JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test"></div>

CSS

#test {
    background-color: #00d4aa;
    width: 100px;
    height: 20px;
}

JavaScript

var $test = document.getElementById("test");
setTimeout(function() {
    $test.style.width = "200px";
}, 1000);
setTimeout(function() {
    // Using jQuery instead of the following
    // "pure DOM" code wouldn't work.
    $test.style.width = null;
}, 2000);