/**
 * Virtual Scroller Styles
 *
 * Optimized styles for virtual scrolling performance
 * Maintains smooth 60fps scrolling even with 10,000+ items
 */

/* Container */
.virtual-scroller-container {
    position: relative;
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch; /* Smooth scrolling on iOS */
    will-change: scroll-position;
    height: 600px; /* Default height, can be overridden */
}

/* Scroll content (spacer) */
.virtual-scroll-content {
    position: relative;
    width: 100%;
    pointer-events: none; /* Don't block clicks */
}

/* Viewport (visible items container) */
.virtual-viewport {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    will-change: transform;
    pointer-events: auto; /* Re-enable clicks for items */
}

/* Individual items */
.virtual-item {
    box-sizing: border-box;
    overflow: hidden;
    contain: layout style paint; /* CSS containment for performance */
}

/* Grid layout for virtual items */
.virtual-scroller-container .entity-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    padding: 0 20px;
}

/* List layout for virtual items */
.virtual-scroller-container .entity-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 0 20px;
}

/* Table layout for virtual items */
.virtual-scroller-container .entity-table {
    width: 100%;
    border-collapse: collapse;
}

/* Loading indicator */
.virtual-loading {
    position: sticky;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px;
    text-align: center;
    background: rgba(255, 255, 255, 0.95);
    border-top: 2px solid var(--border-color, #e0e0e0);
    box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.05);
    z-index: 10;
}

.virtual-loading .spinner {
    width: 32px;
    height: 32px;
    margin: 0 auto 12px;
    border: 3px solid var(--border-color, #e0e0e0);
    border-top-color: var(--primary-color, #9370DB);
    border-radius: 50%;
    animation: virtual-spin 0.6s linear infinite;
}

.virtual-loading p {
    margin: 0;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary, #666);
}

@keyframes virtual-spin {
    to { transform: rotate(360deg); }
}

/* Smooth scrolling */
.virtual-scroller-container {
    scroll-behavior: smooth;
}

/* Performance: Use GPU acceleration */
.virtual-viewport,
.virtual-item {
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

/* Custom scrollbar styling */
.virtual-scroller-container::-webkit-scrollbar {
    width: 12px;
}

.virtual-scroller-container::-webkit-scrollbar-track {
    background: var(--secondary-bg, #f5f5f5);
    border-radius: 6px;
}

.virtual-scroller-container::-webkit-scrollbar-thumb {
    background: var(--border-color, #ddd);
    border-radius: 6px;
    transition: background 0.2s;
}

.virtual-scroller-container::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color, #9370DB);
}

/* Firefox scrollbar */
.virtual-scroller-container {
    scrollbar-width: thin;
    scrollbar-color: var(--border-color, #ddd) var(--secondary-bg, #f5f5f5);
}

/* Scroll to top button */
.virtual-scroll-to-top {
    position: sticky;
    bottom: 20px;
    left: 100%;
    transform: translateX(-60px);
    width: 48px;
    height: 48px;
    background: var(--primary-color, #9370DB);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(147, 112, 219, 0.3);
    transition: all 0.3s ease;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
}

.virtual-scroll-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}

.virtual-scroll-to-top:hover {
    transform: translateX(-60px) translateY(-4px);
    box-shadow: 0 6px 20px rgba(147, 112, 219, 0.4);
}

/* Performance indicator (for debugging) */
.virtual-scroller-container.show-performance::before {
    content: attr(data-performance);
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    padding: 8px;
    background: rgba(0, 0, 0, 0.8);
    color: #0f0;
    font-family: monospace;
    font-size: 11px;
    text-align: center;
    z-index: 1000;
    pointer-events: none;
}

/* Responsive adjustments */
@media (max-width: 1024px) {
    .virtual-scroller-container .entity-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 16px;
        padding: 0 16px;
    }
}

@media (max-width: 768px) {
    .virtual-scroller-container {
        height: calc(100vh - 200px); /* Full viewport on mobile */
    }

    .virtual-scroller-container .entity-grid {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 0 12px;
    }

    .virtual-scroller-container .entity-list {
        gap: 12px;
        padding: 0 12px;
    }

    .virtual-scroll-to-top {
        transform: translateX(-20px);
        width: 40px;
        height: 40px;
        font-size: 18px;
    }

    .virtual-scroll-to-top:hover {
        transform: translateX(-20px) translateY(-4px);
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    .virtual-loading {
        background: rgba(42, 42, 62, 0.95);
    }

    .virtual-scroller-container::-webkit-scrollbar-track {
        background: #2a2a3e;
    }

    .virtual-scroller-container::-webkit-scrollbar-thumb {
        background: #404050;
    }

    .virtual-scroller-container::-webkit-scrollbar-thumb:hover {
        background: var(--primary-color, #9370DB);
    }

    .virtual-scroller-container {
        scrollbar-color: #404050 #2a2a3e;
    }
}

/* Print styles - disable virtual scrolling */
@media print {
    .virtual-scroller-container {
        overflow: visible !important;
        height: auto !important;
    }

    .virtual-scroll-content {
        height: auto !important;
    }

    .virtual-viewport {
        position: static !important;
        transform: none !important;
    }

    .virtual-loading,
    .virtual-scroll-to-top {
        display: none !important;
    }
}

/* Accessibility: Reduced motion */
@media (prefers-reduced-motion: reduce) {
    .virtual-scroller-container {
        scroll-behavior: auto;
    }

    .virtual-viewport,
    .virtual-item {
        transition: none !important;
        animation: none !important;
    }
}

/* Performance optimization: Force layer creation */
.virtual-scroller-container {
    transform: translate3d(0, 0, 0);
    isolation: isolate;
}

/* Grid card adjustments for virtual scrolling */
.virtual-scroller-container .grid-card {
    margin: 0; /* Remove margins, use gap instead */
}

.virtual-scroller-container .entity-list-item {
    margin: 0; /* Remove margins, use gap instead */
}

/* Ensure consistent sizing */
.virtual-item > * {
    height: 100%;
    box-sizing: border-box;
}

/* Loading skeleton for initial render */
.virtual-item.skeleton {
    background: linear-gradient(
        90deg,
        var(--secondary-bg, #f5f5f5) 25%,
        var(--hover-bg, #e8e8e8) 50%,
        var(--secondary-bg, #f5f5f5) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
}

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