/**
 * Advanced Skeleton Loading System with Progressive Loading
 * Version: 2.0.0
 * Features: GPU acceleration, LQIP support, adaptive animations
 */

/* Base skeleton styles with GPU acceleration */
.skeleton {
    background: linear-gradient(90deg, #ffffff 25%, #f8fafc 50%, #ffffff 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border: 1px solid #f1f5f9;
    border-radius: 8px;
    position: relative;
    overflow: hidden;
    will-change: background-position;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

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

    100% {
        background-position: -200% 0;
    }
}

/* Optimized shimmer animation with GPU acceleration */
@keyframes skeleton-shimmer-optimized {
    0% {
        transform: translate3d(-100%, 0, 0);
    }
    100% {
        transform: translate3d(100%, 0, 0);
    }
}

/* Image skeleton with GPU optimization */
.skeleton-image {
    width: 100%;
    height: 200px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 8px;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-image::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

@keyframes skeleton-shimmer {
    0% {
        left: -100%;
    }

    100% {
        left: 100%;
    }
}

/* Product card skeleton with containment */
.skeleton-product-card {
    padding: 16px;
    border: 1px solid #f1f5f9;
    border-radius: 12px;
    background: #ffffff;
    contain: layout style;
    isolation: isolate;
}

.skeleton-product-image {
    width: 100%;
    aspect-ratio: 1;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 8px;
    margin-bottom: 12px;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-product-image::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

/* Text skeleton lines with GPU optimization */
.skeleton-text {
    height: 16px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 4px;
    margin-bottom: 8px;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-text::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

.skeleton-text.short {
    width: 60%;
}

.skeleton-text.medium {
    width: 80%;
}

.skeleton-text.long {
    width: 100%;
}

/* Title skeleton with GPU optimization */
.skeleton-title {
    height: 20px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 4px;
    margin-bottom: 12px;
    width: 75%;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-title::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

/* Price skeleton with GPU optimization */
.skeleton-price {
    height: 18px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 4px;
    width: 40%;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-price::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

/* Gallery skeleton with containment */
.skeleton-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    padding: 20px;
    contain: layout style;
    isolation: isolate;
}

/* Hero image skeleton with GPU optimization */
.skeleton-hero {
    width: 100%;
    height: 400px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 12px;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.8s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

/* Avatar skeleton with GPU optimization */
.skeleton-avatar {
    width: 40px;
    height: 40px;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 50%;
    position: relative;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

.skeleton-avatar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.2s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
}

/* Loading state for actual images with GPU optimization */
.image-loading {
    position: relative;
    background: #ffffff;
    border: 1px solid #f1f5f9;
    border-radius: 8px;
    overflow: hidden;
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    contain: layout style paint;
}

/* Override for color palette loading */
.image-loading.color-palette {
    background: transparent;
    border: none;
}

/* Progressive loading state */
.progressive-loading {
    position: relative;
    background: transparent;
    border: none;
    overflow: hidden;
}

.progressive-loading img {
    transition: filter 0.5s ease, transform 0.5s ease;
}

/* Progressive loading blur effect */
.progressive-loading img[style*="blur"] {
    filter: blur(5px);
    transform: scale(1.05);
    will-change: filter, transform;
}

/* High-quality image loaded state */
.progressive-loading img:not([style*="blur"]) {
    filter: none;
    transform: scale(1);
}

/* LQIP (Low-Quality Image Placeholder) support */
img.lqip-active {
    filter: blur(10px);
    transform: scale(1.05);
    transition: filter 0.5s ease, transform 0.5s ease;
    will-change: filter, transform;
}

img.lqip-active.image-loaded {
    filter: none;
    transform: scale(1);
}

.image-loading::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            transparent,
            rgba(241, 245, 249, 0.8),
            transparent);
    animation: skeleton-shimmer-optimized 1.5s infinite;
    will-change: transform;
    transform: translate3d(-100%, 0, 0);
    backface-visibility: hidden;
    z-index: 1;
}

.image-loading img {
    opacity: 0;
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
    transform: scale(0.95);
    will-change: opacity, transform;
}

.image-loaded::before {
    display: none;
}

.image-loaded img {
    opacity: 1;
    transform: scale(1);
}

/* Fade-in animation variants */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.image-loaded.fade-in-up img {
    animation: fadeInUp 0.6s ease-out forwards;
}

/* Error state with retry button */
.image-error {
    background: #fee2e2;
    border: 1px solid #fecaca;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100px;
    color: #dc2626;
    position: relative;
    padding: 20px;
}

.image-error img {
    display: none;
}

.image-error::after {
    content: '⚠️ Image failed to load';
    font-size: 14px;
    text-align: center;
}

.image-error-message {
    font-size: 14px;
    text-align: center;
    padding: 20px;
}

/* Priority loading indicator */
img[data-priority="high"] {
    content-visibility: auto;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {

    .skeleton,
    .skeleton-image,
    .skeleton-product-image,
    .skeleton-text,
    .skeleton-title,
    .skeleton-price,
    .skeleton-hero,
    .skeleton-avatar,
    .image-loading {
        background: #D3D3D3;
    }

    .skeleton::before,
    .skeleton-image::before,
    .skeleton-product-image::before,
    .skeleton-text::before,
    .skeleton-title::before,
    .skeleton-price::before,
    .skeleton-hero::before,
    .skeleton-avatar::before,
    .image-loading::before {
        background: linear-gradient(90deg,
                transparent,
                rgba(255, 255, 255, 0.3),
                transparent);
    }

