JSFiddle - React, Tailwind, and code Playground

HTML

<div class='block'>
    <div class='container'></div>
</div>

CSS

.block {
    display: block;
    height: 100px;
    width: 100px;
    background: black;
}

.container {
    display: block;
    width: 30px;
    height: 30px;
    background: red;
    margin: 50px;
}