/* ============================================================================
   Affiliate Materials Hub — Public styles
   Aesthetic: editorial + tool. Instrument Serif display, Manrope body,
   JetBrains Mono for labels. Navy + green. Generous negative space.
   ============================================================================ */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

:root {
    --border: rgba(255, 255, 255, 0.07);
    --border-strong: rgba(255, 255, 255, 0.14);
    --surface-2: rgba(255, 255, 255, 0.025);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.32);
    --radius: 12px;
    --radius-sm: 8px;
    --sidebar-w: 260px;
    --topbar-h: 56px;
}

body {
    font-family: 'Lato', system-ui, -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-feature-settings: 'ss01', 'ss02', 'cv01';
    overflow-x: hidden;
}

/* Subtle atmospheric background */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(900px 600px at 15% 0%, color-mix(in srgb, var(--accent) 8%, transparent) 0%, transparent 60%),
        radial-gradient(700px 500px at 90% 100%, color-mix(in srgb, var(--accent) 5%, transparent) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

/* Light theme */
body.light {
    --bg: #fafaf7;
    --surface: #ffffff;
    --text: #0c1427;
    --text-muted: #5a6478;
    --border: rgba(12, 20, 39, 0.08);
    --border-strong: rgba(12, 20, 39, 0.15);
    --surface-2: rgba(12, 20, 39, 0.02);
    --shadow: 0 8px 32px rgba(12, 20, 39, 0.07);
}

/* ============================================================================
   App shell
   ============================================================================ */
.app {
    display: grid;
    grid-template-columns: var(--sidebar-w) 1fr;
    min-height: 100vh;
    position: relative;
    z-index: 1;
}

/* ============================================================================
   Sidebar
   ============================================================================ */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-w);
    height: 100vh;
    background: color-mix(in srgb, var(--bg) 96%, black 4%);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 1.5rem 1rem 1rem;
    z-index: 20;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0 0.5rem;
    margin-bottom: 1.75rem;
    text-decoration: none;
    color: inherit;
    transition: opacity 0.15s;
}
a.sidebar-brand:hover { opacity: 0.82; }

.sidebar-brand.has-logo {
    padding: 0.25rem 0.5rem;
    justify-content: flex-start;
}
.brand-logo {
    max-width: 100%;
    max-height: 44px;
    height: auto;
    object-fit: contain;
    display: block;
}

.brand-mark {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background:
        linear-gradient(135deg, var(--accent) 0%, color-mix(in srgb, var(--accent) 60%, black) 100%);
    box-shadow: 0 0 24px color-mix(in srgb, var(--accent) 40%, transparent);
    position: relative;
    flex-shrink: 0;
}
.brand-mark::after {
    content: '';
    position: absolute;
    inset: 6px;
    border-radius: 4px;
    background: var(--bg);
    opacity: 0.35;
}
.brand-text {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
    min-width: 0;
}
.brand-name {
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: -0.01em;
    color: var(--text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.brand-sub {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.68rem;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-top: 2px;
}

/* Search */
.sidebar-search {
    position: relative;
    margin-bottom: 1.5rem;
}
.sidebar-search .search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    width: 14px;
    height: 14px;
    color: var(--text-muted);
    pointer-events: none;
}
#search {
    width: 100%;
    height: 36px;
    padding: 0 2rem 0 2.1rem;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-family: inherit;
    font-size: 0.85rem;
    transition: border-color 0.15s, background 0.15s;
}
#search::placeholder { color: var(--text-muted); }
#search:focus {
    outline: none;
    border-color: var(--accent);
    background: color-mix(in srgb, var(--accent) 5%, var(--surface-2));
}
.search-clear {
    position: absolute;
    right: 0.5rem;
    top: 50%;
    transform: translateY(-50%);
    width: 22px;
    height: 22px;
    border: none;
    background: var(--border);
    color: var(--text);
    border-radius: 50%;
    font-size: 1rem;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}
.search-clear:hover { background: var(--border-strong); }

/* Nav */
.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    margin: 0 -0.25rem;
    padding: 0 0.25rem;
}
.sidebar-nav::-webkit-scrollbar { width: 4px; }
.sidebar-nav::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 2px; }

.nav-label {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-muted);
    padding: 0 0.5rem;
    margin-bottom: 0.4rem;
}

