Triggers classes on html elements based on the scroll position. It makes use of requestAnimationFrame so it doesn't jack the users scroll, that way the user / browser keeps their original scroll behaviour. Animations run when the browser is ready for it.

It's quite simple, just add the ScrollTrigger.min.js file to your HTML page. Then call ScrollTrigger.init() when the page has loaded. Like so:

<script src="ScrollTrigger.min.js"></script>
<script>
document.addEventListener('DOMContentLoaded',