/**
 * ICA Gallery Slider Styles
 * 
 * Optimized for performance with CSS Grid, scroll-snap,
 * and responsive design. Includes accessibility features.
 * 
 * @package Illinois_Conservatory
 * @since 1.0.0
 */

/* ==========================================================================
   Component Containment
   ========================================================================== */

/* Self-contained component - no need to affect body */
.ica-slider-section--gallery {
    contain: layout style;
}

/* ==========================================================================
   Main Slider Wrapper - CLS Prevention
   ========================================================================== */

.ica-slider-section--gallery {
    position: relative;
    width: 100%;
    max-width: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden; /* Prevent horizontal page scrolling */
    box-sizing: border-box;
    /* CLS Prevention: Reserve space for content */
    min-height: 50vh; /* Reserve minimum height to prevent layout shift */
    contain: layout style paint; /* Optimize rendering performance */
}

.ica-slider-wrapper {
    position: relative;
    contain: layout style paint; /* Optimize rendering performance */
    overflow: hidden;
    border-radius: 0;
    box-shadow: none;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    /* CLS Prevention: Reserve space */
    min-height: 50vh;
}

/* ==========================================================================
   Slider Track (Grid Layout)
   ========================================================================== */

.ica-slider-track {
    display: grid;
    grid-auto-flow: column;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    scrollbar-width: none; /* Firefox */
    gap: 0;
    padding: 0;
    font-size: 0;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    cursor: grab;
    user-select: none; /* Prevent text selection during drag */
    /* CLS Prevention: Reserve space and optimize rendering */
    min-height: 50vh;
    contain: layout style paint;
    will-change: scroll-position;
    
    /* Hide scrollbar for Webkit browsers */
    &::-webkit-scrollbar {
        display: none;
    }
}

.ica-slider-track:active {
    cursor: grabbing;
}

/* Smooth scrolling for users who prefer motion */
@media (prefers-reduced-motion: no-preference) {
    .ica-slider-track {
        scroll-behavior: smooth;
    }
}

/* ==========================================================================
   Responsive Grid Columns
   ========================================================================== */

/* Mobile: 1 image per view */
.ica-slider-track {
    grid-auto-columns: 100%;
}

/* Tablet: 2 images per view */
@media (min-width: 768px) {
    .ica-slider-track {
        grid-auto-columns: 50%;
    }
}

/* Desktop: 3 images per view */
@media (min-width: 1200px) {
    .ica-slider-track {
        grid-auto-columns: 33.333333%;
    }
}

/* ==========================================================================
   Slider Items
   ========================================================================== */

/* Hide cloned slides from screen readers */
.ica-slider-item--clone {
    /* Cloned slides are hidden from screen readers */
}

.ica-slider-item--clone[aria-hidden="true"] {
    /* Ensure cloned slides are completely hidden from assistive technology */
}

.ica-slider-item {
    height: 50vh; /* Increased height */
    scroll-snap-align: start;
    position: relative;
    overflow: hidden;
    margin: 0;
    padding: 0;
    border: none;
    border-radius: 0;
    /* CLS Prevention: Reserve space and optimize rendering */
    min-height: 50vh;
    contain: layout style paint;
}
.ica-slider-item__img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    margin: 0;
    padding: 0;
    border: none;
    border-radius: 0;
    outline: none;
    /* LCP Optimization: Prevent layout shift during image load */
    aspect-ratio: 4/3; /* Maintain aspect ratio to prevent CLS */
    background-color: #f5f5f5; /* Placeholder color while loading */
    /* Performance optimization */
    contain: layout style paint;
}

.ica-slider-item:hover .ica-slider-item__img {
    transform: none; /* Remove hover scale effect */
}

/* ==========================================================================
   Navigation Controls - Performance Optimized
   ========================================================================== */

.ica-slider-navigation {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none; /* Allow clicks to pass through to buttons */
    z-index: 10;
}

.ica-slider-section--gallery .ica-slider-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.9);
    color: var(--ica-green-deep, #03332E);
    border: 1px solid rgba(0, 0, 0, 0.08);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.14);
    z-index: 10;
    cursor: pointer;
    transition: all 0.2s ease;
    pointer-events: auto; /* Re-enable pointer events for buttons */
    contain: layout style paint;
}

