.s3db-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    padding: 30px 0;
    outline: none;
}

.s3db-wrapper.s3db-is-fullscreen {
    background: #000;
    padding: 0;
    justify-content: center;
    height: 100vh;
}

.s3db-stage {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    overflow: hidden;
}

.s3db-stage:fullscreen,
.s3db-stage:-webkit-full-screen {
    box-sizing: border-box;
    padding: 16px;
    background: #000;
}

.s3db-book-container {
    margin: 0 auto;
    /* v1.4.5 — tighter, softer page-edge shadow. Kept deliberately close
       to the physical spread so the viewer does not read as a large box. */
    box-shadow: 0 5px 14px rgba(0, 0, 0, 0.12);
    background-color: #fff;
    border-radius: 4px;
}

.s3db-page {
    background-color: #fcfcfc;
    overflow: hidden;
    box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.05);
}

.s3db-page-content {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.s3db-page-content img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    user-select: none;
    -webkit-user-drag: none;
}

/* Loading spinner shown until the book library initialises */
.s3db-loading {
    position: absolute;
    inset: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(255, 255, 255, 0.6);
}

.s3db-spinner {
    width: 34px;
    height: 34px;
    border: 3px solid rgba(0, 0, 0, 0.15);
    border-top-color: rgba(0, 0, 0, 0.55);
    border-radius: 50%;
    animation: s3db-spin 0.8s linear infinite;
}

@keyframes s3db-spin {
    to {
        transform: rotate(360deg);
    }
}

/* Toolbar: prev/next + counter + fullscreen */
.s3db-toolbar {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-top: 16px;
}

.s3db-btn {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    width: 38px;
    height: 38px;
    border: none;
    border-radius: 50%;
    background: #222;
    color: #fff;
    font-size: 16px;
    line-height: 1;
    cursor: pointer;
    transition: background-color 0.15s ease, transform 0.1s ease;
}

.s3db-btn:hover {
    background: #444;
}

.s3db-btn:active {
    transform: scale(0.94);
}

.s3db-page-count {
    min-width: 64px;
    text-align: center;
    font-size: 14px;
    color: #444;
    font-variant-numeric: tabular-nums;
}

.s3db-error {
    color: #b91c1c;
    text-align: center;
    padding: 15px;
    border: 1px dashed #b91c1c;
    border-radius: 4px;
    max-width: 480px;
    margin: 0 auto;
}

/* Responsive adjustments */
@media (max-width: 767px) {
    .s3db-wrapper {
        padding: 10px 0 14px;
    }

    .s3db-stage {
        min-height: 0;
    }

    .s3db-btn {
        width: 34px;
        height: 34px;
        font-size: 14px;
    }

    .s3db-toolbar {
        gap: 12px;
        margin-top: 10px;
    }
}

/* v1.3.4: center a single cover while PageFlip keeps its landscape two-page canvas. */
.s3db-book-positioner {
    display: inline-block;
    transition: transform 280ms ease;
    will-change: transform;
}

.s3db-book-positioner.s3db-cover-first {
    transform: translateX(-25%);
}

.s3db-book-positioner.s3db-cover-last {
    transform: translateX(25%);
}

@media (max-width: 767px) {
    .s3db-book-positioner.s3db-cover-first,
    .s3db-book-positioner.s3db-cover-last {
        transform: none;
    }
}

/* v1.4.0 navigation hint */
.s3db-nav-hint {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 9px;
    margin-top: 14px;
    padding: 7px 13px;
    border-radius: 999px;
    background: rgba(20, 20, 20, 0.72);
    color: #fff;
    font-size: 13px;
    line-height: 1.2;
    letter-spacing: 0.01em;
    pointer-events: none;
    opacity: 1;
    transform: translateY(0);
    transition: opacity 350ms ease, transform 350ms ease;
}

.s3db-nav-hint.s3db-hint-hidden {
    opacity: 0;
    transform: translateY(5px);
}

