JSFiddle - React, Tailwind, and code Playground

HTML

<div>1</div>

CSS

div {
    width: 100px;
    height: 100px;
    background: red;
    -webkit-transition: all 2s; /* For Safari 3.1 to 6.0 */
    transition: all 2s;
}

div:hover {
    width: 300px;
    background: green;
}