JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo">
    Click me
    <div class="bar"></div>
</div>

CSS

#foo {
    height: auto;
    background: #333;
    color: white;
}

.bar {
    display: none;
    height: 200px;
    width: 30px;
    background: #f00;
}

JavaScript

$(function() {
    $("#foo").click(function() {  
        $(".bar").fadeToggle();
    });
});