:root {
    --bg: #0f1117;
    --bg2: #1a1520;
    --border: #3a2030;
    --accent: #780032;
    --text: #f0eaed;
    --text-muted: #9e8a92;
    --radius: 10px;
}

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

body.viewer-body {
    background: #111318;
    color: var(--text);
    font-family: 'Segoe UI', system-ui, sans-serif;
    display: flex;
    flex-direction: column;
    min-height: 100dvh;
    padding-bottom: env(safe-area-inset-bottom, 0px);
}

/* ── Header ─────────────────────────────────────────────────────────────── */
.viewer-header {
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    overflow: hidden;
}
.back-link { color: var(--text-muted); font-size: 0.85rem; white-space: nowrap; }
.back-link:hover { color: var(--text); }
.brand-label { color: var(--text-muted); font-size: 0.95rem; font-weight: 600; white-space: nowrap; display: flex; align-items: center; gap: 0.4rem; }
.header-logo { height: 22px; width: auto; object-fit: contain; }
.viewer-title { font-size: 1rem; font-weight: 600; flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.viewer-actions { display: flex; gap: 0.5rem; flex-shrink: 0; }
.viewer-actions .btn-sm, .viewer-actions a.btn-sm {
    background: var(--bg2); border: 1px solid var(--border); color: var(--text);
    border-radius: 6px; padding: 4px 12px; font-size: 0.78rem; cursor: pointer;
    text-decoration: none; white-space: nowrap; display: inline-flex; align-items: center;
}
.viewer-actions .btn-sm:hover, .viewer-actions a.btn-sm:hover { background: var(--border); }

/* ── Flipbook area ──────────────────────────────────────────────────────── */
.flipbook-clip {
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-height: 0; /* let flex size it — 400px caused overflow in landscape */
}

.flipbook-wrapper {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem 0;   /* no horizontal padding — StPageFlip measures clientWidth which includes padding */
    overflow: hidden;
    transform-origin: center center;
    will-change: transform;
}

#flipbook {
    box-shadow: 0 10px 60px rgba(0,0,0,0.7);
    transition: transform 0.7s ease;
}

.flipbook-wrapper.single-page-mode {
    justify-content: center;
}
.flipbook-wrapper.single-page-mode #flipbook {
    margin: 0 auto;
}

.page {
    background: #fff;
    overflow: hidden;
}
.page img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}

/* ── Edge navigation arrows ─────────────────────────────────────────────── */
/* position:fixed so they're always on-screen regardless of flex/overflow/fullscreen quirks.
   JS sets the `top` value to track the vertical midpoint of the canvas area. */
.edge-btn {
    position: fixed;
    top: 50vh; /* JS overrides this on init/resize */
    transform: translateY(-50%);
    z-index: 500;
    background: rgba(26, 21, 32, 0.82);
    border: 1px solid var(--border);
    color: var(--text);
    width: 44px;
    height: 72px;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(6px);
    transition: background 0.15s;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
}
.edge-btn:hover, .edge-btn:active { background: rgba(120, 0, 50, 0.85); }
.edge-btn-prev { left: 0; border-radius: 0 10px 10px 0; border-left: none; }
.edge-btn-next { right: 0; border-radius: 10px 0 0 10px; border-right: none; }

/* Native fullscreen: hide chrome, darken background */
body.native-fs-active .viewer-header,
body.native-fs-active .viewer-controls,
body.native-fs-active .share-panel { display: none; }
body.native-fs-active .flipbook-clip { background: #0a0a0d; }

/* ── Controls ───────────────────────────────────────────────────────────── */
.viewer-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 0.75rem;
    background: var(--bg2);
    border-top: 1px solid var(--border);
    overflow: hidden;
}
.ctrl-btn {
    background: var(--bg2); border: 1px solid var(--border); color: var(--text);
    border-radius: 8px; width: 40px; height: 36px; font-size: 1rem;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    transition: background 0.15s; text-decoration: none;
}
.ctrl-btn:hover { background: var(--border); }
.pdf-ctrl-link { font-size: 0.72rem; font-weight: 600; letter-spacing: 0.04em; width: auto; padding: 0 10px; }
.page-counter { font-size: 0.85rem; color: var(--text-muted); min-width: 70px; text-align: center; }
.zoom-level { font-size: 0.78rem; color: var(--text-muted); min-width: 38px; text-align: center; cursor: pointer; user-select: none; }
.zoom-level:hover { color: var(--text); }

