JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test1"></div>
<div class="test2"></div>

CSS

body {
	margin:0;
	background-color:gray;
	overflow-y:visible;
}
.test1 {
	width:100vw;
	height:100vh;
	background-color:blue;
}


.test2 {
	width:100vw;
	height:100vh;
	background-color:red;
}