图片版权双十二活动

// 使用懒加载技术优化图片加载
document.addEventListener("DOMContentLoaded", function() {
  let lazyImages = [].slice.call(document.querySelectorAll("img.lazy"));
  
  if ("IntersectionObserver" in window) {
    let lazyImageObserver = new IntersectionObserver(function(entries, observer) {
      entries.forEach(function(entry) {
        if (entry.isIntersecting) {
          let lazyImage = entry.target;
          lazyImage.src = lazyImage.dataset.src;
          lazyImage.classList.remove("lazy");
          lazyImageObserver.unobserve(lazyImage);
        }
      });
    });
    
    lazyImages.forEach(function(lazyImage) {
      lazyImageObserver.observe(lazyImage);
    });
  } else {
    // 回退方案：直接加载所有图片
    lazyImages.forEach(function(lazyImage) {
      lazyImage.src = lazyImage.dataset.src;
    });
  }
});