.s3db-hint-arrow {
    font-size: 16px;
    opacity: 0.9;
}

@media (max-width: 767px) {
    .s3db-nav-hint {
        font-size: 12px;
        padding: 6px 11px;
        margin-top: 8px;
    }
}

.s3db-wrapper:focus-visible {
    outline: 2px solid currentColor;
    outline-offset: 4px;
}

@media (prefers-reduced-motion: reduce) {
    .s3db-book-positioner,
    .s3db-nav-hint,
    .s3db-btn {
        transition: none !important;
    }
}

/* v1.4.3 — generic automatic end-sheet for odd page counts. */
.s3db-end-page {
    position: relative;
    background: #f7f5f0;
    overflow: hidden;
}

.s3db-end-collage,
.s3db-end-wash,
.s3db-end-cue {
    position: absolute;
    inset: 0;
}

.s3db-end-collage {
    transform: scale(1.04);
    filter: blur(1.6px) saturate(.72) contrast(.92);
    opacity: .72;
}

.s3db-end-tile {
    position: absolute;
    width: 52%;
    height: 40%;
    background-size: cover;
    background-position: center;
    border: 4px solid rgba(255,255,255,.82);
    box-shadow: 0 10px 25px rgba(0,0,0,.10);
}
.s3db-end-tile-1 { left: -7%; top: -6%; transform: rotate(-6deg); }
.s3db-end-tile-2 { right: -7%; top: -3%; transform: rotate(5deg); }
.s3db-end-tile-3 { left: 1%; top: 28%; transform: rotate(4deg); }
.s3db-end-tile-4 { right: 0%; top: 30%; transform: rotate(-5deg); }
.s3db-end-tile-5 { left: -5%; bottom: -7%; transform: rotate(6deg); }
.s3db-end-tile-6 { right: -6%; bottom: -6%; transform: rotate(-4deg); }

.s3db-end-wash {
    background:
        radial-gradient(circle at 50% 49%, rgba(255,255,255,.82) 0 22%, rgba(255,255,255,.64) 42%, rgba(255,255,255,.48) 72%),
        rgba(255,255,255,.24);
    backdrop-filter: blur(.4px);
}

.s3db-end-cue {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: rgba(45,42,38,.78);
    text-align: center;
    transform: translateY(-1%);
}

.s3db-end-book {
    display: block;
    width: clamp(48px, 8vw, 84px);
    margin-bottom: 18px;
    color: #a88336;
}

.s3db-end-book svg {
    display: block;
    width: 100%;
    height: auto;
    fill: rgba(255,255,255,.13);
    stroke: currentColor;
    stroke-width: 2.6;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.s3db-end-label {
    display: block;
    font-weight: 400;
    text-transform: uppercase;
    line-height: 1.25;
}

.s3db-end-label-bg {
    font-size: clamp(15px, 2.1vw, 24px);
    letter-spacing: .24em;
    padding-left: .24em;
}

.s3db-end-label-en {
    margin-top: 5px;
    font-size: clamp(13px, 1.7vw, 20px);
    letter-spacing: .30em;
    padding-left: .30em;
    opacity: .88;
}

.s3db-end-rule {
    position: relative;
    display: block;
    width: 118px;
    height: 1px;
    margin-top: 19px;
    background: rgba(168,131,54,.46);
}

.s3db-end-rule i {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: #a88336;
    transform: translate(-50%,-50%);
    box-shadow: 0 0 0 5px rgba(255,255,255,.68);
}

/* v1.4.4 — a centered single cover still lives inside PageFlip's two-page
   landscape canvas. Remove the canvas-level shadow while that phantom half
   is hidden, so no stray shadow appears beside the centered cover. */
.s3db-book-positioner.s3db-cover-first .s3db-book-container,
.s3db-book-positioner.s3db-cover-last .s3db-book-container {
    box-shadow: none;
}