feat: 添加 UnoCSS 样式到主要组件

- AppLayout.vue: 添加渐变背景和响应式布局
- App.vue: 美化主页面，包含卡片布局和绿色主题按钮
- index.page.vue: 创建彩色渐变的英雄区块，包含动画效果和交互卡片

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/layouts/naive-ui/AppLayout.vue

@@ -1,9 +1,10 @@
 <script setup lang="ts"></script>
 
 <template>
-  <div class="app-layout">
-    <div>AppLayout</div>
-    <router-view />
+  <div class="app-layout min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100">
+    <main class="max-w-7xl mx-auto px-4 py-8">
+      <router-view />
+    </main>
   </div>
 </template>