/* ============================================================
   image-viewer.css
   Hỗ trợ 2 theme qua CSS class trên overlay:
     .iv-overlay              → light (default)
     .iv-overlay.iv-dark      → dark
   Dùng var(--bg-*, --border, --text-*) từ app.css làm fallback.
   ============================================================ */

/* ── Theme tokens ── */
.iv-overlay {
    /* Light theme defaults */
    --iv-overlay-bg: rgba(15, 15, 20, 0.55);
    --iv-toolbar-bg: var(--bg-primary, #ffffff);
    --iv-toolbar-border: var(--border, #e5e7eb);
    --iv-toolbar-shadow: 0 1px 4px rgba(0,0,0,.06);
    --iv-title-color: var(--text-primary, #111827);
    --iv-muted-color: var(--text-secondary, #6b7280);
    --iv-counter-bg: var(--bg-secondary, #f3f4f6);
    --iv-zoom-bg: var(--bg-secondary, #f3f4f6);
    --iv-zoom-border: var(--border, #e5e7eb);
    --iv-btn-hover-bg: var(--bg-hover, #e5e7eb);
    --iv-btn-color: var(--text-secondary, #6b7280);
    --iv-btn-hover-color: var(--text-primary, #111827);
    --iv-divider: var(--border, #e5e7eb);
    --iv-stage-bg: #ebebeb;
    --iv-checker-color: #ddd;
    --iv-img-shadow: 0 0 0 1px rgba(0,0,0,.06), 0 4px 20px rgba(0,0,0,.15);
    --iv-spinner-track: var(--border, #e5e7eb);
    --iv-spinner-top: #6366f1;
    --iv-nav-bg: var(--bg-primary, #ffffff);
    --iv-nav-border: var(--border, #e5e7eb);
    --iv-nav-color: var(--text-secondary, #6b7280);
    --iv-nav-shadow: 0 2px 8px rgba(0,0,0,.1);
    --iv-thumbs-bg: var(--bg-primary, #ffffff);
    --iv-thumbs-border: var(--border, #e5e7eb);
    --iv-thumb-bg: var(--bg-secondary, #f3f4f6);
    --iv-hint-bg: var(--bg-primary, #ffffff);
    --iv-hint-border: var(--border, #e5e7eb);
    --iv-hint-color: var(--text-secondary, #6b7280);
    --iv-hint-dot: var(--border, #d1d5db);
    --iv-hint-shadow: 0 2px 8px rgba(0,0,0,.08);
    --iv-accent: #6366f1;
}

    /* Dark variant — thêm class iv-dark vào overlay */
    .iv-overlay.iv-dark {
        --iv-overlay-bg: rgba(8, 8, 10, 0.92);
        --iv-toolbar-bg: rgba(18, 18, 22, 0.95);
        --iv-toolbar-border: rgba(255,255,255,.1);
        --iv-toolbar-shadow: none;
        --iv-title-color: rgba(255,255,255,.88);
        --iv-muted-color: rgba(255,255,255,.45);
        --iv-counter-bg: rgba(255,255,255,.08);
        --iv-zoom-bg: rgba(255,255,255,.07);
        --iv-zoom-border: rgba(255,255,255,.12);
        --iv-btn-hover-bg: rgba(255,255,255,.12);
        --iv-btn-color: rgba(255,255,255,.55);
        --iv-btn-hover-color: #ffffff;
        --iv-divider: rgba(255,255,255,.12);
        --iv-stage-bg: #1a1a1e;
        --iv-checker-color: #232328;
        --iv-img-shadow: 0 8px 40px rgba(0,0,0,.6), 0 2px 8px rgba(0,0,0,.4);
        --iv-spinner-track: rgba(255,255,255,.1);
        --iv-spinner-top: rgba(255,255,255,.7);
        --iv-nav-bg: rgba(30,30,36,.85);
        --iv-nav-border: rgba(255,255,255,.15);
        --iv-nav-color: rgba(255,255,255,.7);
        --iv-nav-shadow: 0 2px 12px rgba(0,0,0,.4);
        --iv-thumbs-bg: rgba(18,18,22,.95);
        --iv-thumbs-border: rgba(255,255,255,.08);
        --iv-thumb-bg: rgba(255,255,255,.06);
        --iv-hint-bg: rgba(20,20,26,.9);
        --iv-hint-border: rgba(255,255,255,.1);
        --iv-hint-color: rgba(255,255,255,.45);
        --iv-hint-dot: rgba(255,255,255,.2);
        --iv-hint-shadow: 0 2px 12px rgba(0,0,0,.3);
        --iv-accent: #818cf8;
    }

