Part 2 - Adding scrollTop values to this.from and this.to

Post.js

onExit = () => {
  // we don't want to run this if there is no
  // preview element to transition to.
  if (!this.preview) return;

  this.from = {
    top: 0,
    height: this.post.offsetHeight,
    width: this.post.offsetWidth,
    borderRadius: this.postStyler.get('borderRadius'),
    scrollTop: windowScroll.get('top') // add this
  };
  
  // change this
  this.to = {
    ...this.getPreviewStyleAndPosition(),
    scrollTop: 0
  };

  const scrollTop = windowScroll.get('top');
  this.post.classList.add('scroll-block');
  this.postScroll.set('top', scrollTop);
};