/**
 * CSS cho Lazy Loading tối ưu
 */

/* Placeholder cho ảnh đang load */
img[data-src],
img[data-original] {
  opacity: 0;
  transition: opacity 0.3s ease-in-out;
  background-color: #f0f0f0;
  background-image: linear-gradient(90deg, #f0f0f0 0%, #e0e0e0 50%, #f0f0f0 100%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

/* Ảnh đã load xong */
img.lazy-loaded {
  opacity: 1;
}

/* Ảnh đang load */
img.lazy-loading {
  opacity: 0.5;
}

/* Ảnh lỗi */
img.lazy-error {
  opacity: 0.3;
  background-color: #f0f0f0;
}

/* Background images */
[data-bg],
[data-background] {
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  transition: opacity 0.3s ease-in-out;
}

[data-bg].lazy-bg-loaded,
[data-background].lazy-bg-loaded {
  opacity: 1;
}

/* Shimmer effect animation */
@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

/* Fade in effect */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

img.lazy-loaded {
  animation: fadeIn 0.3s ease-in-out;
}

/* Tối ưu cho mobile */
@media (max-width: 768px) {
  img[data-src],
  img[data-original] {
    min-height: 150px;
  }
}

/* Blur effect khi load (optional) */
img.lazy-loading {
  filter: blur(5px);
}

img.lazy-loaded {
  filter: blur(0);
  transition: filter 0.3s;
}