纯css实现tab导航栏下划线

<div class="title">
      <span>基础信息</span>
</div>

 .title {
    position: relative;
    height: 40px;
    line-height: 40px;
    &::after {
      content: "";
      position: absolute;
      left: 0;
      bottom: 0;
      width: 100%;
      height: 2px;
      background-color: #f2f4fe;
    }
 
    span {
      display: inline-block;
      position: relative;
      padding: 0px 5px;
      font-size: 18px;
      color: #3d3d3d;
      &::after {
        content: "";
        position: absolute;
        left: 0;
        bottom: 0;
        width: 100%;
        height: 2px;
        background-color: #409eff;
        z-index: 1;
      }
    }
  }