/* ===== 性能优化相关样式 ===== */

/* 懒加载指示器 */
.lazy-loading-indicator {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
    z-index: 100;
    backdrop-filter: blur(4px);
}

/* 小型加载动画 */
.loading-spinner-small {
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

/* 加载错误提示 */
.lazy-load-error {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(220, 53, 69, 0.9);
    color: white;
    padding: 12px;
    border-radius: 8px;
    font-size: 12px;
    text-align: center;
    z-index: 100;
    backdrop-filter: blur(4px);
}

.lazy-load-error button {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 11px;
    cursor: pointer;
    margin-top: 8px;
    transition: background-color 0.2s;
}

.lazy-load-error button:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* 页面加载指示器 */
.page-loading {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px 25px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 25px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    z-index: 1000;
    font-size: 14px;
    color: #667eea;
}

/* 没有更多内容 */
.no-more-content {
    text-align: center;
    padding: 40px 20px;
    color: #999;
    font-size: 14px;
    margin: 20px 0;
}

/* 加载更多错误 */
.load-more-error {
    text-align: center;
    padding: 20px;
    background: rgba(255, 245, 245, 0.8);
    border: 1px solid #ffcccb;
    border-radius: 10px;
    margin: 20px;
    color: #d63031;
}

.load-more-error button {
    margin-top: 10px;
    padding: 8px 16px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

/* 图片淡入动画 */
.fade-in {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.fade-in.loaded {
    opacity: 1;
}

/* 视频占位符 */
.video-placeholder {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    position: relative;
    overflow: hidden;
}

.video-placeholder::before {
    content: "🎬";
    font-size: 40px;
    opacity: 0.5;
}

/* 图片占位符 */
.image-placeholder {
    background: linear-gradient(45deg, #f0f0f0 25%, transparent 25%), 
                linear-gradient(-45deg, #f0f0f0 25%, transparent 25%), 
                linear-gradient(45deg, transparent 75%, #f0f0f0 75%), 
                linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    animation: slide 2s infinite linear;
}

@keyframes slide {
    0% { background-position: 0 0, 0 10px, 10px -10px, -10px 0px; }
    100% { background-position: 20px 20px, 20px 30px, 30px 10px, 10px 20px; }
}

/* 媒体项目悬停效果优化 */
.media-item {
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    will-change: transform;
}

.media-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

/* 视频控制优化 */
.media-item video {
    cursor: pointer;
    transition: opacity 0.2s ease;
}

.media-item video:hover {
    opacity: 0.9;
}

/* 骨架屏动画 */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* 响应式优化 */
@media (max-width: 768px) {
    .lazy-loading-indicator,
    .lazy-load-error {
        font-size: 11px;
        padding: 8px 12px;
    }
    
    .loading-spinner-small {
        width: 14px;
        height: 14px;
    }
    
    .page-loading {
        bottom: 10px;
        padding: 12px 20px;
        font-size: 12px;
    }
    
    .media-item:hover {
        transform: none; /* 移动端禁用悬停变换 */
    }
}

/* 减弱动画（尊重用户偏好） */
@media (prefers-reduced-motion: reduce) {
    .lazy-loading-indicator,
    .lazy-load-error,
    .media-thumbnail img {
        transition: none;
        animation: none;
    }
    
    .loading-spinner-small {
        animation: none;
        border-top-color: transparent;
    }
    
    .image-placeholder {
        animation: none;
        background: #f0f0f0;
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    .lazy-loading-indicator {
        background: #000;
        border: 2px solid #fff;
    }
    
    .lazy-load-error {
        background: #000;
        border: 2px solid #ff0000;
    }
}

/* 打印样式优化 */
@media print {
    .lazy-loading-indicator,
    .lazy-load-error,
    .loading-spinner-small {
        display: none;
    }
    
    .media-thumbnail img {
        opacity: 1 !important;
    }
}

/* ===== 统一性能优化模块样式 ===== */

/* 图片容器优化 */
.media-thumbnail {
    position: relative;
    overflow: hidden;
}

.media-thumbnail img {
    transition: opacity 0.3s ease;
    will-change: opacity;
}

.media-thumbnail img[data-src] {
    opacity: 0;
}

.media-thumbnail img[data-loaded="true"] {
    opacity: 1;
}

/* 视频容器优化 */
.video-container {
    position: relative;
    background: #000;
}

.video-container video {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

/* 优化性能的通用类 */
.performance-optimized {
    contain: layout style paint;
    will-change: transform;
}

.no-js-fallback {
    display: none;
}

.no-js .no-js-fallback {
    display: block;
}

/* 动画优化 */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 深色主题支持 */
@media (prefers-color-scheme: dark) {
    .image-placeholder {
                 background: linear-gradient(45deg, #333 25%, transparent 25%), 
                     linear-gradient(-45deg, #333 25%, transparent 25%), 
                     linear-gradient(45deg, transparent 75%, #333 75%), 
                     linear-gradient(-45deg, transparent 75%, #333 75%);
     }
}