.nav-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 0.55rem 0.75rem;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-family: inherit;
    font-size: 0.88rem;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    position: relative;
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item > span:first-child {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.nav-count {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.72rem;
    font-weight: 500;
    color: var(--text-muted);
    background: var(--surface-2);
    padding: 2px 7px;
    border-radius: 4px;
    flex-shrink: 0;
    margin-left: 0.5rem;
}
.nav-item.active {
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    color: var(--accent);
}
.nav-item.active .nav-count {
    background: color-mix(in srgb, var(--accent) 18%, transparent);
    color: var(--accent);
}
.nav-item.active::before {
    content: '';
    position: absolute;
    left: -1rem;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 20px;
    background: var(--accent);
    border-radius: 0 2px 2px 0;
}

/* Sidebar foot */
.sidebar-foot {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface-2);
    color: var(--text-muted);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
    flex-shrink: 0;
}
.icon-btn:hover { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 40%, transparent); background: color-mix(in srgb, var(--accent) 6%, transparent); }
.icon-btn .sun { display: none; }
body.light .icon-btn .sun { display: block; }
body.light .icon-btn .moon { display: none; }

.sidebar-link {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    height: 36px;
    padding: 0 0.75rem;
    background: var(--accent);
    color: var(--bg);
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.8rem;
    letter-spacing: -0.005em;
    text-decoration: none;
    transition: background 0.15s, transform 0.15s;
    min-width: 0;
}
.sidebar-link:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}
.sidebar-link span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ============================================================================
   Mobile topbar
   ============================================================================ */
.topbar {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--topbar-h);
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    align-items: center;
    padding: 0 1rem;
    gap: 0.75rem;
    z-index: 15;
}
.menu-toggle {
    width: 36px;
    height: 36px;
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
}
.menu-toggle:hover { background: var(--surface-2); }
.topbar-brand {
    flex: 1;
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: -0.01em;
}
.topbar-logo {
    flex: 0 1 auto;
    max-height: 32px;
    max-width: 140px;
    width: auto;
    object-fit: contain;
    margin-right: auto;
}

/* ============================================================================
   Main
   ============================================================================ */
.main {
    grid-column: 2;
    padding: 2rem 2.5rem 8rem;
    max-width: 1400px;
    animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.main-head { margin-bottom: 3rem; }

.main-title {
    font-family: 'Lato', system-ui, sans-serif;
    font-weight: 700;
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    letter-spacing: -0.025em;
    line-height: 1.1;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.main-sub {
    font-size: 0.9rem;
    color: var(--text-muted);
    letter-spacing: 0.005em;
}

/* ============================================================================
   Category section
   ============================================================================ */
.cat {
    margin-bottom: 4rem;
    animation: fadeIn 0.5s ease backwards;
}
.cat:nth-child(2) { animation-delay: 0.05s; }
.cat:nth-child(3) { animation-delay: 0.1s; }
.cat:nth-child(4) { animation-delay: 0.15s; }

.cat-head {
    display: flex;
    align-items: baseline;
    gap: 1rem;
    padding-bottom: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}
.cat-num {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
    letter-spacing: 0.05em;
}
.cat-title {
    font-family: 'Lato', system-ui, sans-serif;
    font-weight: 700;
    font-size: clamp(1.2rem, 2.4vw, 1.5rem);
    letter-spacing: -0.015em;
    line-height: 1.1;
    color: var(--text);
    flex: 1;
}
.cat-meta {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.72rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.cat-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: -1rem;
    margin-bottom: 1.5rem;
    max-width: 60ch;
}

/* ============================================================================
   Grid + items
   ============================================================================ */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
    gap: 1rem;
}

.item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform 0.2s cubic-bezier(.2, .8, .2, 1), border-color 0.2s, box-shadow 0.2s;
    position: relative;
    display: flex;
    flex-direction: column;
}
.item:hover {
    transform: translateY(-2px);
    border-color: color-mix(in srgb, var(--accent) 35%, transparent);
    box-shadow: var(--shadow);
}
.item.selected {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent), var(--shadow);
}

/* Media area */
.item-media {
    position: relative;
    aspect-ratio: 4 / 3;
    background-color: rgba(255, 255, 255, 0.02);
    background-image:
        linear-gradient(45deg, rgba(255,255,255,0.025) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(255,255,255,0.025) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, rgba(255,255,255,0.025) 75%),
        linear-gradient(-45deg, transparent 75%, rgba(255,255,255,0.025) 75%);
    background-size: 14px 14px;
    background-position: 0 0, 0 7px, 7px -7px, -7px 0px;
    border-bottom: 1px solid var(--border);
    overflow: hidden;
    cursor: zoom-in;
}
body.light .item-media {
    background-color: #f7f7f3;
    background-image:
        linear-gradient(45deg, rgba(0,0,0,0.025) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(0,0,0,0.025) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, rgba(0,0,0,0.025) 75%),
        linear-gradient(-45deg, transparent 75%, rgba(0,0,0,0.025) 75%);
}
.item-media img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 0.75rem;
    transition: transform 0.3s cubic-bezier(.2, .8, .2, 1);
}
.item:hover .item-media img { transform: scale(1.03); }

