JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-git2.js"></script>
<button id="toggle">fadeToggle()</button>
<div id="test"></div>

CSS

#test {
    margin: 1.5em auto;
    width: 10em;
    height: 10em;
    background: black;
}

JavaScript

$('#toggle').click(function() {
    $('#test').fadeToggle('slow');
});