JSFiddle - React, Tailwind, and code Playground

HTML

<div id="oval"></div>

CSS

#oval {
	width: 200px;
	height: 100px;
	background: red;
	-moz-border-radius: 100px / 50px;
	-webkit-border-radius: 100px / 50px;
	border-radius: 100px / 50px;
}