JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <div id="child">
    </div>
</div>

CSS

body,html{margin:0;background:yellow;}
#parent{
    width:300px;
    height:300px;
    background:aqua;
    
}
#child{
    margin: 100px;
    width:500px;
    height:500px;
    background:black;
    
}