.ica-slider-section--gallery .ica-slider-nav:hover {
    background: rgba(255, 255, 255, 1);
    transform: translateY(-50%) scale(1.05);
    box-shadow: 0 15px 25px rgba(0, 0, 0, 0.2);
    will-change: transform, background-color; /* Only on hover when needed */
}

.ica-slider-section--gallery .ica-slider-nav:active {
    transform: translateY(-50%) scale(0.95);
}

.ica-slider-section--gallery .ica-slider-nav:focus {
    outline: 2px solid var(--ica-green-deep, #03332E);
    outline-offset: 2px;
}

.ica-slider-section--gallery .ica-slider-nav--prev {
    left: 1rem;
}

.ica-slider-section--gallery .ica-slider-nav--next {
    right: 1rem;
}

.ica-slider-section--gallery .ica-slider-nav span {
    font-size: 18px;
    font-weight: bold;
    line-height: 1;
}

/* Hide navigation on very small screens */
@media (max-width: 480px) {
    .ica-slider-section--gallery .ica-slider-nav {
        display: none;
    }
}


/* ==========================================================================
   Progress Bar
   ========================================================================== */

.ica-progress-container {
    position: absolute;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    width: 200px;
    height: 4px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 2px;
    overflow: hidden;
    z-index: 10;
}

.ica-progress-bar {
    height: 100%;
    background: var(--ica-green-deep, #03332E);
    border-radius: 2px;
    width: 0%;
    transition: width 0.3s ease;
}

/* ==========================================================================
   Accessibility & Motion Preferences
   ========================================================================== */

/* Respect user's motion preferences */
@media (prefers-reduced-motion: reduce) {
    .ica-slider-track {
        scroll-behavior: auto;
    }
    
    .ica-slider-item__img {
        transition: none;
    }
    
    .ica-slider-nav__button {
        transition: none;
    }
    
    .ica-progress-bar {
        transition: none;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .ica-slider-nav__button {
        background: white;
        border: 2px solid #000;
    }
    
    .ica-progress-container {
        background: #000;
    }
    
    .ica-progress-bar {
        background: #fff;
    }
}

/* ==========================================================================
   Focus Management
   ========================================================================== */

.ica-slider-wrapper:focus-within .ica-slider-nav__button {
    opacity: 1;
    visibility: visible;
}

/* ==========================================================================
   Loading States - LCP Optimized
   ========================================================================== */

.ica-slider-item__img {
    opacity: 1;
    transition: opacity 0.3s ease;
    /* LCP Optimization: Prevent layout shift */
    background-color: #f5f5f5;
    background-image: linear-gradient(90deg, #f0f0f0 25%, transparent 25%);
    background-size: 20px 20px;
    animation: shimmer 1.5s infinite;
}

.ica-slider-item__img[loading="eager"] {
    /* Critical: First image for LCP */
    opacity: 1;
    background: none;
    animation: none;
}

.ica-slider-item__img[loading="lazy"] {
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.ica-slider-item__img[loading="lazy"].loaded {
    opacity: 1;
    background: none;
    animation: none;
}

/* Shimmer loading animation */
@keyframes shimmer {
    0% { background-position: -200px 0; }
    100% { background-position: calc(200px + 100%) 0; }
}


/* ==========================================================================
   Accessibility - Screen Reader Support
   ========================================================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ==========================================================================
   Core Web Vitals Optimizations
   ========================================================================== */

/* LCP optimization handled in PHP - no CSS interference needed */

/* Reduce motion for accessibility and performance */
@media (prefers-reduced-motion: reduce) {
    .ica-slider-track {
        scroll-behavior: auto;
    }
    
    .ica-slider-item__img {
        animation: none;
    }
    
    .ica-slider-nav {
        transition: none;
    }
}

/* Performance optimization for low-end devices */
@media (max-width: 768px) {
    .ica-slider-section--gallery {
        contain: layout style paint;
    }
    
    .ica-slider-item__img {
        will-change: auto; /* Reduce GPU usage on mobile */
    }
    
    /* Reduce animations on mobile for better performance */
    .ica-slider-nav {
        transition: none;
    }
}

/* High DPI display optimizations - removed incorrect image-rendering */

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    .ica-slider-item__img {
        background-color: #2a2a2a; /* Darker placeholder */
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
    .ica-slider-nav,
    .ica-progress-container {
        display: none;
    }
    
    .ica-slider-track {
        overflow: visible;
        display: block;
    }
    
    .ica-slider-item {
        break-inside: avoid;
        margin-bottom: 1rem;
    }
}