JSFiddle - React, Tailwind, and code Playground

HTML

<div class="c1">
        <div class="c2"></div>        
    </div>

CSS

div {
            margin: 1em;
            border-style: solid;
        }

        .c1 {
            height: 100px;
            width: 200px;
            border-color: red;
        }

        .c2 {
            height: 10px;
            width: 10px;            
        }