.item-media[data-is-image="0"] {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-2);
    background-image: none;
}
.item-file-icon { color: var(--text-muted); }

/* Overlays inside media */
.format-badge {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.65rem;
    font-weight: 600;
    color: var(--text);
    background: rgba(10, 22, 40, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    padding: 3px 6px;
    border-radius: 4px;
    letter-spacing: 0.04em;
    pointer-events: none;
}
body.light .format-badge {
    background: rgba(255, 255, 255, 0.85);
    color: var(--text);
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}

.item-check {
    position: absolute;
    top: 0.5rem;
    left: 0.5rem;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.15s;
}
.item:hover .item-check,
.item.selected .item-check { opacity: 1; }

.item-checkbox {
    position: absolute;
    opacity: 0;
    width: 100%;
    height: 100%;
    margin: 0;
    cursor: pointer;
    z-index: 2;
}
.item-check-box {
    display: block;
    width: 20px;
    height: 20px;
    background: rgba(10, 22, 40, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1.5px solid rgba(255, 255, 255, 0.4);
    border-radius: 5px;
    transition: all 0.15s;
    position: relative;
}
body.light .item-check-box {
    background: rgba(255, 255, 255, 0.9);
    border-color: rgba(12, 20, 39, 0.3);
}
.item-checkbox:checked + .item-check-box {
    background: var(--accent);
    border-color: var(--accent);
}
.item-checkbox:checked + .item-check-box::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 6px;
    width: 4px;
    height: 9px;
    border: solid var(--bg);
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.item-zoom {
    position: absolute;
    bottom: 0.5rem;
    right: 0.5rem;
    width: 28px;
    height: 28px;
    border: none;
    background: rgba(10, 22, 40, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: var(--text);
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.15s, transform 0.15s;
}
body.light .item-zoom {
    background: rgba(255, 255, 255, 0.9);
    color: var(--text);
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
}
.item:hover .item-zoom { opacity: 1; }
.item-zoom:hover { transform: scale(1.08); }

/* Info row */
.item-info {
    padding: 0.75rem 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: space-between;
}
.item-meta {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
    min-width: 0;
    flex: 1;
}
.item-name {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.005em;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.item-details {
    display: flex;
    gap: 0.3rem;
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.68rem;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

.item-dl {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--text-muted);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    flex-shrink: 0;
    transition: all 0.15s;
}
.item-dl:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--bg);
    transform: translateY(-1px);
}

/* ============================================================================
   Selection bar (floating)
   ============================================================================ */
.selection-bar {
    position: fixed;
    bottom: 1.5rem;
    left: 50%;
    transform: translateX(-50%) translateY(calc(100% + 2rem));
    background: color-mix(in srgb, var(--surface) 94%, var(--text));
    border: 1px solid var(--border-strong);
    border-radius: 100px;
    padding: 0.5rem 0.5rem 0.5rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
    transition: transform 0.3s cubic-bezier(.2, .8, .2, 1);
    z-index: 50;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}
.selection-bar.visible { transform: translateX(-50%) translateY(0); }
body.light .selection-bar {
    background: rgba(255,255,255,0.96);
    border-color: var(--border-strong);
    box-shadow: 0 16px 48px rgba(12,20,39,0.2);
}

.sel-count {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.005em;
    padding-right: 0.25rem;
}
.sel-count #selCount { color: var(--accent); }

.sel-btn {
    padding: 0.55rem 1rem;
    border-radius: 100px;
    border: none;
    font-family: inherit;
    font-weight: 600;
    font-size: 0.82rem;
    cursor: pointer;
    transition: all 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}
.sel-btn-ghost {
    background: transparent;
    color: var(--text-muted);
}
.sel-btn-ghost:hover { color: var(--text); background: var(--surface-2); }
.sel-btn-primary {
    background: var(--accent);
    color: var(--bg);
}
.sel-btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

/* Download-all FAB (top right) */
.download-all-fab {
    position: fixed;
    top: 1.5rem;
    right: 2rem;
    height: 38px;
    padding: 0 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    font-weight: 600;
    font-size: 0.82rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    transition: all 0.15s;
    z-index: 10;
}
.download-all-fab:hover {
    background: var(--accent);
    color: var(--bg);
    border-color: var(--accent);
}

