/**
 * Loading States and Skeleton Screens
 * Modern loading animations and placeholder content
 */

/* Loading Animations */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes shimmer {
    0% {
        background-position: -200px 0;
    }
    100% {
        background-position: calc(200px + 100%) 0;
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes spinner {
    to {
        transform: rotate(360deg);
    }
}

@keyframes bounceIn {
    0%, 20%, 53%, 80%, 100% {
        animation-timing-function: cubic-bezier(0.215, 0.61, 0.355, 1);
        transform: translate3d(0, 0, 0);
    }
    40%, 43% {
        animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
        transform: translate3d(0, -30px, 0);
    }
    70% {
        animation-timing-function: cubic-bezier(0.755, 0.05, 0.855, 0.06);
        transform: translate3d(0, -15px, 0);
    }
    90% {
        transform: translate3d(0, -4px, 0);
    }
}

/* Skeleton Loading Components */
.skeleton {
    background: linear-gradient(90deg, var(--gray-100) 25%, var(--gray-50) 50%, var(--gray-100) 75%);
    background-size: 200px 100%;
    animation: shimmer 2s infinite;
    border-radius: var(--radius-md);
    position: relative;
    overflow: hidden;
}

.skeleton::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.6), transparent);
    animation: shimmer 2s infinite;
}

/* Skeleton Variations */
.skeleton-text {
    height: 1rem;
    margin-bottom: 0.5rem;
    border-radius: var(--radius-sm);
}

.skeleton-text.large {
    height: 1.5rem;
}

.skeleton-text.small {
    height: 0.75rem;
}

.skeleton-title {
    height: 2rem;
    width: 60%;
    margin-bottom: 1rem;
    border-radius: var(--radius-md);
}

.skeleton-image {
    height: 200px;
    width: 100%;
    border-radius: var(--radius-lg);
    margin-bottom: 1rem;
}

.skeleton-avatar {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-full);
    margin-bottom: 1rem;
}

.skeleton-button {
    height: 3rem;
    width: 120px;
    border-radius: var(--radius-lg);
}

/* Card Skeleton */
.skeleton-card {
    padding: var(--space-lg);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    margin-bottom: var(--space-lg);
    background: var(--surface);
}

.skeleton-card .skeleton-image {
    height: 160px;
    margin: calc(-1 * var(--space-lg)) calc(-1 * var(--space-lg)) var(--space-lg);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
}

/* Loading States */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: all var(--duration-normal) var(--ease-out);
}

.loading-overlay.active {
    opacity: 1;
    visibility: visible;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-200);
    border-top: 3px solid var(--brand-primary);
    border-radius: var(--radius-full);
    animation: spinner 1s linear infinite;
}

.loading-dots {
    display: flex;
    gap: var(--space-xs);
    align-items: center;
}

.loading-dot {
    width: 8px;
    height: 8px;
    background: var(--brand-primary);
    border-radius: var(--radius-full);
    animation: pulse 1.4s ease-in-out infinite both;
}

.loading-dot:nth-child(1) { animation-delay: -0.32s; }
.loading-dot:nth-child(2) { animation-delay: -0.16s; }
.loading-dot:nth-child(3) { animation-delay: 0; }

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 4px;
    background: var(--gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
    position: relative;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
    border-radius: inherit;
    transition: width var(--duration-normal) var(--ease-out);
    position: relative;
}

.progress-bar-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

/* Button Loading States */
.btn-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}

.btn-loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid var(--surface);
    border-radius: var(--radius-full);
    animation: spinner 1s linear infinite;
}

/* Image Loading */
.image-loading {
    position: relative;
    background: var(--gray-100);
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 200px;
}

.image-loading::before {
    content: '';
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-200);
    border-top: 3px solid var(--brand-primary);
    border-radius: var(--radius-full);
    animation: spinner 1s linear infinite;
}

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

/* Form Loading States */
.form-loading {
    position: relative;
    pointer-events: none;
}

.form-loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.8);
    border-radius: inherit;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Section Loading */
.section-loading {
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: var(--space-lg);
}

.section-loading .loading-spinner {
    margin-bottom: var(--space-md);
}

.section-loading .loading-text {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    text-align: center;
}

/* Notification Loading */
.notification {
    position: fixed;
    top: var(--space-xl);
    right: var(--space-xl);
    background: var(--surface);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    box-shadow: var(--shadow-xl);
    z-index: 10000;
    transform: translateX(400px);
    transition: transform var(--duration-normal) var(--ease-out);
    display: flex;
    align-items: center;
    gap: var(--space-md);
    max-width: 400px;
}

.notification.show {
    transform: translateX(0);
}

.notification-success {
    border-left: 4px solid var(--brand-secondary);
}

.notification-error {
    border-left: 4px solid #dc3545;
}

.notification-info {
    border-left: 4px solid var(--brand-primary);
}

.notification-warning {
    border-left: 4px solid #ffc107;
}

.notification i {
    font-size: var(--text-lg);
}

.notification-success i {
    color: var(--brand-secondary);
}

.notification-error i {
    color: #dc3545;
}

.notification-info i {
    color: var(--brand-primary);
}

.notification-warning i {
    color: #ffc107;
}

/* Content Loading Placeholders */
.content-placeholder {
    padding: var(--space-2xl);
}

