JSFiddle - React, Tailwind, and code Playground

HTML

<div style="background: #aaa;"></div>

CSS

div{
    width: 200px;
    height: 200px;
}

JavaScript

var elem = document.querySelector('div');

elem.style.setProperty('background', '#faa', 'important');
elem.style.removeProperty('background'); // doesn't work

elem.style.setProperty('background', '#afa');