    .skeleton-product-card {
        background: #FFFFFF;
        border-color: #FFFFFF;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {

    .skeleton,
    .skeleton::before,
    .skeleton-image::before,
    .skeleton-product-image::before,
    .skeleton-text::before,
    .skeleton-title::before,
    .skeleton-price::before,
    .skeleton-hero::before,
    .skeleton-avatar::before,
    .image-loading::before {
        animation: none;
    }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .skeleton-gallery {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 15px;
        padding: 15px;
    }

    .skeleton-hero {
        height: 250px;
    }

    .skeleton-product-image {
        aspect-ratio: 1.2;
    }
    
    /* Reduce animation on mobile for better performance */
    .skeleton::before,
    .skeleton-image::before,
    .skeleton-product-image::before,
    .skeleton-text::before,
    .skeleton-title::before,
    .skeleton-price::before,
    .skeleton-hero::before,
    .skeleton-avatar::before,
    .image-loading::before {
        animation-duration: 2s;
    }
}

/* High-performance mode for slow connections */
@media (prefers-reduced-data: reduce) {
    .skeleton::before,
    .skeleton-image::before,
    .skeleton-product-image::before,
    .skeleton-text::before,
    .skeleton-title::before,
    .skeleton-price::before,
    .skeleton-hero::before,
    .skeleton-avatar::before,
    .image-loading::before {
        animation: none;
        background: #f1f5f9;
    }
}

/* Content visibility optimization */
.skeleton-gallery,
.skeleton-product-card {
    content-visibility: auto;
    contain-intrinsic-size: 300px;
}

/* Color Palette-based LQIP System */
.color-palette-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f0f0f0 0%, #e0e0e0 100%);
    border-radius: 8px;
    overflow: hidden;
    z-index: 1; /* Lower z-index so image can appear on top */
    transition: opacity 0.6s ease-out;
    pointer-events: none; /* Prevent interaction */
}

/* Color palette gradient variations */
.color-palette-gradient-1 {
    background: linear-gradient(135deg, var(--color-1) 0%, var(--color-2) 100%);
}

.color-palette-gradient-2 {
    background: linear-gradient(45deg, var(--color-1) 0%, var(--color-2) 50%, var(--color-3) 100%);
}

.color-palette-gradient-3 {
    background: radial-gradient(circle at 30% 30%, var(--color-1) 0%, var(--color-2) 70%, var(--color-3) 100%);
}

.color-palette-gradient-4 {
    background: conic-gradient(from 180deg at 50% 50%, var(--color-1), var(--color-2), var(--color-3), var(--color-1));
}

/* Animated color palette placeholders */
.color-palette-animated {
    background-size: 200% 200%;
    animation: colorPaletteShift 8s ease infinite;
}

@keyframes colorPaletteShift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* Subtle shimmer effect on color palette */
.color-palette-shimmer::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: colorShimmer 2s infinite;
    z-index: 15; /* Higher than placeholder but still allows colors to show */
}

@keyframes colorShimmer {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

/* Image wrapper with color palette support */
.image-loading.color-palette {
    background: transparent;
    border: none;
    display: block;
    position: relative;
    min-height: 200px; /* Minimum height to prevent collapse */
}

.image-loading.color-palette .color-palette-placeholder {
    opacity: 1;
    display: block; /* Ensure it's displayed */
}

.image-loaded.color-palette .color-palette-placeholder {
    opacity: 0;
    pointer-events: none;
    visibility: hidden; /* Ensure it's completely hidden */
}

/* Ensure color palette placeholder is visible over default loading background */
.image-loading.color-palette::before {
    display: none; /* Hide the default shimmer when using color palette */
}

/* Fallback for browsers without CSS custom properties support */
.no-cssvars .color-palette-placeholder {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
}

/* Dark mode support for color palette */
@media (prefers-color-scheme: dark) {
    .color-palette-placeholder {
        opacity: 0.9;
    }
    
    .color-palette-shimmer::before {
        background: linear-gradient(
            90deg,
            transparent,
            rgba(255, 255, 255, 0.1),
            transparent
        );
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .color-palette-animated {
        animation: none;
    }
    
    .color-palette-shimmer::before {
        animation: none;
    }
}

/* Performance optimizations */
.color-palette-placeholder {
    will-change: opacity;
    contain: layout style paint;
    backface-visibility: hidden;
    transform: translateZ(0);
}

/* Smooth transition for image reveal */
.color-palette-reveal {
    position: relative;
    overflow: hidden;
    display: block;
    width: 100%;
    height: 100%;
}

.color-palette-reveal img {
    position: relative;
    z-index: 2; /* Ensure image is above placeholder */
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.color-palette-reveal.image-loaded img {
    opacity: 1;
}

/* Loading state with color palette */
.color-palette-loading {
    position: relative;
    background: var(--placeholder-bg, #f8f9fa);
}

.color-palette-loading::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--color-gradient, linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%));
    z-index: 1;
}

/* Error state with color palette */
.color-palette-error {
    background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100px;
    color: #dc2626;
    border-radius: 8px;
}

.color-palette-error::after {
    content: '⚠️ Image failed to load';
    font-size: 14px;
    text-align: center;
    padding: 20px;
}