element 弹窗出现 会出现蓝框

<style>
  :focus{
    outline:none
  }
</style>
<div id="app">
<el-button @click="drawer = true" type="primary" style="margin-left: 16px;">
  点我打开
</el-button>

<el-drawer
  title="我是外面的 Drawer"
  :visible.sync="drawer"
  size="50%">
  <div>
   <el-button @click="innerDrawer = true">打开里面的!</el-button>
   <el-drawer
     title="我是里面的"
     :append-to-body="true"
     :visible.sync="innerDrawer">
     <p>_(:зゝ∠)_</p>
   </el-drawer>
  </div>
</el-drawer>
</div>

 //   一定不要用这个 scoped 因为有可能项目中不止这一个弹窗，要全局去掉
<style lang="scss" >         
   // 去掉弹窗出现时的出现蓝框
:focus {
  outline: 0;
}
</style>