.content-placeholder .skeleton-title {
    width: 80%;
    margin: 0 auto var(--space-lg);
}

.content-placeholder .skeleton-text:nth-child(2) { width: 100%; }
.content-placeholder .skeleton-text:nth-child(3) { width: 85%; }
.content-placeholder .skeleton-text:nth-child(4) { width: 90%; }
.content-placeholder .skeleton-text:nth-child(5) { width: 75%; }

/* Gallery Loading */
.gallery-loading {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-xl);
    margin-top: var(--space-3xl);
}

.gallery-loading .skeleton-card .skeleton-image {
    height: 200px;
}

/* Testimonial Loading */
.testimonial-loading {
    display: flex;
    gap: var(--space-xl);
    overflow: hidden;
    padding: var(--space-xl) 0;
}

.testimonial-skeleton {
    min-width: 350px;
    padding: var(--space-lg);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    display: flex;
    gap: var(--space-md);
}

.testimonial-skeleton .skeleton-avatar {
    width: 40px;
    height: 40px;
    flex-shrink: 0;
}

.testimonial-skeleton .skeleton-content {
    flex: 1;
}

.testimonial-skeleton .skeleton-text:first-child {
    width: 60%;
    margin-bottom: var(--space-sm);
}

/* Page Transition Loading */
.page-loading {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    z-index: 10001;
    background: var(--gray-200);
}

.page-loading-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--brand-primary), var(--brand-accent));
    width: 0;
    transition: width var(--duration-normal) var(--ease-out);
    position: relative;
}

.page-loading-bar::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    width: 50px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.8));
    animation: shimmer 1s infinite;
}

/* Error States */
.error-state {
    text-align: center;
    padding: var(--space-4xl);
    color: var(--text-secondary);
}

.error-state i {
    font-size: var(--text-6xl);
    color: var(--gray-300);
    margin-bottom: var(--space-lg);
}

.error-state h3 {
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.error-state p {
    max-width: 400px;
    margin: 0 auto var(--space-lg);
}

.retry-button {
    background: var(--brand-primary);
    color: var(--surface);
    border: none;
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-lg);
    font-variation-settings: 'wght' var(--font-medium);
    cursor: pointer;
    transition: all var(--duration-normal) var(--ease-out);
}

.retry-button:hover {
    background: var(--brand-primary-dark);
    transform: translateY(-1px);
}

/* Mobile Loading Optimizations */
@media (max-width: 768px) {
    .notification {
        top: var(--space-lg);
        right: var(--space-lg);
        left: var(--space-lg);
        max-width: none;
        transform: translateY(-100px);
    }
    
    .notification.show {
        transform: translateY(0);
    }
    
    .skeleton-card {
        padding: var(--space-md);
    }
    
    .testimonial-skeleton {
        min-width: 280px;
        padding: var(--space-md);
    }
    
    .loading-overlay .loading-spinner {
        width: 32px;
        height: 32px;
        border-width: 2px;
    }
}

/* Accessibility for Loading States */
@media (prefers-reduced-motion: reduce) {
    .skeleton,
    .skeleton::after,
    .loading-spinner,
    .loading-dot,
    .progress-bar-fill::after,
    .btn-loading::after,
    .image-loading::before {
        animation: none;
    }
    
    .skeleton {
        background: var(--gray-100);
    }
    
    .loading-spinner {
        border-top-color: var(--brand-primary);
        border-right-color: var(--brand-primary);
    }
}

/* Dark Mode Loading States */
@media (prefers-color-scheme: dark) {
    .skeleton {
        background: linear-gradient(90deg, var(--gray-700) 25%, var(--gray-600) 50%, var(--gray-700) 75%);
    }
    
    .loading-overlay {
        background: rgba(15, 23, 42, 0.9);
    }
    
    .notification {
        background: var(--surface);
        border-color: var(--gray-600);
    }
    
    .error-state i {
        color: var(--gray-600);
    }
}

/* High Performance Loading */
.will-change-transform { will-change: transform; }
.will-change-opacity { will-change: opacity; }
.will-change-auto { will-change: auto; }

/* Loading state for images with WebP support */
.image-container {
    position: relative;
    overflow: hidden;
}

.image-container img {
    transition: opacity 0.3s ease;
    opacity: 1 !important;
}

.image-container img.loaded {
    opacity: 1 !important;
}

.image-container .image-placeholder {
    display: none !important;
}

.image-container .image-placeholder::before {
    content: '';
    width: 24px;
    height: 24px;
    border: 2px solid var(--gray-300);
    border-top: 2px solid var(--brand-primary);
    border-radius: 50%;
    animation: spinner 1s linear infinite;
}