如何在滚动时将内容置于标题下？

.title {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 50px;
  background-color: #fff;
  z-index: 9999;
}

.content {
  margin-top: 50px;
}

window.addEventListener('scroll', function() {
  var titleHeight = document.querySelector('.title').offsetHeight;
  var scrollTop = window.pageYOffset || document.documentElement.scrollTop;
  var contentElement = document.querySelector('.content');
  
  if (scrollTop >= titleHeight) {
    contentElement.style.position = 'fixed';
    contentElement.style.top = titleHeight + 'px';
  } else {
    contentElement.style.position = 'static';
    contentElement.style.top = 'auto';
  }
});