Highlight Overflowing Elements

gistfile1.txt

let w = document.documentElement.offsetWidth;
let t = document.createTreeWalker(document.body, NodeFilter.SHOW_ELEMENT);
let 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);
  }
}