fix: style problem in mobile; 🐛 #108

修复：移动端样式问题；

src/layouts/AdminLayout.vue

@@ -4,7 +4,7 @@
       <side-menu :theme="theme.mode" :menuData="menuData" :collapsed="false" :collapsible="false" @menuSelect="onMenuSelect"/>
     </drawer>
     <side-menu :class="[fixedSideBar ? 'fixed-side' : '']" :theme="theme.mode" v-else-if="layout === 'side'" :menuData="menuData" :collapsed="collapsed" :collapsible="true" />
-    <div v-if="fixedSideBar" :style="`width: ${sideMenuWidth}; min-width: ${sideMenuWidth};max-width: ${sideMenuWidth};`" class="virtual-side"></div>
+    <div v-if="fixedSideBar && !isMobile" :style="`width: ${sideMenuWidth}; min-width: ${sideMenuWidth};max-width: ${sideMenuWidth};`" class="virtual-side"></div>
     <drawer v-if="!hideSetting" v-model="showSetting" placement="right">
       <div class="setting" slot="handler">
         <a-icon :type="showSetting ? 'close' : 'setting'"/>