JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>
<section>Texte...</section>

CSS

html, body {margin: 0;height: 100%;}
body:before {content: "";display: block;height: 100%;}
div {position: absolute;top: 0;width: 100%;height: 100%;background: #c00;}
section {background: #09f;}