JSFiddle - React, Tailwind, and code Playground

HTML

<div class="entry">entry (click me!)</div>
<div id="content">content</div>

CSS

.col2 {
    background-color: red;
}

JavaScript

$(".entry").click(function() {
    $('#content').addClass("col2");
    setTimeout(function() {
        $('#content').after('<div class="box col2">test</div>');
        $('.box:last').hide().show(300);
    }, 500);
});