/* ── Share panel ────────────────────────────────────────────────────────── */
.share-panel {
    background: var(--bg2); border-top: 1px solid var(--border);
    padding: 1rem 1.5rem; font-size: 0.85rem;
    display: flex; flex-direction: column; gap: 0.6rem;
}
.share-row {
    display: flex; align-items: center; gap: 0.6rem;
}
.share-row label { color: var(--text-muted); min-width: 45px; font-size: 0.8rem; }
.share-row input {
    flex: 1; background: #0f1117; border: 1px solid var(--border);
    color: var(--text-muted); border-radius: 6px; padding: 4px 10px;
    font-size: 0.78rem; font-family: monospace;
}
.share-row button {
    background: var(--bg2); border: 1px solid var(--border); color: var(--text);
    border-radius: 6px; padding: 4px 12px; font-size: 0.78rem; cursor: pointer;
    white-space: nowrap;
}
.share-row button:hover { background: var(--border); }

/* ── CSS fake fullscreen (iOS Safari fallback) ──────────────────────────── */
.flipbook-wrapper.fake-fullscreen {
    position: fixed;
    top: 0; left: 0;
    width: 100vw;
    height: 100dvh;
    z-index: 9999;
    background: #0a0a0d;
    padding: 0.5rem;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Landscape: constrain fake-fullscreen width so book fits within viewport height */
@media (orientation: landscape) {
    .flipbook-wrapper.fake-fullscreen {
        width: min(100vw, calc(100dvh / 1.414 * 2));
        left: 50%;
        transform: translateX(-50%);
    }
}

/* Landscape on small screens: shrink chrome so the book gets maximum height */
@media (orientation: landscape) and (max-height: 520px) {
    .flipbook-wrapper { padding: 0.4rem 0; }
    .viewer-header    { padding: 0.4rem 1rem; }
    .viewer-controls  { padding: 0.3rem; }
}

/* Hide Embed Code button in header on narrow phones — it's in the share panel below */
@media (max-width: 480px) {
    .btn-embed { display: none; }
}
/* Hide page chrome while fake-fullscreen is active */
body.fs-active .viewer-header,
body.fs-active .viewer-controls,
body.fs-active .share-panel { display: none; }

/* Floating overlay controls (shown in fake-fullscreen only) */
.fs-overlay {
    display: none;
    position: fixed;
    bottom: max(1rem, env(safe-area-inset-bottom));
    left: 50%; transform: translateX(-50%);
    z-index: 10000;
    background: rgba(10,10,13,0.85);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border);
    border-radius: 40px;
    padding: 0.4rem 0.75rem;
    gap: 0.75rem;
    align-items: center;
}
body.fs-active .fs-overlay { display: flex; }
.fs-btn {
    background: transparent; border: none; color: var(--text);
    font-size: 1.2rem; padding: 0.4rem 0.6rem; cursor: pointer;
    border-radius: 50%; line-height: 1;
}
.fs-btn:active { background: rgba(255,255,255,0.1); }
.fs-close { color: var(--text-muted); font-size: 1rem; margin-left: 0.25rem; }
.fs-counter { font-size: 0.82rem; color: var(--text-muted); min-width: 55px; text-align: center; }

/* ── Embed mode ─────────────────────────────────────────────────────────── */
body.embed-mode {
    background: #0d0e12;
}
body.embed-mode .flipbook-wrapper {
    padding: 0.5rem;
}
body.embed-mode .viewer-controls {
    padding: 0.5rem;
    background: transparent;
    border-top: none;
}