feat(docs): 添加自定义404页面组件

- 创建 NotFound.vue 组件实现404页面功能
- 在主题配置中注册并集成自定义404页面
- 实现中英文双语支持和自动重定向功能
- 添加倒计时自动跳转到首页的功能
- 设计美观的404错误页面样式和布局
- 提供相关文档页面链接建议和返回首页按钮

docs/.vitepress/theme/NotFound.vue

@@ -0,0 +1,167 @@
+<script setup lang="ts">
+import { ref, onMounted, onUnmounted, computed } from 'vue'
+import { useData, useRouter, withBase } from 'vitepress'
+
+const { lang } = useData()
+const router = useRouter()
+
+const isZh = computed(() => lang.value === 'zh-CN')
+
+const countdown = ref(5)
+let timer: number | null = null
+
+const goHome = () => {
+  if (timer) clearInterval(timer)
+  router.go(withBase(isZh.value ? '/zh-CN/' : '/en/'))
+}
+
+onMounted(() => {
+  timer = window.setInterval(() => {
+    countdown.value--
+    if (countdown.value <= 0) {
+      goHome()
+    }
+  }, 1000)
+})
+
+onUnmounted(() => {
+  if (timer) clearInterval(timer)
+})
+</script>
+
+<template>
+  <div class="not-found-container">
+    <h1 class="error-code">404</h1>
+
+    <h2 class="error-title">
+      {{ isZh ? '页面未找到' : 'Page Not Found' }}
+    </h2>
+
+    <p class="error-message">
+      <template v-if="isZh">
+        您访问的页面不存在。
+      </template>
+      <template v-else>
+        The page you are looking for does not exist.
+      </template>
+    </p>
+
+    <p class="countdown-text">
+      <template v-if="isZh">
+        <span class="countdown-number">{{ countdown }}</span> 秒后自动跳转
+      </template>
+      <template v-else>
+        Auto redirecting in <span class="countdown-number">{{ countdown }}</span> seconds
+      </template>
+    </p>
+
+    <div class="suggestions">
+      <h3>📚 {{ isZh ? '您可能想访问：' : 'You might be looking for:' }}</h3>
+      <ul v-if="isZh">
+        <li>→ <a :href="withBase('/zh-CN/getting-started/installation')">安装配置</a></li>
+        <li>→ <a :href="withBase('/zh-CN/getting-started/quick-start')">快速开始</a></li>
+        <li>→ <a :href="withBase('/zh-CN/core/overview')">Core 核心框架</a></li>
+        <li>→ <a :href="withBase('/zh-CN/tutorials/basic-tutorial')">基础教程</a></li>
+      </ul>
+      <ul v-else>
+        <li>→ <a :href="withBase('/en/getting-started/installation')">Installation</a></li>
+        <li>→ <a :href="withBase('/en/getting-started/quick-start')">Quick Start</a></li>
+        <li>→ <a :href="withBase('/en/core/overview')">Core Overview</a></li>
+        <li>→ <a :href="withBase('/en/tutorials/basic-tutorial')">Basic Tutorial</a></li>
+      </ul>
+    </div>
+
+    <div class="action-buttons">
+      <button class="btn btn-primary" @click="goHome">
+        {{ isZh ? '返回首页' : 'Go to Homepage' }}
+      </button>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.not-found-container {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  min-height: 60vh;
+  text-align: center;
+  padding: 20px;
+}
+
+.error-code {
+  font-size: 120px;
+  font-weight: bold;
+  background: linear-gradient(120deg, #3451b2 0%, #6366f1 100%);
+  -webkit-background-clip: text;
+  -webkit-text-fill-color: transparent;
+  background-clip: text;
+  margin: 0;
+  line-height: 1;
+}
+
+.error-title {
+  font-size: 32px;
+  margin: 20px 0 10px;
+  color: var(--vp-c-text-1);
+}
+
+.error-message {
+  font-size: 18px;
+  color: var(--vp-c-text-2);
+  margin-bottom: 10px;
+}
+
+.countdown-text {
+  font-size: 16px;
+  color: var(--vp-c-text-3);
+  margin: 20px 0;
+}
+
+.countdown-number {
+  color: #3451b2;
+  font-weight: bold;
+  font-size: 20px;
+}
+
+.action-buttons {
+  display: flex;
+  gap: 16px;
+  margin-top: 30px;
+}
+
+.btn {
+  padding: 12px 24px;
+  border-radius: 8px;
+  text-decoration: none;
+  font-weight: 500;
+  transition: all 0.3s;
+  cursor: pointer;
+  border: none;
+  font-size: 16px;
+}
+
+.btn-primary {
+  background: #3451b2;
+  color: white;
+}
+
+.btn-primary:hover {
+  background: #2841a0;
+  transform: translateY(-2px);
+}
+
+.suggestions {
+  margin-top: 24px;
+}
+
+.suggestions ul {
+  list-style: none;
+  padding: 0;
+}
+
+.suggestions li {
+  margin: 6px 0;
+}
+</style>

docs/.vitepress/theme/index.ts

@@ -3,12 +3,14 @@ import { h } from 'vue'
 import type { Theme } from 'vitepress'
 import DefaultTheme from 'vitepress/theme'
 import './style.css'
+import NotFound from './NotFound.vue'
 
 export default {
   extends: DefaultTheme,
   Layout: () => {
     return h(DefaultTheme.Layout, null, {
       // https://vitepress.dev/guide/extending-default-theme#layout-slots
+      "not-found": () => h(NotFound)
     })
   },
   enhanceApp({ app, router, siteData }) {