JSFiddle - React, Tailwind, and code Playground

HTML

<div id="red">
    <div id="green"></div>
</div>

CSS

div {
    width: 300px;
    height: 300px
}
#red {
    background: red;
    z-index: 10;
    position: relative;
}
#green {
    background: green;
    width: 290px;
    z-index: -10
}