elementui部分内置类名不起效

Question

在vue-cli3项目中正确导入element-plus组件，复制官网组件代码时却发现"md-4"类名不起效

<template>
  <el-row class="mb-4">
    <el-button>Default</el-button>
    <el-button type="primary">Primary</el-button>
    <el-button type="success">Success</el-button>
    <el-button type="info">Info</el-button>
    <el-button type="warning">Warning</el-button>
    <el-button type="danger">Danger</el-button>
    <el-button>中文</el-button>
  </el-row>
  <el-row class="mb-4">
    <el-button plain>Plain</el-button>
    <el-button type="primary" plain>Primary</el-button>
    <el-button type="success" plain>Success</el-button>
    <el-button type="info" plain>Info</el-button>
    <el-button type="warning" plain>Warning</el-button>
    <el-button type="danger" plain>Danger</el-button>
  </el-row>
</template>

运行结果中mb-4(margin-bottom:4px)并没有生效

检查样式发现并没有这个类名

怀疑是组件的js没有配置好，没有生成该样式

这是官网中展示的效果，查看样式也确实由mb-4这个类名的样式

Answer 1

mb-4 你自己添加的类。你没写样式 当然没有效果