/**
 * 🎭 SKELETON & SHIMMER LOADING COMPONENTS
 * 
 * Unified skeleton loading states for all components
 * Mobile-friendly with 44px minimum touch targets
 * Using only CSS variables from variables.css
 */

/* ============================================================================
   💀 BASE SKELETON STYLES
   ============================================================================ */

.skeleton {
    position: relative;
    overflow: hidden;
    background: var(--border);
    border-radius: var(--radius-sm);
    animation: skeleton-pulse 1.5s ease-in-out infinite;
}

.skeleton::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent 25%,
        var(--border-light) 50%,
        transparent 75%
    );
    background-size: 200% 100%;
    animation: skeleton-shimmer 1.5s infinite;
}

/* ============================================================================
   📏 SKELETON LINE VARIANTS  
   ============================================================================ */

.skeleton-line {
    height: 16px;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

.skeleton-line-short {
    height: 14px;
    width: 60%;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
    margin-left: auto;
}

.skeleton-line-xs {
    height: 12px;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

.skeleton-line-lg {
    height: 20px;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

/* ============================================================================
   🎯 SKELETON BLOCKS FOR STATISTICS
   ============================================================================ */

.skeleton-stat-block {
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-shimmer 1.5s infinite;
    color: transparent;
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    border: 1px solid var(--border);
    min-height: var(--touch-target-min);
}

.skeleton-stat-number {
    height: 24px;
    width: 50%;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

.skeleton-stat-label {
    height: 14px;
    width: 80%;
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

/* ============================================================================
   🎭 SKELETON CARDS
   ============================================================================ */

.skeleton-card {
    padding: var(--spacing-md);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    min-height: var(--touch-target-min);
}

.skeleton-card .skeleton-line:first-child {
    margin-bottom: var(--spacing-xs);
}

.skeleton-card .skeleton-line:last-child {
    width: 70%;
}

/* ============================================================================
   📱 MOBILE OPTIMIZATIONS
   ============================================================================ */

@media (max-width: 768px) {
    .skeleton-stat-block {
        min-height: var(--touch-target-min);
        padding: var(--spacing-sm);
    }
    
    .skeleton-card {
        min-height: var(--touch-target-min);
        padding: var(--spacing-sm);
    }
}

/* ============================================================================
   ✨ ANIMATIONS
   ============================================================================ */

@keyframes skeleton-pulse {
    0%, 100% { 
        opacity: 1; 
    }
    50% { 
        opacity: 0.7; 
    }
}

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

/* ============================================================================
   🎯 COMPONENT-SPECIFIC SKELETON STATES
   ============================================================================ */

/* Quote card skeleton */
.quote-card.skeleton {
    cursor: default;
    animation: skeleton-pulse 1.5s ease-in-out infinite;
}

.quote-card.skeleton:hover {
    transform: none;
    box-shadow: none;
    border-color: var(--border);
}

.quote-card.skeleton .quote-text,
.quote-card.skeleton .quote-author {
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    color: transparent;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

/* Statistics grid skeleton */
.stats-grid.skeleton .stat-item {
    animation: skeleton-pulse 1.5s ease-in-out infinite;
    background: var(--border);
}

.stats-grid.skeleton .stat-value,
.stats-grid.skeleton .stat-label {
    background: linear-gradient(
        90deg, 
        var(--border) 25%, 
        var(--border-light) 50%, 
        var(--border) 75%
    );
    background-size: 200% 100%;
    color: transparent;
    border-radius: var(--radius-sm);
    animation: skeleton-shimmer 1.5s infinite;
}

/* ============================================================================
   🌟 LOADING STATE UTILITIES
   ============================================================================ */

.loading-overlay {
    position: relative;
}

.loading-overlay::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(1px);
    z-index: 1;
}

.fade-in {
    animation: fadeIn var(--duration-normal) var(--ease-out);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================================================
   🔧 ACCESSIBILITY & SCREEN READERS
   ============================================================================ */

.skeleton,
.skeleton-line,
.skeleton-line-short,
.skeleton-line-xs,
.skeleton-line-lg,
.skeleton-stat-block,
.skeleton-card {
    /* Indicate loading state to screen readers */
    aria-label: "Загрузка...";
}

.skeleton::before {
    /* Hide shimmer decoration from screen readers */
    speak: none;
}