伪元素的z-index定位

Question

我似乎无法弄清楚如何让线条位于圆圈下面。 Z-index无法正常工作，我将div设置为非静态。我怎么能做到这一点？我们的想法是，与圆圈重叠的线条部分将位于圆圈后面。

div.step-line {
  margin: 0;
}

div.step-col {
  padding: 30px 0;
  text-align: center;
}

div.step-line div.step-title:before {
  right: 50%;
}

div.step-line div.step-number {
  font-size: 26px;
  border-radius: 50%!important;
  display: inline-block;
  margin: auto;
  padding: 9px;
  border: 3px solid #e5e5e5;
  position: relative;
  z-index: 5;
  height: 60px;
  width: 60px;
  /*text-align: center;*/
}

div.step-line div.step-title {
  position:relative;
  font-size: 20px;
  font-weight: 400;
  text-transform: uppercase;
}

div.step-line div.step-title:after {
  content: '';
  height: 3px;
  width: 100%;
  position: absolute;
  background-color: #e5e5e5;
  z-index: 4;
  transform: translateY(-100%);
  top: -90%;
  left: 0%;
}

div.step-line div.step-col.first div.step-title:after {
  width: 50%;
  left: 50%;
}

div.step-line div.step-col.last div.step-title:after {
  width: 50%;
  right: 50%;
}

<div class="row step-line">
  <div class="col-md-4 step-col first">
    <div class="step-number">1</div>
    <div class="step-title">This is a step title</div>
    <div class="step-content">This is a description</div>
  </div>
  <div class="col-md-4 step-col">
    <div class="step-number">2</div>
    <div class="step-title">This is a step title</div>
    <div class="step-content">This is a description</div>
  </div>
  <div class="col-md-4 step-col last">
    <div class="step-number">3</div>
    <div class="step-title">This is a step title</div>
    <div class="step-content">This is a description</div>
  </div>
</div>

Answer 1

我从您的问题中了解到，您希望自己的线条位于这些圈子后面，只需在CSS中添加背景颜色background-color: white;

最终代码：

div.step-line div.step-number {
  font-size: 26px;
  border-radius: 50%!important;
  display: inline-block;
  margin: auto;
  padding: 9px;
  border: 3px solid #e5e5e5;
  position: relative;
  z-index: 5;
  height: 60px;
  width: 60px;
  /*text-align: center;*/
  background-color: white;
}