## ADDED Requirements

### Requirement: Three-layer page navigation
The SpeakingPanel SHALL manage a three-layer page structure with breadcrumb navigation: Layer 1 (英语学科主页) → Layer 2 (口语子页面) → Layer 3 (配置页).

#### Scenario: Navigate from Layer 1 to Layer 2
- **WHEN** teacher clicks the "口语" exercise type on Layer 1
- **THEN** the panel transitions to Layer 2 (口语子页面)
- **THEN** the breadcrumb shows "英语学科 > 口语"

#### Scenario: Navigate back via breadcrumb
- **WHEN** teacher clicks "英语学科" in the breadcrumb on Layer 2
- **THEN** the panel returns to Layer 1

### Requirement: Curriculum cascading selectors
Layer 1 SHALL display three cascading dropdown selectors for textbook, grade, and unit, loaded from `curriculum.json`.

#### Scenario: Select textbook, grade, and unit
- **WHEN** teacher selects a textbook, grade, and unit from the dropdowns
- **THEN** the unit info card updates to show the selected unit's title and description

### Requirement: Unit info card
Layer 1 SHALL display a card showing the selected unit's title and learning description.

#### Scenario: View unit info
- **WHEN** a unit is selected
- **THEN** the card displays the unit's title (e.g., "Going to school") and its description

### Requirement: Exercise type grid
Layer 1 SHALL display a grid of exercise types: 口语, 听力, 阅读, 写作.

#### Scenario: Click speaking exercise type
- **WHEN** teacher clicks "口语"
- **THEN** the panel navigates to Layer 2

#### Scenario: Click non-speaking exercise type
- **WHEN** teacher clicks "听力", "阅读", or "写作"
- **THEN** nothing happens (not implemented yet, visually disabled or show "coming soon")

### Requirement: Creation mode switch on Layer 2
Layer 2 SHALL support creation mode switching as implemented in the demo SpeakingPanelV2.tsx.

#### Scenario: Switch between creation modes
- **WHEN** teacher switches between 智能推荐, AI生成, and 手动创建
- **THEN** the Layer 2 content updates to show the corresponding view

### Requirement: Smart recommendation cards
Layer 2 in 智能推荐 mode SHALL display recommendation cards from `topicDiscussionTasks.json`, filtered by selected unit ID.

#### Scenario: View recommendations for a unit
- **WHEN** Unit 2 is selected and 智能推荐 mode is active
- **THEN** the panel displays 4 topic discussion recommendation cards with titleZh, subtitle, difficulty, rounds, durationMinutes

#### Scenario: Click a recommendation card
- **WHEN** teacher clicks a recommendation card
- **THEN** the panel navigates to Layer 3 (TopicDiscussionConfig) pre-filled with the card's vocabulary and sentences

#### Scenario: No recommendations for a unit
- **WHEN** a unit with no recommendation data is selected
- **THEN** the panel displays an empty state message

### Requirement: AI generation UI shell
Layer 2 in AI生成 mode SHALL display the AI generation form UI without backend functionality.

#### Scenario: View AI generation form
- **WHEN** teacher switches to AI生成 mode
- **THEN** the AI generation form is displayed (UI only, no actual generation)

### Requirement: Manual creation
Layer 2 in 手动创建 mode SHALL navigate directly to the TopicDiscussionConfig with default/empty values.

#### Scenario: Enter manual creation
- **WHEN** teacher switches to 手动创建 mode
- **THEN** the panel navigates to Layer 3 (TopicDiscussionConfig) with empty/default configuration
