(store.book.value.designs).toEqual([])
+    expect(store.book.value.selectedId).toBeNull()
+    expect(store.selectedDesign.value).toBeNull()
   })
 })

src/composables/useTeachingBook.ts

@@ -1,7 +1,6 @@
 import { nextTick, ref, watch, type Ref } from 'vue'
 import {
   createEmptyBook,
-  type BookCover,
   type DesignId,
   type TeachingBook,
   type TeachingDesign,
@@ -38,10 +37,9 @@ export interface TeachingBookStore {
   warningCount: Ref<number>
   importFiles: (files: readonly File[], strategy: DuplicateStrategy) => Promise<ImportResult>
   detectDuplicates: (files: readonly File[]) => string[]
-  selectPage: (id: 'cover' | DesignId) => void
+  selectPage: (id: DesignId) => void
   moveDesign: (from: number, to: number) => void
   removeDesign: (id: DesignId) => void
-  updateCover: (patch: Partial<BookCover>) => void
   updateDesign: (id: DesignId, updater: (design: TeachingDesign) => void) => void
   clearBook: () => void
   generateLesson: (topic: string) => Promise<GenerateLessonResult>
@@ -67,7 +65,7 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
     const current = book.value
     hasDesigns.value = current.designs.length > 0
     selectedDesign.value =
-      current.selectedId === 'cover'
+      current.selectedId === null
         ? null
         : current.designs.find((design) => design.id === current.selectedId) ?? null
     warningCount.value = current.designs.reduce(
@@ -176,7 +174,7 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
       }
     }
 
-    if (imported > 0 && book.value.selectedId === 'cover' && book.value.designs.length > 0) {
+    if (imported > 0 && book.value.selectedId === null && book.value.designs.length > 0) {
       book.value.selectedId = book.value.designs[0]!.id
     }
 
@@ -187,7 +185,7 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
     return { imported, failed, duplicates }
   }
 
-  function selectPage(id: 'cover' | DesignId): void {
+  function selectPage(id: DesignId): void {
     book.value.selectedId = id
   }
 
@@ -210,17 +208,12 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
     designs.splice(index, 1)
 
     if (book.value.selectedId === id) {
-      book.value.selectedId = designs[index]?.id ?? designs[index - 1]?.id ?? 'cover'
+      book.value.selectedId = designs[index]?.id ?? designs[index - 1]?.id ?? null
     }
 
     touch()
   }
 
-  function updateCover(patch: Partial<BookCover>): void {
-    Object.assign(book.value.cover, patch)
-    touch()
-  }
-
   function updateDesign(id: DesignId, updater: (design: TeachingDesign) => void): void {
     const design = book.value.designs.find((candidate) => candidate.id === id)
     if (!design) {
@@ -232,7 +225,7 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
 
   function clearBook(): void {
     book.value.designs = []
-    book.value.selectedId = 'cover'
+    book.value.selectedId = null
     touch()
   }
 
@@ -286,7 +279,6 @@ export function useTeachingBook(bookId: string): TeachingBookStore {
     selectPage,
     moveDesign,
     removeDesign,
-    updateCover,
     updateDesign,
     clearBook,
     generateLesson,

src/domain/teachingDesign.test.ts

@@ -53,24 +53,22 @@ describe('createEmptyTeachingDesign', () => {
 })
 
 describe('createEmptyBook', () => {
-  it('creates the schema defaults with cover selected and an ISO timestamp', () => {
+  it('creates the schema defaults with no selected page and an ISO timestamp', () => {
     const book = createEmptyBook()
 
     expect(book.schemaVersion).toBe(BOOK_SCHEMA_VERSION)
-    expect(book.selectedId).toBe('cover')
+    expect(book.selectedId).toBeNull()
+    expect(book).not.toHaveProperty('cover')
     expect(new Date(book.updatedAt).toISOString()).toBe(book.updatedAt)
   })
 
-  it('creates independent cover and design collections', () => {
+  it('creates independent design collections', () => {
     const first = createEmptyBook()
     const second = createEmptyBook()
 
-    first.cover.courseName = 'Changed'
     first.designs.push(createEmptyTeachingDesign('1.md'))
 
-    expect(first.cover).not.toBe(second.cover)
     expect(first.designs).not.toBe(second.designs)
-    expect(second.cover.courseName).toBe('')
     expect(second.designs).toEqual([])
   })
 })
@@ -79,7 +77,7 @@ describe('domain types', () => {
   it('uses branded string design IDs and literal schema versions', () => {
     expectTypeOf<DesignId>().toExtend<string>()
     expectTypeOf<TeachingDesign['id']>().toEqualTypeOf<DesignId>()
-    expectTypeOf<TeachingBook['selectedId']>().toEqualTypeOf<'cover' | DesignId>()
+    expectTypeOf<TeachingBook['selectedId']>().toEqualTypeOf<DesignId | null>()
     expectTypeOf<TeachingBook['schemaVersion']>().toEqualTypeOf<
       typeof BOOK_SCHEMA_VERSION
     >()

src/domain/teachingDesign.ts

@@ -50,16 +50,10 @@ export interface TeachingDesign {
   warnings: ParseWarning[]
 }
 
-export interface BookCover {
-  courseName: string
-  teacherName: string
-}
-
 export interface TeachingBook {
   schemaVersion: typeof BOOK_SCHEMA_VERSION
-  cover: BookCover
   designs: TeachingDesign[]
-  selectedId: 'cover' | DesignId
+  selectedId: DesignId | null
   updatedAt: string
 }
 
@@ -104,9 +98,8 @@ export function createEmptyTeachingDesign(filename: string): TeachingDesign {
 export function createEmptyBook(): TeachingBook {
   return {
     schemaVersion: BOOK_SCHEMA_VERSION,
-    cover: { courseName: '', teacherName: '' },
     designs: [],
-    selectedId: 'cover',
+    selectedId: null,
     updatedAt: new Date().toISOString(),
   }
 }

src/style.css

@@ -238,17 +238,6 @@ input {
   flex-direction: column;
 }
 
-.lesson-sidebar-cover {
-  border: none;
-  border-bottom: 1px solid var(--line);
-  background: none;
-  text-align: left;
-  padding: 12px 16px;
-  font-weight: 600;
-  color: var(--green-700);
-  cursor: pointer;
-}
-
 .lesson-sidebar-list {
   list-style: none;
   margin: 0;
@@ -346,41 +335,6 @@ input {
   box-shadow: none;
 }
 
-/* Cover page */
-.cover-page {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  text-align: center;
-  gap: 24px;
-}
-
-.cover-title {
-  font-size: 40px;
-  font-weight: 700;
-  letter-spacing: 0.2em;
-  color: var(--green-700);
-  margin: 0;
-}
-
-.cover-field {
-  display: flex;
-  align-items: center;
-  gap: 12px;
-  font-size: 18px;
-}
-
-.cover-field-label {
-  color: var(--muted);
-}
-
-.cover-field-value {
-  min-width: 12em;
-  text-align: left;
-  border-bottom: 1px solid var(--line);
-}
-
 /* Teaching design page */
 .teaching-design-page {
   display: flex;