## ADDED Requirements

### Requirement: Topic discussion configuration
The TopicDiscussionConfig SHALL allow teacher to configure a topic discussion exercise, matching the demo `TopicDiscussionConfig.tsx` implementation.

#### Scenario: Set discussion topic
- **WHEN** teacher opens TopicDiscussionConfig
- **THEN** teacher can input a discussion topic text

### Requirement: Learning goals - vocabulary
The TopicDiscussionConfig SHALL allow teacher to manage practice vocabulary.

#### Scenario: Add vocabulary
- **WHEN** teacher clicks the add button and types a word
- **THEN** the word is added as a tag to the vocabulary list

#### Scenario: Remove vocabulary
- **WHEN** teacher clicks the remove button on a vocabulary tag
- **THEN** the word is removed from the vocabulary list

#### Scenario: Batch paste vocabulary and sentences
- **WHEN** teacher clicks the batch paste button
- **THEN** a dialog opens allowing teacher to paste multiple vocabulary items and sentences at once

### Requirement: Learning goals - sentences
The TopicDiscussionConfig SHALL allow teacher to manage practice sentences.

#### Scenario: Add sentence
- **WHEN** teacher clicks the add button and types a sentence
- **THEN** the sentence is added to the sentence list

#### Scenario: Edit sentence
- **WHEN** teacher double-clicks a sentence
- **THEN** the sentence becomes editable inline

#### Scenario: Remove sentence
- **WHEN** teacher clicks the remove button on a sentence
- **THEN** the sentence is removed from the list

### Requirement: Practice mode configuration
The TopicDiscussionConfig SHALL allow teacher to set practice mode (time-limited or round-limited) with a slider.

#### Scenario: Set time-limited mode
- **WHEN** teacher selects "限制时长" mode
- **THEN** a slider appears for setting duration (1-60 minutes)

#### Scenario: Set round-limited mode
- **WHEN** teacher selects "限制轮次" mode
- **THEN** a slider appears for setting rounds (1-60 rounds)

### Requirement: Show learning report toggle
The TopicDiscussionConfig SHALL allow teacher to toggle whether to show the learning report to students.

#### Scenario: Toggle learning report
- **WHEN** teacher toggles the "展示学习报告" switch
- **THEN** the report display setting is updated

### Requirement: Advanced configuration - assistance
The TopicDiscussionConfig SHALL provide an expandable advanced configuration section with assistance toggles.

#### Scenario: Configure assistance options
- **WHEN** teacher expands "高级配置" and views "辅助功能"
- **THEN** teacher can toggle: 显示英文, 任务提示, 卡顿提示

### Requirement: Advanced configuration - evaluation
The TopicDiscussionConfig SHALL provide evaluation dimension checkboxes and score mode selection.

#### Scenario: Configure evaluation dimensions
- **WHEN** teacher views "评估详情"
- **THEN** teacher can toggle dimensions: 准确度, 流畅度, 完整度, 节奏韵律

#### Scenario: Configure score mode
- **WHEN** teacher views "评分方式"
- **THEN** teacher can select: 字母评分 (A-D), 量化评分 (0-100), or 仅展示评语

### Requirement: Apply configuration
The TopicDiscussionConfig SHALL have an "应用配置" button that triggers tool integration.

#### Scenario: Apply configuration
- **WHEN** teacher clicks "应用配置"
- **THEN** the system calls `parentWindow.addTool(77)` to notify the parent application
