/* ============================================================
   Gallery page — gallery.css
   Masonry grid, shimmer placeholders, lazy-load fade-in,
   hover overlay and focus ring for each media item.
   ============================================================ */

:root {
    --gallery-gap: 0.75rem;
    --gallery-col-min: 240px;
    --gallery-radius: 0.75rem;
    --shimmer-base: rgba(255, 255, 255, 0.05);
    --shimmer-shine: rgba(255, 255, 255, 0.13);
    --overlay-bg: rgba(0, 0, 0, 0.45);
    --overlay-icon-color: rgba(255, 211, 0, 0.95);
}

/* ---- Page header ---- */

.gallery-page__header {
    margin-bottom: 1.75rem;
}

.gallery-page__title {
    font-size: clamp(1.6rem, 1.4rem + 1vw, 2.2rem);
    font-weight: 700;
    letter-spacing: 0.02em;
    margin-bottom: 0.25rem;
}

.gallery-page__subtitle {
    color: var(--bs-secondary-color, #adb5bd);
    margin-bottom: 0;
}

.gallery-page__subnav {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.75rem;
}

.gallery-page__count {
    font-size: 0.85rem;
}

/* ---- Masonry grid via CSS columns ---- */

.gallery-grid {
    columns: var(--gallery-col-min) auto;
    column-gap: var(--gallery-gap);
    orphans: 1;
    widows: 1;
}

/* ---- Individual gallery item ---- */

.gallery-item {
    display: block;
    break-inside: avoid;
    margin-bottom: var(--gallery-gap);
    text-decoration: none;
    border-radius: var(--gallery-radius);
    overflow: hidden;
    /* GPU layer to avoid repaint during transforms */
    will-change: transform;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.gallery-item:hover,
.gallery-item:focus-visible {
    transform: translateY(-3px) scale(1.01);
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.5);
    outline: none;
}

.gallery-item:focus-visible {
    box-shadow:
        0 8px 28px rgba(0, 0, 0, 0.5),
        0 0 0 3px rgba(255, 211, 0, 0.6);
}

/* ---- Inner wrapper (holds aspect-ratio for shimmer reservation) ---- */

.gallery-item__inner {
    position: relative;
    width: 100%;
    overflow: hidden;
    border-radius: var(--gallery-radius);
    /* aspect-ratio is set via inline style from PHP */
    background: rgba(255, 255, 255, 0.04);
}

/* ---- Shimmer placeholder ---- */

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

.gallery-item__shimmer {
    position: absolute;
    inset: 0;
    background: linear-gradient(
        90deg,
        var(--shimmer-base) 25%,
        var(--shimmer-shine) 50%,
        var(--shimmer-base) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.6s linear infinite;
    border-radius: var(--gallery-radius);
    z-index: 1;
    opacity: 1;
    transition: opacity 0.35s ease;
}

.gallery-item__inner.is-loaded .gallery-item__shimmer {
    opacity: 0;
    pointer-events: none;
}

/* ---- Lazy-loaded image ---- */

.gallery-item__img {
    display: block;
    width: 100%;
    height: auto;
    opacity: 0;
    transition: opacity 0.4s ease;
    position: relative;
    z-index: 2;
    border-radius: var(--gallery-radius);
}

.gallery-item__inner.is-loaded .gallery-item__img {
    opacity: 1;
}

/* ---- Hover / focus overlay ---- */

.gallery-item__overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--overlay-bg);
    border-radius: var(--gallery-radius);
    opacity: 0;
    transition: opacity 0.22s ease;
    z-index: 3;
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
}

.gallery-item:hover .gallery-item__overlay,
.gallery-item:focus-visible .gallery-item__overlay {
    opacity: 1;
}

.gallery-item__overlay-icon {
    font-size: 2.6rem;
    color: var(--overlay-icon-color);
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.6));
    transform: scale(0.85);
    transition: transform 0.22s ease;
}

.gallery-item:hover .gallery-item__overlay-icon,
.gallery-item:focus-visible .gallery-item__overlay-icon {
    transform: scale(1);
}

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

@media (prefers-reduced-motion: reduce) {
    .gallery-item__shimmer {
        animation: none;
        background: var(--shimmer-base);
    }

    .gallery-item,
    .gallery-item__img,
    .gallery-item__shimmer,
    .gallery-item__overlay,
    .gallery-item__overlay-icon {
        transition: none;
    }
}