添加404界面，优化homeview代码可读性

tonecn/src/views/NotFound.vue

@@ -0,0 +1,38 @@
+<script setup lang='ts'>
+import { onMounted, onUnmounted, ref } from 'vue';
+const containerHeight = ref('800px');
+onMounted(async () => {
+    document.title = '404 不存在的页面';
+    containerHeight.value = window.innerHeight > 500 ? window.innerHeight -85 + 'px' : '390px';
+})
+onUnmounted(() => {
+    document.title = '特恩(TONE)';
+})
+</script>
+<template>
+    <div class="bcc"></div>
+    <div class="content-container">
+        <el-empty id="404-notfound-el-empty" style="margin-bottom: 200px;" description="404 不存在的页面" />
+    </div>
+</template>
+<style scoped>
+.bcc {
+    position: fixed;
+    z-index: -1;
+    background-color: #f6f8f9;
+    left: 0;
+    top: 0;
+    width: 100%;
+    height: 100%;
+}
+
+.content-container {
+    display: flex;
+    flex-direction: column;
+    justify-content: center;
+    max-width: 600px;
+    margin: 0px auto;
+    padding: 0 20px;
+    height: v-bind(containerHeight);
+}
+</style>