JSFiddle - React, Tailwind, and code Playground

by Softlink

HTML

<div class="block b1"></div>
<div class="block b2"></div>
<div class="block b3"></div>

CSS

.block{
    position: relative;
    width: 200px;
    height: 200px;
    margin: 50px;
    border: 1px solid #ccc;
}

.block:before{
    content:'';
    position: absolute;
    height: 100%;
    width: 2px;
    background: #222;
}

.b1:before{
    left: -10px;
}

.b2:before{
    right: -10px;
}