/* ── Overlay ── */
.iv-overlay {
    position: fixed;
    inset: 0;
    z-index: 9000;
    display: flex;
    flex-direction: column;
    background: rgba(0, 0, 0, 0);
    transition: background 0.22s ease;
    outline: none;
    user-select: none;
}

    .iv-overlay.iv-visible {
        background: var(--iv-overlay-bg);
    }

/* ── Toolbar ── */
.iv-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 0 12px;
    height: 52px;
    background: var(--iv-toolbar-bg);
    border-bottom: 1px solid var(--iv-toolbar-border);
    box-shadow: var(--iv-toolbar-shadow);
    flex-shrink: 0;
    transform: translateY(-52px);
    opacity: 0;
    transition: transform 0.22s cubic-bezier(.25,.46,.45,.94), opacity 0.22s ease;
}

.iv-visible .iv-toolbar {
    transform: translateY(0);
    opacity: 1;
}

.iv-toolbar-left, .iv-toolbar-right {
    display: flex;
    align-items: center;
    gap: 6px;
    min-width: 140px;
}

.iv-toolbar-right {
    justify-content: flex-end;
}

.iv-title {
    font-size: 13px;
    font-weight: 500;
    color: var(--iv-title-color);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 260px;
}

.iv-counter {
    font-size: 11px;
    color: var(--iv-muted-color);
    font-variant-numeric: tabular-nums;
    background: var(--iv-counter-bg);
    padding: 2px 8px;
    border-radius: 10px;
    white-space: nowrap;
    flex-shrink: 0;
}

/* Zoom controls */
.iv-zoom-controls {
    display: flex;
    align-items: center;
    gap: 2px;
    background: var(--iv-zoom-bg);
    border: 1px solid var(--iv-zoom-border);
    border-radius: 10px;
    padding: 3px;
}

.iv-tool-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    border-radius: 7px;
    cursor: pointer;
    color: var(--iv-btn-color);
    transition: background 0.12s, color 0.12s;
    text-decoration: none;
    flex-shrink: 0;
    font-family: inherit;
}

    .iv-tool-btn:hover {
        background: var(--iv-btn-hover-bg);
        color: var(--iv-btn-hover-color);
    }

    .iv-tool-btn:disabled {
        opacity: .35;
        cursor: not-allowed;
    }

.iv-zoom-display {
    min-width: 52px;
    width: auto;
    font-size: 11px;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    letter-spacing: .01em;
    color: var(--iv-title-color);
}

.iv-divider {
    width: 1px;
    height: 18px;
    background: var(--iv-divider);
    margin: 0 2px;
    flex-shrink: 0;
}

.iv-close-btn:hover {
    background: rgba(239,68,68,.15) !important;
    color: #dc2626 !important;
}

.iv-dark .iv-close-btn:hover {
    background: rgba(239,68,68,.25) !important;
    color: #fca5a5 !important;
}

/* ── Stage ── */
.iv-stage {
    flex: 1;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    cursor: grab;
    background-color: var(--iv-stage-bg);
    background-image: linear-gradient(45deg, var(--iv-checker-color) 25%, transparent 25%), linear-gradient(-45deg, var(--iv-checker-color) 25%, transparent 25%), linear-gradient(45deg, transparent 75%, var(--iv-checker-color) 75%), linear-gradient(-45deg, transparent 75%, var(--iv-checker-color) 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

    .iv-stage:active {
        cursor: grabbing;
    }

/* ── Image wrap ── */
.iv-img-wrap {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    transform-origin: center center;
    will-change: transform;
}

.iv-img {
    display: block;
    max-width: min(90vw, 1400px);
    max-height: calc(100vh - 128px);
    object-fit: contain;
    border-radius: 2px;
    box-shadow: var(--iv-img-shadow);
    opacity: 0;
    transition: opacity 0.18s ease;
    pointer-events: none;
    -webkit-user-drag: none;
    user-select: none;
    background: #ffffff;
}

