修改导航栏，添加标语“涉密不上网、上网不涉密”

src/views/main-navbar.vue

@@ -13,13 +13,13 @@
         <el-menu-item class="site-navbar__switch" index="0" @click="sidebarFold = !sidebarFold">
           <icon-svg name="zhedie"></icon-svg>
         </el-menu-item>
+        <el-menu-item style="text-align: center">
+          <b style="color: #ff0311;font-size: 24px">涉密不上网、上网不涉密</b>
+        </el-menu-item>
       </el-menu>
       <el-menu
         class="site-navbar__menu site-navbar__menu--right"
         mode="horizontal">
-        <el-menu-item style="text-align: center">
-          <span style="color: #ff0311;font-size: 18px;margin-top: 5px">涉密不上网、上网不涉密</span>
-        </el-menu-item>
         <el-menu-item index="0" @click="$router.push({ name: 'msgCenter' })">
           <template slot="title">
             <el-badge :value="cnt" :hidden="cnt < 1">