/* ==========================================================================
   GALLERY ZOOM — Fullscreen Premium Image Viewer
   Luxury fashion e-commerce zoom experience (Zara / COS / Mango tier)
   --------------------------------------------------------------------------
   Depends on: gallery.html structure, Swiper.js (already loaded by host page)
   Namespaced under .gz-* to avoid collisions with the existing gallery CSS.
   ========================================================================== */

:root {
    /* Inherit the host gallery's language; redeclared here so this file
       is self-contained if loaded on its own page. */
    --gz-ink: #111111;
    --gz-paper: #fafafa;
    --gz-overlay-bg: rgba(10, 10, 10, 0.96);
    --gz-glass: rgba(255, 255, 255, 0.08);
    --gz-glass-border: rgba(255, 255, 255, 0.14);
    --gz-glass-hover: rgba(255, 255, 255, 0.16);
    --gz-text: #f5f5f5;
    --gz-text-dim: rgba(245, 245, 245, 0.55);

    /* Premium easing — decelerated, no bounce. This single curve is the
       "house style" for every transition in the viewer. */
    --gz-ease: cubic-bezier(0.16, 1, 0.3, 1);
    --gz-ease-fast: cubic-bezier(0.4, 0, 0.2, 1);

    --gz-radius-lg: 20px;
    --gz-radius-md: 14px;
    --gz-radius-sm: 10px;

    --gz-z: 10000;
}

/* --------------------------------------------------------------------------
   Root overlay
   -------------------------------------------------------------------------- */

.gz-overlay {
    position: fixed;
    inset: 0;
    z-index: var(--gz-z);
    display: none;
    background: var(--gz-overlay-bg);
    -webkit-backdrop-filter: blur(0px);
    backdrop-filter: blur(0px);
    opacity: 0;

    /* Both opacity and blur are animated for the "settling into focus"
       premium feel — flat fades feel cheap. */
    transition: opacity 0.5s var(--gz-ease), backdrop-filter 0.6s var(--gz-ease);
    overscroll-behavior: contain;
}

.gz-overlay.gz-is-open {
    display: flex;
    flex-direction: column;
}

.gz-overlay.gz-is-visible {
    opacity: 1;
    -webkit-backdrop-filter: blur(18px);
    backdrop-filter: blur(18px);
}

/* Closing state plays a slightly faster fade-out than the opening fade-in */
.gz-overlay.gz-is-closing {
    transition: opacity 0.32s var(--gz-ease-fast), backdrop-filter 0.32s var(--gz-ease-fast);
    opacity: 0;
    -webkit-backdrop-filter: blur(0px);
    backdrop-filter: blur(0px);
}

/* Disable page scroll while viewer is open (class applied to <body>) */
body.gz-scroll-lock {
    overflow: hidden;
    height: 100%;
}

/* --------------------------------------------------------------------------
   Top bar: counter + close button
   -------------------------------------------------------------------------- */

.gz-topbar {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px 0;
    flex: 0 0 auto;

    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 0.5s var(--gz-ease) 0.08s, transform 0.5s var(--gz-ease) 0.08s;
}

.gz-overlay.gz-is-visible .gz-topbar {
    opacity: 1;
    transform: translateY(0);
}

.gz-counter {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.04em;
    color: var(--gz-text-dim);
    background: var(--gz-glass);
    border: 1px solid var(--gz-glass-border);
    padding: 8px 16px;
    border-radius: 999px;
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    user-select: none;
    font-variant-numeric: tabular-nums;
}

.gz-icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid var(--gz-glass-border);
    background: var(--gz-glass);
    color: var(--gz-text);
    cursor: pointer;
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.25);
    transition: background 0.25s var(--gz-ease-fast),
        transform 0.25s var(--gz-ease-fast),
        border-color 0.25s var(--gz-ease-fast);
    -webkit-tap-highlight-color: transparent;
}

.gz-icon-btn:hover {
    background: var(--gz-glass-hover);
    border-color: rgba(255, 255, 255, 0.28);
    transform: scale(1.06);
}

.gz-icon-btn:active {
    transform: scale(0.96);
}

.gz-icon-btn svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.gz-icon-btn:focus-visible,
.gz-thumb:focus-visible,
.gz-close:focus-visible {
    outline: 2px solid #fff;
    outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Stage: the popup Swiper that hosts full-resolution images
   -------------------------------------------------------------------------- */

.gz-stage-wrap {
    position: relative;
    flex: 1 1 auto;
    min-height: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.gz-stage {
    width: 100%;
    height: 100%;
}

.gz-stage .swiper-wrapper {
    /* Disable Swiper's default transform transition while a slide is being
       actively panned/zoomed; GalleryZoom toggles a class to manage this. */
    align-items: center;
}

.gz-slide {
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    position: relative;
}

/* Each slide gets its own pan/zoom viewport. Kept separate from Swiper's
   own translateX so the two transforms never fight each other. */
.gz-zoom-viewport {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: zoom-in;
    touch-action: none; /* we own all pan/pinch gestures manually */
}

