smooth_scrolling.js

/** 
 * Paste into Browser for smooth scrolling from top to bottom
 * @see https://css-tricks.com/smooth-scrolling-for-screencasts/
 */
const scrollElement = (element, scrollPosition, duration) => {
  
  // useful while testing to re-run it a bunch.
  // element.removeAttribute("style"); 
  
  const style = element.style;
  style.transition = duration + 's';
  style.transitionTimingFunction = 'ease-in-out';
  style.transform = 'translate3d(0, ' + -scrollPosition + 'px, 0)';
}

scrollElement(
  document.body, 
  (
    document.body.getBoundingClientRect().height
    -
    document.documentElement.clientHeight
    +
    25  // Stopping point
  ), 
  5     // seconds
);