JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
	<div class="box-1"></div>
	<div class="box-2"></div>
</div>

CSS

.wrapper {
	display: flex;
}

.box-1 {
	flex: 1;
	width: 200px;
	height: 1000px;
	background-color: #2ABB9B;
}

.box-2 {
	flex: 1;
	width: 200px;
	height: 1000px;
	background-color: #16A085;
}