/* ============================================================================
   Empty states
   ============================================================================ */
.empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 2rem;
    color: var(--text-muted);
}
.empty-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--surface-2);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--text-muted);
}
.empty h2 {
    font-family: 'Lato', system-ui, sans-serif;
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: -0.015em;
    color: var(--text);
    margin-bottom: 0.5rem;
}
.empty p { font-size: 0.9rem; }

.no-results {
    padding: 4rem 2rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ============================================================================
   Lightbox
   ============================================================================ */
.lightbox {
    position: fixed;
    inset: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    animation: fadeIn 0.2s ease;
}
.lightbox[hidden] { display: none; }

.lightbox-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(5, 12, 25, 0.88);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
body.light .lightbox-backdrop { background: rgba(12, 20, 39, 0.6); }

.lightbox-frame {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: 0 24px 64px rgba(0,0,0,0.5);
    animation: scaleIn 0.25s cubic-bezier(.2, .8, .2, 1);
}
@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.96); }
    to { opacity: 1; transform: scale(1); }
}

.lightbox-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    gap: 1rem;
    flex-shrink: 0;
}
.lightbox-head h3 {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--text);
}
.lightbox-head p {
    font-family: 'Lato', system-ui, sans-serif;
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 2px;
    letter-spacing: 0.04em;
}
.lightbox-actions {
    display: flex;
    gap: 0.5rem;
}
.lightbox-btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.55rem 1rem;
    background: var(--accent);
    color: var(--bg);
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.82rem;
    text-decoration: none;
    transition: background 0.15s;
}
.lightbox-btn-primary:hover { background: var(--accent-hover); }
.lightbox-close {
    width: 36px;
    height: 36px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--text-muted);
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
}
.lightbox-close:hover { color: var(--text); border-color: var(--border-strong); }

.lightbox-body {
    flex: 1;
    overflow: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(255, 255, 255, 0.02);
    background-image:
        linear-gradient(45deg, rgba(255,255,255,0.02) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(255,255,255,0.02) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, rgba(255,255,255,0.02) 75%),
        linear-gradient(-45deg, transparent 75%, rgba(255,255,255,0.02) 75%);
    background-size: 18px 18px;
    background-position: 0 0, 0 9px, 9px -9px, -9px 0px;
    padding: 1.5rem;
    min-height: 300px;
}
body.light .lightbox-body { background-color: #f7f7f3; }
.lightbox-body img {
    max-width: 100%;
    max-height: calc(90vh - 120px);
    object-fit: contain;
}

/* ============================================================================
   Toast
   ============================================================================ */
.toast {
    position: fixed;
    bottom: 5rem;
    left: 50%;
    transform: translateX(-50%) translateY(30px);
    opacity: 0;
    pointer-events: none;
    background: var(--text);
    color: var(--bg);
    padding: 0.75rem 1.25rem;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    z-index: 200;
    transition: all 0.25s cubic-bezier(.2, .8, .2, 1);
    box-shadow: 0 8px 32px rgba(0,0,0,0.25);
}
.toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ============================================================================
   Filtered state
   ============================================================================ */
.cat.hidden, .item.hidden { display: none !important; }

/* ============================================================================
   Responsive
   ============================================================================ */
@media (max-width: 900px) {
    :root { --sidebar-w: 0px; }
    .app { grid-template-columns: 1fr; }
    .topbar { display: flex; }

    .sidebar {
        transform: translateX(-100%);
        width: 280px;
        transition: transform 0.25s cubic-bezier(.2, .8, .2, 1);
        padding-top: 1.25rem;
        box-shadow: 0 0 48px rgba(0,0,0,0.4);
    }
    .sidebar.open { transform: translateX(0); }

    .main {
        grid-column: 1;
        padding: calc(var(--topbar-h) + 1.5rem) 1.25rem 8rem;
    }
    .main-head { margin-bottom: 2rem; }
    .cat-head { flex-wrap: wrap; gap: 0.5rem 1rem; }
    .cat-title { font-size: 1.5rem; }
    .grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 0.75rem; }
    .download-all-fab { top: calc(var(--topbar-h) + 0.5rem); right: 1rem; }

    .selection-bar {
        bottom: 1rem;
        left: 0.75rem;
        right: 0.75rem;
        transform: translateY(calc(100% + 2rem));
        border-radius: 100px;
    }
    .selection-bar.visible { transform: translateY(0); }
}

/* Overlay for sidebar on mobile */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 18;
    opacity: 0;
    transition: opacity 0.25s;
}
.sidebar-overlay.visible {
    display: block;
    opacity: 1;
}