JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<div id="element">Content</div>

JavaScript

var curOpacity = 0; 
function doWork(step) {
    for(var j  = 0; j <100000000; j++) { }
    console.log("Completed step: " + step);
    $("#element").css('opacity', step * 0.1);  
    if(step < 10)
        setTimeout(function() { doWork(step + 1); });
}
doWork(0);