JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box"></div>

CSS

div {
  position: absolute;
 height: 50px;
 width: 50px;
  background: #900;
  top: 100px;
  left: 200px;
  will-change: transform;
  transform: translateZ(0);
}

JavaScript

document.getElementById("box").animate(
  [
    { transform: 'rotate(0) translate3D(-50%, -50%, 0)' },
    { transform: 'rotate(360deg) translate3D(-50%, -50%, 0)' }
  ], {
    duration: 500,
    iterations: Infinity
  }
);

function mySlowFunction(baseNumber) {
	console.time('mySlowFunction');
	var result = 0;	
	for (var i = Math.pow(baseNumber, 10); i >= 0; i--) {		
		result += Math.atan(i) * Math.tan(i);
	};
	console.timeEnd('mySlowFunction');
	return result;
}

setTimeout(() => mySlowFunction(5), 3000);