当我们向上滚动时，两个div缩小，另一个div gowing

<div class="div1"></div>
<div class="div2"></div>
<div class="div3"></div>

.div1 {
  transform: scale(0.5);
  transition: transform 0.5s ease;
}

.div2 {
  transform: scale(0.5);
  transition: transform 0.5s ease;
}

.div3 {
  transform: scale(1.5);
  transition: transform 0.5s ease;
}

window.addEventListener('scroll', function() {
  var scrollDirection = getScrollDirection();
  
  if (scrollDirection === 'up') {
    document.querySelector('.div1').style.transform = 'scale(0.5)';
    document.querySelector('.div2').style.transform = 'scale(0.5)';
    document.querySelector('.div3').style.transform = 'scale(1.5)';
  } else if (scrollDirection === 'down') {
    document.querySelector('.div1').style.transform = 'scale(1)';
    document.querySelector('.div2').style.transform = 'scale(1)';
    document.querySelector('.div3').style.transform = 'scale(1)';
  }
});

function getScrollDirection() {
  var lastScrollTop = window.pageYOffset || document.documentElement.scrollTop;
  
  window.addEventListener('scroll', function() {
    var scrollTop = window.pageYOffset || document.documentElement.scrollTop;
    
    if (scrollTop > lastScrollTop) {
      lastScrollTop = scrollTop;
      return 'down';
    } else if (scrollTop < lastScrollTop) {
      lastScrollTop = scrollTop;
      return 'up';
    }
  });
}