feat: add Vue2 exercises for dynamic styles, lifecycle methods, component communication, and course management dashboard

- Implement dynamic styles and event handling in Vue2 with a card component.
- Create lifecycle methods exercise to simulate async data loading and instance destruction.
- Develop a component communication exercise with props, events, and slots.
- Build a comprehensive course management dashboard with filtering, statistics, and component interactions.

07-vue2/06-class-style-and-event/README.md

@@ -0,0 +1,27 @@
+# 练习 6：动态类名、样式和事件
+
+## 目标
+
+学会让组件状态直接影响样式和交互反馈。
+
+## 你要练什么
+
+- `:class`
+- `:style`
+- `v-on`
+- 点击切换状态
+
+## 任务
+
+请基于页面结构完成以下操作：
+
+- 点击卡片切换激活状态
+- 根据激活状态切换类名
+- 根据进度值动态改变进度条宽度
+
+## 文件
+
+- [starter.html](/Users/lijiaqing/home/wwwroot/front-end-example/07-vue2/06-class-style-and-event/starter.html)
+- [starter.js](/Users/lijiaqing/home/wwwroot/front-end-example/07-vue2/06-class-style-and-event/starter.js)
+- [answer.html](/Users/lijiaqing/home/wwwroot/front-end-example/07-vue2/06-class-style-and-event/answer.html)
+- [answer.js](/Users/lijiaqing/home/wwwroot/front-end-example/07-vue2/06-class-style-and-event/answer.js)