/* Loading States and Lazy Loading Styles */

/* Lazy Loading Image States */
img[data-src], .lazy-bg[data-bg] {
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
    background-color: var(--bg-secondary);
}

img.loading, .lazy-bg.loading {
    opacity: 0.5;
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-hover) 50%, 
        var(--bg-secondary) 75%
    );
    background-size: 200% 100%;
    animation: loading-shimmer 1.5s infinite;
}

img.loaded, .lazy-bg.loaded {
    opacity: 1;
}

img.error, .lazy-bg.error {
    opacity: 0.7;
    background-color: var(--error-color);
    position: relative;
}

img.error::after {
    content: '⚠️';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 2rem;
    color: var(--text-secondary);
}

/* Loading Shimmer Animation */
@keyframes loading-shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

/* Loading Overlay */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(var(--bg-primary-rgb), 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(2px);
}

.loading-spinner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--bg-secondary);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-text {
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
}

/* Button Loading States */
.btn.loading {
    opacity: 0.7;
    cursor: not-allowed;
    position: relative;
}

.button-spinner {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top: 2px solid currentColor;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-right: 8px;
}

/* Spin Animation */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Content Loading Skeleton */
.content-skeleton {
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-hover) 50%, 
        var(--bg-secondary) 75%
    );
    background-size: 200% 100%;
    animation: loading-shimmer 1.5s infinite;
    border-radius: 8px;
}

.skeleton-text {
    height: 1em;
    margin: 0.5em 0;
}

.skeleton-title {
    height: 1.5em;
    width: 70%;
    margin: 1em 0;
}

.skeleton-paragraph {
    height: 1em;
    margin: 0.3em 0;
}

.skeleton-paragraph:nth-child(odd) {
    width: 95%;
}

.skeleton-paragraph:nth-child(even) {
    width: 80%;
}

.skeleton-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.skeleton-thumbnail {
    width: 100%;
    height: 200px;
    border-radius: 8px;
}

/* Video Grid Loading */
.video-grid.loading .video-card {
    opacity: 0.6;
}

.video-card.loading .video-thumbnail {
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-hover) 50%, 
        var(--bg-secondary) 75%
    );
    background-size: 200% 100%;
    animation: loading-shimmer 1.5s infinite;
}

/* Page Loading States */
.page-loading {
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.page-loading .loading-spinner {
    transform: scale(1.2);
}

/* Search Loading */
.search-loading {
    padding: 2rem;
    text-align: center;
}

/* Upload Progress */
.upload-progress {
    margin: 1rem 0;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--bg-secondary);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    border-radius: 4px;
    transition: width 0.3s ease;
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, 
        transparent 0%, 
        rgba(255, 255, 255, 0.3) 50%, 
        transparent 100%
    );
    animation: progress-shine 1.5s infinite;
}

@keyframes progress-shine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* Infinite Scroll Loading */
.infinite-scroll-loading {
    padding: 2rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

/* Form Loading States */
.form-loading input,
.form-loading textarea,
.form-loading select {
    opacity: 0.6;
    pointer-events: none;
}

/* Dark Mode Adjustments */
[data-theme="dark"] .loading-overlay {
    background: rgba(var(--bg-primary-rgb), 0.9);
}

[data-theme="dark"] .content-skeleton {
    background: linear-gradient(90deg, 
        var(--bg-secondary) 25%, 
        var(--bg-hover) 50%, 
        var(--bg-secondary) 75%
    );
}

/* Mobile Optimizations */
@media (max-width: 768px) {
    .loading-spinner {
        gap: 0.5rem;
    }
    
    .spinner {
        width: 32px;
        height: 32px;
        border-width: 3px;
    }
    
    .loading-text {
        font-size: 0.8rem;
    }
    
    .button-spinner {
        width: 14px;
        height: 14px;
        margin-right: 6px;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    .spinner,
    .button-spinner {
        animation: none;
    }
    
    .loading-shimmer,
    .content-skeleton {
        animation: none;
    }
    
    img[data-src], .lazy-bg[data-bg] {
        transition: none;
    }
}