JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <span></span>
</div>

CSS

div{
background:#ccc;
width:200px;
height:200px;
-webkit-border-radius:10px;
}

div:first-child{
display:block;
width:200px;
height:200px;
background:#222;
}