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                html {
  --color1: transparent;
  --color2: transparent;
body {
  height: 400vh;
  background: linear-gradient(to bottom, var(--color1), var(--color2));


                // Using the smooth scroll library from Baptiste Briel

let scrollVal;
const smooth = new Smooth({
  // Smooth scroll settings
  native: true,
  section: document.body,
  ease: 0.2,
  // Make sure ScrollTrigger knows what value to use
  callback: val => {
    scrollVal = val;


// Use the same function for left and top since usually only one is used
function getSetPos(value) {
  if (arguments.length) { // setter
    smooth.vars.current = value; = value;
  return scrollVal; // getter

ScrollTrigger.scrollerProxy("body", {
  scrollTop: getSetPos,
  scrollLeft: getSetPos

// Regular ScrollTrigger stuff"html", {
  "--color1": "blue",
  "--color2": "green",
  scrollTrigger: {
    scrub: true