JSFiddle - React, Tailwind, and code Playground

HTML

<div id="first">
    <div id="second">
        <div id="third"></div>
    </div>
</div>

CSS

div {position:absolute;top:1.5em; left:1.5em}
#first {width:200px; height:200px; background:green}
#second {width:150px; height:150px; background:blue}
#third {width:100px; height:100px; background:black}