import { animate, onScroll } from 'animejs';

animate('.square', {
  x: '15rem',
  rotate: '1turn',
  duration: 2000,
  alternate: true,
  loop: true,
  ease: 'inOutQuad',
  autoplay: onScroll({
    container: '.scroll-container'
  })
});

<div class="scroll-container scroll-y">
  <div class="scroll-content grid square-grid">
    <div class="scroll-section padded">
      <div class="large centered row">
        <div class="label">scroll down</div>
      </div>
    </div>
    <div class="scroll-section padded">
      <div class="large row">
        <div class="square"></div>
      </div>
    </div>
  </div>
</div>