// From http://stackoverflow.com/questions/123999/how-to-tell-if-a-dom-element-is-visible-in-the-current-viewport function elementIsInView (el) { if (typeof jQuery === "function" && el instanceof jQuery) { el = el[0]; } const rect = el.getBoundingClientRect(); return ( rect.top >= 0 && rect.left >= 0 && rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) && rect.right <= (window.innerWidth || document.documentElement.clientWidth) ); } $(function() { // Change container tags