hr标签如何做成这种效果？

Answer 1

<hr class="hr">

.hr{

    position: relative;

}

.hr:after{

    content: "";

    position: absolute;

    top: 0;left: 0;right: 0;bottom: 0;

    margin: auto;

    display: block;

    border: 1px solid #ccc;

    height: 10px;

    width: 10px;

    background-color: #fff;

}