JSFiddle - React, Tailwind, and code Playground

HTML

<div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
</div>

CSS

body > div {
	background: #aaa;
	display: flex;
	flex-wrap: wrap;
}
body > div > div {
	flex-grow: 1;
	width: 33%;
	height: 100px;
}
body > div > div:nth-child(even) {
	background: #23a;
}
body > div > div:nth-child(odd) {
	background: #49b;
}