element后台显示布局，左侧选选择框超出划上显示滚动条，右侧不超出全屏显示超出可下滑，左侧不会跟着一起划过

代码:

<template>
  <div>
    <el-container>
        <el-aside width="230px">
            <div>
                 <!-- style="244px" -->
                <el-menu
                default-active="2"
                @open="handleOpen"
                @close="handleClose"
                background-color="#545c64"
                text-color="#fff"
                active-text-color="#ffd04b">
                    <el-submenu index="1">
                        <template slot="title">
                        <i class="el-icon-location"></i>
                        <span>导航一</span>
                        </template>
                        <el-menu-item-group>
                        <template slot="title">分组一</template>
                        <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">
                        <template slot="title">选项4</template>
                        <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-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>

        </el-aside>
        <el-container>
            <el-header>Header</el-header>
            <el-main>
                <div style="font-size:50px;">main</div>
                <div style="font-size:50px;">main</div>
                <div style="font-size:50px;">main</div>
                <div style="font-size:50px;">main</div>

            </el-main>
            <el-footer>Footer</el-footer>
        </el-container>
    </el-container>
  </div>
</template>

<script>
export default {
    methods: {
      handleOpen(key, keyPath) {
        console.log(key, keyPath);
      },
      handleClose(key, keyPath) {
        console.log(key, keyPath);
      }
    }
}
</script>


<style lang="stylus" scoped>
  .el-header, .el-footer {
    background-color: #B3C0D1;
    color: #333;
    text-align: center;
    line-height: 60px;
  }
  .el-menu{
     border-right:none 
  }
  .el-aside {
    background-color: #545c64;
    color: #333;
    text-align: center;
    line-height: 200px;
    height: 100vh;
    position:fixed;
    top:0;
    left:0;
    overflow-y:hidden;
    overflow-x:hidden;
  }
  .el-aside:hover{
      overflow-y:auto;
  }
    .el-aside::-webkit-scrollbar {/*滚动条整体样式*/
             6px;     /*高宽分别对应横竖滚动条的尺寸*/
            height: 1px;
        }
    .el-aside::-webkit-scrollbar-thumb {/*滚动条里面小方块*/
            border-radius: 10px;
            -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
            background: #B3C0D1;
        }
    .el-aside::-webkit-scrollbar-track {/*滚动条里面轨道*/
            -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
            border-radius: 10px;
            background: #D3DCE6;
        }
  .el-main {
    background-color: #E9EEF3;
    color: #333;
    text-align: center;
    line-height: 160px;
    min-height: calc(100vh - 120px);
  }
  body > .el-container {
    margin-bottom: 40px;
  }
  .el-container:nth-child(5) .el-aside,
  .el-container:nth-child(6) .el-aside {
    line-height: 260px;
  }
  .el-container:nth-child(7) .el-aside {
    line-height: 320px;
  }
</style>

效果：