JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outsideLayer">
    <div id="insideLayer">I'm the inside layer.</div>
</div>

CSS

#outsideLayer {
    position: relative;
    width: 500px;
    height: 500px;
    background: green;
}
#insideLayer {
    position: absolute;
    top: 5px;
    right: 5px;
    width: 100px;
    height: 100px;
    background: red;
}