JSFiddle - React, Tailwind, and code Playground

HTML

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

CSS

#test1{
	width: 204px;
	height: 102px;
	background-color: #243470;
}

#test2{
	width: 204px;
	height: 102px;
	background-color: #017761;
    transition-duration: 0.7s
}

#test1:hover + #test2{
    width: 408px;
}