JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box">Hello World</div>

CSS

#box {
    height:200px;
    width:200px;
    border:5px solid black;
    color:blue;
    background:rgba(0, 0, 0, 0);
    transition:background 200ms ease-in;
}
#box:hover {
    background:rgba(0, 0, 0, .5);
}