.gz-zoom-viewport.gz-can-pan {
    cursor: grab;
}

.gz-zoom-viewport.gz-is-panning {
    cursor: grabbing;
}

.gz-zoom-img {
    max-width: 92vw;
    max-height: 86vh;
    width: auto;
    height: auto;
    object-fit: contain;
    user-select: none;
    -webkit-user-drag: none;
    will-change: transform;
    transform: translate3d(0, 0, 0) scale(1);
    opacity: 0;
    transition: opacity 0.45s var(--gz-ease);

    /* GPU-friendly: composite layer, no layout/paint thrash while panning */
    backface-visibility: hidden;
}

.gz-zoom-img.gz-loaded {
    opacity: 1;
}

/* While the user is actively dragging or pinching, suspend the CSS
   transition on the image so JS-driven transform updates via rAF are
   instant — prevents the classic "laggy rubber-band" zoom feel. */
.gz-zoom-img.gz-no-transition {
    transition: none !important;
}

/* --------------------------------------------------------------------------
   Loading spinner (shown briefly while the original-resolution asset loads)
   -------------------------------------------------------------------------- */

.gz-spinner {
    position: absolute;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.18);
    border-top-color: rgba(255, 255, 255, 0.85);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s var(--gz-ease-fast);
}

.gz-spinner.gz-active {
    opacity: 1;
    animation: gz-spin 0.85s linear infinite;
}

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

/* --------------------------------------------------------------------------
   Prev / Next navigation arrows
   -------------------------------------------------------------------------- */

.gz-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 3;

    opacity: 0;
    transition: opacity 0.5s var(--gz-ease) 0.12s, transform 0.3s var(--gz-ease-fast);
}

.gz-overlay.gz-is-visible .gz-nav {
    opacity: 1;
}

.gz-nav-prev {
    left: 20px;
}

.gz-nav-next {
    right: 20px;
}

.gz-nav .gz-icon-btn {
    width: 52px;
    height: 52px;
}

.gz-nav .gz-icon-btn:hover {
    transform: translateY(-50%) scale(1.08);
}

.gz-overlay.gz-is-visible .gz-nav .gz-icon-btn:hover {
    transform: scale(1.08);
}

.gz-nav.gz-disabled {
    opacity: 0 !important;
    pointer-events: none;
}

/* --------------------------------------------------------------------------
   Bottom thumbnail rail
   -------------------------------------------------------------------------- */

.gz-rail-wrap {
    flex: 0 0 auto;
    display: flex;
    justify-content: center;
    padding: 16px 16px 24px;

    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.5s var(--gz-ease) 0.1s, transform 0.5s var(--gz-ease) 0.1s;
}

.gz-overlay.gz-is-visible .gz-rail-wrap {
    opacity: 1;
    transform: translateY(0);
}

.gz-rail {
    display: flex;
    gap: 10px;
    max-width: 100%;
    overflow-x: auto;
    padding: 8px 10px;
    border-radius: var(--gz-radius-lg);
    background: var(--gz-glass);
    border: 1px solid var(--gz-glass-border);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);

    /* Hide scrollbar but keep it scrollable */
    scrollbar-width: none;
}

.gz-rail::-webkit-scrollbar {
    display: none;
}

.gz-thumb {
    flex: 0 0 auto;
    width: 56px;
    height: 70px;
    border-radius: var(--gz-radius-sm);
    overflow: hidden;
    border: 2px solid transparent;
    cursor: pointer;
    opacity: 0.55;
    background: #000;
    transition: opacity 0.3s var(--gz-ease-fast),
        border-color 0.3s var(--gz-ease-fast),
        transform 0.3s var(--gz-ease-fast);
}

.gz-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.gz-thumb:hover {
    opacity: 0.85;
    transform: translateY(-2px);
}

.gz-thumb.gz-active {
    opacity: 1;
    border-color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

/* --------------------------------------------------------------------------
   Responsive adjustments
   -------------------------------------------------------------------------- */

@media (max-width: 768px) {
    .gz-topbar {
        padding: 14px 14px 0;
    }

    .gz-icon-btn {
        width: 40px;
        height: 40px;
    }

    .gz-nav-prev {
        left: 8px;
    }

    .gz-nav-next {
        right: 8px;
    }

    .gz-nav .gz-icon-btn {
        width: 42px;
        height: 42px;
    }

    .gz-zoom-img {
        max-width: 96vw;
        max-height: 78vh;
    }

    .gz-thumb {
        width: 46px;
        height: 58px;
    }

    .gz-rail-wrap {
        padding: 12px 10px 18px;
    }
}

@media (max-width: 420px) {
    .gz-nav {
        display: none; /* swipe is the primary nav gesture at this size */
    }
}

/* --------------------------------------------------------------------------
   Reduced motion
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    .gz-overlay,
    .gz-topbar,
    .gz-nav,
    .gz-rail-wrap,
    .gz-icon-btn,
    .gz-thumb,
    .gz-zoom-img {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}

/* --------------------------------------------------------------------------
   Visually-hidden helper for screen-reader-only text
   -------------------------------------------------------------------------- */

.gz-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;
}