JSFiddle - React, Tailwind, and code Playground

by brigand

HTML

<div id="thing"></div>

CSS

.hidden {
  display: none;
}

#thing {
  width: 2em;
  height: 2em;
  background: #999;
}

JavaScript

const thing = document.querySelector('#thing')
setInterval(() => {
	thing.classList.toggle('hidden')
})