Over Flow Elements

(function (debug) { var w = debug.documentElement.offsetWidth, t = debug.createTreeWalker(debug.body, NodeFilter.SHOW_ELEMENT), b; 
while (t.nextNode()) { b = t.currentNode.getBoundingClientRect(); 
if (b.right > w || b.left < 0) { t.currentNode.style.setProperty('outline', '1px dotted red', 'important'); 
console.log(t.currentNode); } };
}(document));