javascript - 已设置位置，但 z-index 无效

Question

我想创建一个步骤进度条，但我的 CSS 有问题。
我想让圆圈被线覆盖，但是不行。
演示如下:

HTML:

ol {
  display: table;
  table-layout: fixed;
  width: 100%;
  margin: 0;
  padding: 0;
  list-style: none;
}

li {
  position: relative;
  display: table-cell;
  text-align: center;
}

li:after {
  content: "";
  position: relative;
  z-index: 1000;
  display: block;
  width: 2em;
  height: 2em;
  margin: 0 auto;
  line-height: 2em;
  color: #fff;
  border: 0.2em #e1e1e1 solid;
  border-radius: 100%;
}

li:not(:last-child):before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  z-index: -1;
  display: block;
  width: 100%;
  height: 0.2em;
  background-color: #e1e1e1;
}

<ol>
  <li>
    Order received
  </li>
  <li>
    Order received
  </li>
  <li>
    Order received
  </li>
  <li>
    Order received
  </li>
  <li>
    Order received
  </li>
</ol>

codepen

Answer 1

如果我理解正确的话，你只需在 &:after 选择器上设置 background-color 而不是 color

&:after {
  background-color: #fff;
}