diff --git a/src/components/AppIcon/index.vue b/src/components/AppIcon/index.vue
index 3ed3e97..11f4f52 100644
--- a/src/components/AppIcon/index.vue
+++ b/src/components/AppIcon/index.vue
@@ -1,54 +1,65 @@
 <template>
-  <i v-bind="$attrs" style="display: inline-flex">
-    <el-icon v-if="iconType === 'ElIcon'" v-bind="iconProp">
-      <component :is="iconName" />
+  <i v-bind="$attrs" class="app-icon" :class="{ text }">
+    <el-icon v-if="isElIcon" :color="color" :size="parseInt(size)">
+      <component :is="icon" />
     </el-icon>
     <svg v-else v-bind="iconProp">
       <use :xlink:href.attr="iconName" />
     </svg>
+    <span v-if="text">{{ text }}</span>
   </i>
 </template>
 
-<script>
+<script setup>
+import { ElIcon } from 'element-plus'
+
 /**
- * <app-icon icon="el-icon-right" />      el-开头将渲染成 <i/> el图标支持小驼峰和中划线分割命名
- * <app-icon icon="github" size="32" />   其他则渲染成 <svg>
+ * @example <app-icon icon="el-icon-right" />      el-开头将渲染成 <i/> el图标支持小驼峰和中划线分割命名
+ * <app-icon icon="github" size="32" />   其他则渲染成  <svg>
  *
  * 附： 动态组件 <component :is="xxx" />模板编译的结果：_resolveDynamicComponent(xxx)
  * 该函数被定义在 runtime-core/src/helpers/resolveAssets.ts，内部调用app.context获取对应已注册的组件
  * component 内置组件除了支持 is 绑定之外，也支持其他属性绑定和事件绑定
+ *
+ * 如果svg标签的path标签已设置fill="color" 则该path的颜色也不会被更改
  */
-import { ElIcon } from 'element-plus'
+const props = defineProps({
+  icon: { type: String, required: true },
+  size: { default: 16 },
+  color: { default: 'inherit' },
+  text: { type: [String, Number] },
+})
 
-export default {
-  name: 'AppIcon',
-  components: { ElIcon },
-  props: {
-    icon: { type: String, required: true },
-    // 如果svg标签的path标签已设置fill="color" 则该path的颜色也不会被更改
-    color: { type: String },
-    size: { default: 16 },
-  },
-  setup(props) {
-    const { icon, color, size } = props
-    let iconType, iconName, iconProp
-    if (icon.startsWith('el-icon-') || icon.startsWith('elIcon')) {
-      iconType = 'ElIcon'
-      iconName = icon
-      iconProp = { color, size: Number(size) }
-    } else {
-      // 根据名字生成id使用svg>symbol里的svg标签(已提前注入到index.html中body下的svg标签)
-      iconType = 'Custom'
-      iconName = '#icon-' + icon
-      const sizePx = size + 'px'
-      const style = { width: sizePx, height: sizePx }
-      if (color) {
-        style.color = color
-        style.fill = 'currentColor'
-      }
-      iconProp = { style }
-    }
-    return { iconType, iconName, iconProp }
-  },
+const isElIcon = /^el-?/i.test(props.icon)
+
+let iconName, iconProp
+
+// 如果不是el-icon,则使用svg sprites图标，以 #icon- 为id前缀进行引用
+if (!isElIcon) {
+  iconName = '#icon-' + props.icon
+  const size = isNaN(props.size) ? props.size : props.size + 'px'
+  const style = { width: size, height: size }
+  if (props.color) {
+    style.color = props.color
+    style.fill = 'currentColor'
+  }
+  iconProp = { style }
 }
 </script>
+
+<style lang="scss">
+@import '/src/styles/variables';
+
+.app-icon {
+  display: inline-flex;
+}
+
+.app-icon.text {
+  align-items: center;
+  cursor: pointer;
+}
+
+.app-icon.text:hover {
+  color: #1d7dfa;
+}
+</style>
diff --git a/src/directives/default-img.js b/src/directives/default-img.js
new file mode 100644
index 0000000..8529798
--- /dev/null
+++ b/src/directives/default-img.js
@@ -0,0 +1,59 @@
+import defaultAvatar from '/src/assets/images/dio.jpg'
+import defaultBackground from '/src/assets/images/cute.jpg'
+import { getStrColor } from '../utils/process'
+
+/**
+ * 项目难点标记：检测图片存在，如果不存在则用用户的昵称的首字符作为头像,绘制svg
+ * 检测图片是否存在
+ * @param url
+ */
+const imageIsExist = function (url) {
+  return new Promise((resolve) => {
+    let img = new Image()
+    img.src = url
+    img.onload = () => {
+      if (img.complete === true) {
+        resolve(true)
+        img = null
+      }
+    }
+    img.onerror = () => {
+      resolve(false)
+      img = null
+    }
+  })
+}
+
+function genSvgImg(text, color, size = 36) {
+  text = text.substring(0, 1)
+  color = encodeURIComponent(color)
+  return `data:image/svg+xml;utf8,
+<svg viewBox="0 0 ${size} ${size}" xmlns="http://www.w3.org/2000/svg">
+  <rect width="100%" height="100%" fill="${color}"/>
+  <text x="50%" y="53%" text-anchor="middle" dominant-baseline="middle" fill='%23f1f1f1'>${text}</text>
+</svg>`
+}
+
+/**
+ * 当图片加载失败时，显示默认图片
+ * 参数可选：'avatar' | 'background' | string
+ * <img :src="xxxx" v-default-img.avatar />
+ */
+export default async function defaultImg(el, binding) {
+  // 需要显示默认图片(当图片原本的src属性有错时)的类型
+  const { value, modifiers } = binding
+  // 图片原本的src
+  const realURL = el.src
+  // 当原本图片不存在时，根据参数返回不同的图片url
+  const exist = await imageIsExist(realURL)
+  if (exist) return // 图片可正常加载，不做任何处理
+  if (value) {
+    el.setAttribute('src', genSvgImg(value, getStrColor(value)))
+  } else if (modifiers.avatar) {
+    el.setAttribute('src', defaultAvatar)
+  } else if (modifiers.background) {
+    el.setAttribute('src', defaultBackground)
+  } else {
+    el.remove() // 什么都不加 v-default-img 时 移除图片
+  }
+}
diff --git a/src/layout/index.vue b/src/layout/index.vue
index 53af195..cfffd88 100644
--- a/src/layout/index.vue
+++ b/src/layout/index.vue
@@ -1,6 +1,6 @@
 <template>
   <div class="app-wrapper">
-    <sidebar />
+    <sidebar/>
     <!-- ↑ 侧边菜单栏 ↑  -->
     <div
       class="mask-zIndex99"
@@ -10,25 +10,25 @@
     <!-- ↑ 移动端模式下展开侧边栏所出现的遮罩层 ↑  -->
     <div class="main-container">
       <header :class="{ 'fixed-header': fixedHeader }">
-        <nav-bar />
-        <tab-bar v-if="showTabBar" />
+        <nav-bar/>
+        <tab-bar v-if="showTabBar"/>
       </header>
-      <app-main />
+      <app-main/>
       <!-- ↑ 内容主体展示区域 ↑  -->
     </div>
-    <settings />
+    <settings/>
     <!-- ↑ 默认隐藏在右边的设置面板 ↑  -->
   </div>
 </template>
 
