element的menu折叠隐藏效果

<template>
 <div class="main">
  <div class="left_main" :class="{ left_main_show: openStatus }">
   <el-menu
    id="elmenu"
    background-color="#545c64"
    text-color="#fff"
    active-text-color="#ffd04b"
    class="el-menu-vertical-demo"
    :collapse="openStatus"
   >
    <el-submenu index="1">
     <template slot="title">
      <i class="el-icon-location"></i>
      <span slot="title">导航一</span>
     </template>
     <el-menu-item-group>
      <span slot="title">分组一</span>
      <el-menu-item index="1-1">选项1</el-menu-item>
      <el-menu-item index="1-2">选项2</el-menu-item>
     </el-menu-item-group>
     <el-menu-item-group title="分组2">
      <el-menu-item index="1-3">选项3</el-menu-item>
     </el-menu-item-group>
     <el-submenu index="1-4">
      <span slot="title">选项4</span>
      <el-menu-item index="1-4-1">选项1</el-menu-item>
     </el-submenu>
    </el-submenu>
    <el-menu-item index="2">
     <i class="el-icon-menu"></i>
     <span slot="title">导航二</span>
    </el-menu-item>
    <el-menu-item index="3" disabled>
     <i class="el-icon-document"></i>
     <span slot="title">导航三</span>
    </el-menu-item>
    <el-menu-item index="4">
     <i class="el-icon-setting"></i>
     <span slot="title">导航四</span>
    </el-menu-item>
   </el-menu>
  </div>
  <div class="right_main">
   <div class="open_close">
    <i @click="change" v-if="open_close" class="el-icon-s-fold"></i>
    <i @click="change" v-else class="el-icon-s-unfold"></i>
   </div>
  </div>
 </div>
</template>
<script>
export default {
 name: 'Always',
 data() {
  return {
   openStatus: false,
   open_close: true,
  }
 },
 methods: {
  change() {
   this.openStatus = !this.openStatus
   if (this.openStatus) {
    setTimeout(() => {
     this.open_close = false
    }, 1000)
   } else {
    setTimeout(() => {
     this.open_close = true
    }, 1000)
   }
  },
 },
}
</script>
<style lang="scss" scoped>
.main {
 display: flex;
 width: 100%;
 height: 100vh;
 .left_main {
  width: 180px;
  text-align: center;
  transition: width 1s;
  background-color: #545c64;
  .el-menu {
   border: none;
   height: 100%;
   text-align: left;
  }
  //  关键，必须加上，否则在折叠时会出现第一个文字卡顿后消失
  .el-menu:not(.el-menu--collapse) {
   width: 100%;
  }
 }

 .right_main {
  flex: 1;
  background-color: brown;
  position: relative;
  .open_close {
   position: absolute;
   left: 0;
   top: 0;
   color: white;
   font-size: 24px;
  }
 }
 .left_main_show {
  width: 60px;
 }
}
</style>