JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<div>Hi There</div>
<button>Fade In</button>

JavaScript

$("div").css({ opacity: 0.1 });
$("button").click(function() {
    $("div").animate({ opacity:1 }, 2000);
});