 <script setup>
 // <script setup>教程：https://v3.cn.vuejs.org/api/sfc-script-setup.html
-import { toRefs } from 'vue'
-import { throttle } from '/src/utils/util'
-import { useStyleStore } from '/src/store/style'
-import { useLayoutStore } from '/src/store/layout'
-import { batchSaveSetting } from '/src/utils/storage'
-import { AppMain, NavBar, Settings, Sidebar, TabBar } from './components'
+import {toRefs} from 'vue'
+import {throttle} from '/src/utils/util'
+import {useStyleStore} from '/src/store/style'
+import {useLayoutStore} from '/src/store/layout'
+import {batchSaveSetting} from '/src/utils/storage'
+import {AppMain, NavBar, Settings, Sidebar, TabBar} from './components'
 
 const styleStore = useStyleStore()
 const layoutStore = useLayoutStore()
diff --git a/src/store/layout.js b/src/store/layout.js
index cea98cb..6fa0a19 100644
--- a/src/store/layout.js
+++ b/src/store/layout.js
@@ -1,5 +1,6 @@
-import { defineStore } from 'pinia'
-import { getSetting } from '/src/utils/storage'
+import {defineStore} from 'pinia'
+import {getSetting} from '/src/utils/storage'
+// import variables from '/src/styles/vars.module.scss'
 
 const noRecordViewPath = ['/login']
 
diff --git a/src/styles/_variables.scss b/src/styles/_variables.scss
index 6c7ae14..f80a360 100644
--- a/src/styles/_variables.scss
+++ b/src/styles/_variables.scss
@@ -20,3 +20,10 @@ $scrollbar-width: 8px;
 $xl-width: 1920px; //  大大屏幕尺寸
 $lg-width: 1200px; // 大屏幕桌面尺寸
 $sm-width: 768px; // 小屏幕平板尺寸
+
+:export {
+  smWidth: $sm-width;
+  navbarHeight: $navbar-height;
+  tabBarHeight: $tabBar-height;
+  sidebarLogoHeight: $sidebar-logo-height;
+}
\ No newline at end of file
diff --git a/src/styles/vars.module.scss b/src/styles/vars.module.scss
new file mode 100644
index 0000000..4e37a3a
--- /dev/null
+++ b/src/styles/vars.module.scss
@@ -0,0 +1,11 @@
+$sidebar-logo-height: 42px;
+$navbar-height: 42px;
+$tabBar-height: 30px;
+$sm-width: 768px;
+
+:export {
+  smWidth: $sm-width;
+  navbarHeight: $navbar-height;
+  tabBarHeight: $tabBar-height;
+  sidebarLogoHeight: $sidebar-logo-height;
+}
\ No newline at end of file
diff --git a/vite.config.js b/vite.config.js
index 42cd11a..917bfa2 100644
--- a/vite.config.js
+++ b/vite.config.js
@@ -68,9 +68,7 @@ export default ({command}) => {
     css: {
       preprocessorOptions: {
         scss: {
-          additionalData: `
-            @import "/src/styles/_variables";
-          `,
+          additionalData: `@import "/src/styles/_variables";\n`,
         },
       },