JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box">
    Initial Content
    <div class="hidden">
        This is hidden content
    </div>
</div>

CSS

#box {
    height:auto;
    background:#000;
    color:#fff;
    cursor:pointer;
}
.hidden {
    height:200px;
    display:none;
}
    .hidden.open {
        display:block;
    }

JavaScript

$(document).ready(function() {
    $('#box').click(function() {
        $(this).find(".hidden").toggleClass('open');
    });
});