JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test">This is a test</div>

CSS

#test {
    padding: 1em;
    font-size: 50px;
    font-weight: bold;
}

JavaScript

var elem = document.getElementById('test');

elem.style.setProperty('color', 'green', 'important');
elem.style.color = 'red';