/* 懒加载基础样式 */
.lazy-loading {
    opacity: 0.5;
    transition: opacity 0.3s ease;
    background-color: #f5f5f5;
}

.lazy-loaded {
    opacity: 1;
    animation: fadeIn 0.5s ease;
}

.lazy-error {
    opacity: 1;
    background-color: #ffe6e6;
    position: relative;
}

/* 加载动画 */
@keyframes fadeIn {
    from { opacity: 0.5; }
    to { opacity: 1; }
}

/* 图片懒加载占位符 */
img.lazy-loading {
    min-height: 100px;
    min-width: 100px;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loadingShimmer 1.5s infinite;
}

/* 视频懒加载占位符 */
video.lazy-loading {
    min-height: 200px;
    background-color: #000;
    display: flex;
    align-items: center;
    justify-content: center;
}

video.lazy-loading::before {
    content: '🎬';
    font-size: 24px;
    color: rgba(255, 255, 255, 0.5);
}

/* 背景图片懒加载占位符 */
[data-bg].lazy-loading {
    min-height: 200px;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loadingShimmer 1.5s infinite;
}

/* 加载动画 */
@keyframes loadingShimmer {
    0% { background-position: -200px 0; }
    100% { background-position: 200px 0; }
}