/* ========== PERFORMANCE OPTIMIZATION STYLESHEET ==========
 * This file contains critical performance optimizations for smooth scrolling,
 * fast loading, and better rendering performance
 * 
 * Key improvements:
 * - GPU acceleration with transform3d and will-change
 * - Smooth scroll behavior
 * - Reduced repaints with contain property
 * - Optimized animations with transform-only animations
 * - Efficient scrolling with passive event listeners
 * ======================================================== */

/* ========== GLOBAL PERFORMANCE OPTIMIZATIONS ========== */
html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    background-color: transparent;
}

/* ========== MODAL PERFORMANCE ========== */
.modal {
}

.modal.active {
    /* Only animate opacity, not visibility */
    animation: modalFadeIn 0.2s ease-out forwards;
}

@keyframes modalFadeIn {
    from { 
        opacity: 0;
    }
    to { 
        opacity: 1;
    }
}

.modal-content {
    backface-visibility: hidden;
}

.modal.active .modal-content {
    animation: modalContentSlideIn 0.25s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes modalContentSlideIn {
    from {
        opacity: 0;
        transform: scale(0.95) translateZ(0);
    }
    to {
        opacity: 1;
        transform: scale(1) translateZ(0);
    }
}

/* ========== BUTTON PERFORMANCE ========== */
button, a.btn, .btn {
    will-change: transform, box-shadow;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    contain: layout style;
    transition: background-color 0.2s ease, color 0.2s ease;
}

button:hover, a.btn:hover, .btn:hover {
    /* Use transform instead of box-shadow changes */
    transform: translateZ(0) translateY(-1px);
    will-change: transform;
}

button:active, a.btn:active, .btn:active {
    transform: translateZ(0) translateY(0);
}

/* ========== LINK PERFORMANCE ========== */
a {
    will-change: color;
    backface-visibility: hidden;
}

/* ========== IMAGE PERFORMANCE ========== */
img, svg, video {
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    contain: paint;
}

/* Lazy loaded images */
img[loading="lazy"] {
    contain: paint;
    will-change: opacity;
}

img.loaded {
    animation: imageLoadFade 0.3s ease-out;
}

@keyframes imageLoadFade {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ========== ANIMATION PERFORMANCE ========== */
.fade-in {
    will-change: opacity;
    animation: optimizedFadeIn 0.4s ease-out forwards;
}

.slide-up {
    will-change: opacity, transform;
    animation: optimizedSlideUp 0.5s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes optimizedFadeIn {
    from { 
        opacity: 0;
    }
    to { 
        opacity: 1;
    }
}

@keyframes optimizedSlideUp {
    from { 
        opacity: 0;
        transform: translate3d(0, 20px, 0);
    }
    to { 
        opacity: 1;
        transform: translate3d(0, 0, 0);
    }
}

/* ========== SCROLL PERFORMANCE ========== */
.scroll-container {
    -webkit-overflow-scrolling: touch;
    will-change: scroll-position;
}

/* Smooth scrolling enhancement */
html {
    scroll-behavior: smooth;
    /* Better scrolling performance */
    overflow-y: scroll;
    overflow-x: hidden;
}

/* Optimize scroll containers */
body {
    /* Enable momentum scrolling on iOS */
    -webkit-overflow-scrolling: touch;
    /* Allow normal scroll behavior */
    overscroll-behavior-y: auto;
}

/* Prevent layout shifts during scroll */
main, section, article {
    contain: layout;
}

/* ========== FILTER BUTTONS PERFORMANCE ========== */
.filter-btn {
    will-change: background, color, box-shadow;
    contain: layout style;
    backface-visibility: hidden;
    transition: background 0.15s ease, color 0.15s ease;
}

.filter-btn.active {
    transition: background 0.15s ease, color 0.15s ease, box-shadow 0.15s ease;
}

/* ========== NAVIGATION PERFORMANCE ========== */
.mobile-nav {
    will-change: transform;
    contain: layout style paint;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

.mobile-nav.active {
    transform: translate3d(0, 0, 0);
}

header.tv-topbar {
    contain: layout style;
    will-change: transform;
    backface-visibility: hidden;
}

/* ========== FLASH SALE PERFORMANCE ========== */
.flash-sale-hero {
    contain: layout style paint;
    backface-visibility: hidden;
}

.timebomb-fill {
    will-change: stroke-dashoffset;
    backface-visibility: hidden;
}

.timebomb {
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
}

/* ========== GRID & LAYOUT PERFORMANCE ========== */
.destinations-grid,
.packages-grid,
.footer-grid {
    contain: layout style;
    will-change: contents;
}

.destination-card,
.package-card {
    contain: layout style paint;
    backface-visibility: hidden;
}

/* ========== FORM PERFORMANCE ========== */
.form-control,
.search-input,
.form-control-select {
    will-change: border-color, box-shadow;
    backface-visibility: hidden;
}

.form-control:focus,
.search-input:focus,
.form-control-select:focus {
    transition: border-color 0.1s ease, box-shadow 0.1s ease;
}

/* ========== HERO SECTION PERFORMANCE ========== */
.hero {
    contain: layout style paint;
    backface-visibility: hidden;
}

.hero-search-form {
    contain: layout style;
    backface-visibility: hidden;
}

/* ========== FOOTER PERFORMANCE ========== */
footer {
    contain: layout style paint;
    backface-visibility: hidden;
}

.footer-social a {
    will-change: background, transform;
    transition: background 0.15s ease, transform 0.15s ease;
}

.footer-social a:hover {
    transform: translateZ(0);
}

/* ========== OVERLAY PERFORMANCE ========== */
.overlay,
.tv-menu-overlay {
    will-change: opacity;
    contain: paint;
}

.overlay.active,
.tv-menu-overlay.active {
    animation: overlayFadeIn 0.2s ease-out forwards;
}

@keyframes overlayFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ========== RESPONSIVE PERFORMANCE OPTIMIZATIONS ========== */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
        scroll-behavior: auto !important;
    }
}

/* ========== MOBILE OPTIMIZATION ========== */
@media (max-width: 768px) {
    /* Reduce complexity for mobile devices */
    .flash-badge {
        will-change: auto;
    }

    .fade-in,
    .slide-up {
        animation-duration: 0.3s;
    }

    /* Larger touch targets with GPU acceleration */
    button, a.btn, .btn {
        transform: translateZ(0);
        min-height: 44px;
        min-width: 44px;
    }
}

/* ========== PRINTING OPTIMIZATION ========== */
@media print {
    * {
        will-change: auto !important;
        animation: none !important;
        transition: none !important;
    }
}