element-plus/docs/examples/border/border.vue

<template>
  <table class="demo-border">
    <tbody>
      <tr>
        <td class="text">Name</td>
        <td class="text">Thickness</td>
        <td class="line">Demo</td>
      </tr>
      <tr>
        <td class="text">Solid</td>
        <td class="text">1px</td>
        <td class="line">
          <div></div>
        </td>
      </tr>
      <tr>
        <td class="text">Dashed</td>
        <td class="text">2px</td>
        <td class="line">
          <div class="dashed"></div>
        </td>
      </tr>
    </tbody>
  </table>
</template>
<style scoped>
.demo-border .text {
  width: 15%;
}
.demo-border .line {
  width: 70%;
}
.demo-border .line div {
  width: 100%;
  height: 0;
  border-top: 1px solid var(--el-border-color-base);
}
.demo-border .line .dashed {
  border-top: 2px dashed var(--el-border-color-base);
}
</style>