    .iv-img.iv-img-loaded {
        opacity: 1;
    }

/* Spinner */
.iv-img-loader {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 80px;
    min-height: 80px;
    position: absolute;
    z-index: 1;
    pointer-events: none;
    transition: opacity 0.15s;
}

    .iv-img-loader.iv-hidden {
        opacity: 0;
        pointer-events: none;
    }

.iv-spinner {
    width: 28px;
    height: 28px;
    border: 2.5px solid var(--iv-spinner-track);
    border-top-color: var(--iv-spinner-top);
    border-radius: 50%;
    animation: iv-spin 0.7s linear infinite;
}

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

/* ── Nav arrows ── */
.iv-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid var(--iv-nav-border);
    background: var(--iv-nav-bg);
    border-radius: 50%;
    cursor: pointer;
    color: var(--iv-nav-color);
    box-shadow: var(--iv-nav-shadow);
    transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.15s, box-shadow 0.15s;
}

    .iv-nav:hover {
        background: var(--iv-btn-hover-bg);
        border-color: var(--iv-accent);
        color: var(--iv-accent);
        box-shadow: 0 4px 12px rgba(99,102,241,.2);
    }

.iv-nav-prev {
    left: 14px;
}

.iv-nav-next {
    right: 14px;
}

.iv-nav-prev:hover {
    transform: translateY(-50%) translateX(-1px);
}

.iv-nav-next:hover {
    transform: translateY(-50%) translateX(1px);
}

.iv-nav-disabled {
    opacity: .25;
    cursor: not-allowed;
    pointer-events: none;
}

/* ── Thumbnails ── */
.iv-thumbs {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    height: 72px;
    background: var(--iv-thumbs-bg);
    border-top: 1px solid var(--iv-thumbs-border);
    overflow-x: auto;
    flex-shrink: 0;
    transform: translateY(72px);
    opacity: 0;
    transition: transform 0.22s cubic-bezier(.25,.46,.45,.94) 0.06s, opacity 0.22s ease 0.06s;
}

.iv-visible .iv-thumbs {
    transform: translateY(0);
    opacity: 1;
}

.iv-thumbs::-webkit-scrollbar {
    height: 3px;
}

.iv-thumbs::-webkit-scrollbar-track {
    background: transparent;
}

.iv-thumbs::-webkit-scrollbar-thumb {
    background: var(--iv-divider);
    border-radius: 2px;
}

.iv-thumb {
    flex-shrink: 0;
    width: 52px;
    height: 52px;
    border-radius: 6px;
    overflow: hidden;
    border: 2px solid transparent;
    cursor: pointer;
    background: var(--iv-thumb-bg);
    padding: 0;
    opacity: .5;
    transition: border-color 0.12s, opacity 0.12s, transform 0.12s;
}

    .iv-thumb:hover {
        opacity: .85;
        transform: scale(1.06);
    }

    .iv-thumb.active {
        border-color: var(--iv-accent);
        opacity: 1;
    }

    .iv-thumb img {
        width: 100%;
        height: 100%;
        object-fit: cover;
        display: block;
        pointer-events: none;
        background: #ffffff;
    }

/* ── Hint bar ── */
.iv-hint {
    position: absolute;
    bottom: 88px;
    left: 50%;
    transform: translateX(-50%) translateY(6px);
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 5px 14px;
    background: var(--iv-hint-bg);
    border: 1px solid var(--iv-hint-border);
    border-radius: 20px;
    font-size: 11px;
    color: var(--iv-hint-color);
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s, transform 0.3s;
    box-shadow: var(--iv-hint-shadow);
}

    .iv-hint.iv-hint-show {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }

.iv-hint-dot {
    width: 3px;
    height: 3px;
    border-radius: 50%;
    background: var(--iv-hint-dot);
    flex-shrink: 0;
}

/* No thumbnail strip */
.iv-overlay:not(:has(.iv-thumbs)) .iv-hint {
    bottom: 20px;
}

/* ── Touch ── */
@media (hover: none) {
    .iv-nav {
        display: flex !important;
        opacity: 1;
    }

    .iv-hint {
        display: none;
    }
}

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
    .iv-toolbar, .iv-thumbs, .iv-img {
        transition: none;
    }
}