@font-face {
    font-family: 'KeplerStd';
    src: url('../fonts/KeplerStd-BoldScnDisp.otf') format('opentype');
    font-weight: bold;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'KeplerStd';
    src: url('../fonts/KeplerStd-BoldScnItDisp.otf') format('opentype');
    font-weight: bold;
    font-style: italic;
    font-display: swap;
}

@font-face {
    font-family: 'KeplerStd-Cn';
    src: url('../fonts/KeplerStd-CnDisp.otf') format('opentype');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'KeplerStd-BoldIt';
    src: url('../fonts/KeplerStd-BoldScnItDisp.otf') format('opentype');
    font-weight: bold;
    font-style: italic;
    font-display: swap;
}

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

.zbook-slider-wrapper {
    position: relative;
    padding: 0 35px;
    max-width: 100%;
    overflow: visible;
}

.zbook-slider-wrapper .swiper {
    width: 100%;
    padding: 10px 0 40px 0;
    overflow: hidden;
}

.zbook-slider-wrapper .swiper-wrapper {
    margin: 0;
    padding: 0;
}

.zbook-slider-wrapper .swiper-slide {
    display: flex;
    justify-content: center;
    align-items: flex-end;
    overflow: visible;
    padding-bottom: 25px;
}

/* Perspective stage — like the reference ".perspective" */
.zbook-slider-wrapper .book-card {
    position: relative;
    width: 100%;
    max-width: 350px;
    aspect-ratio: 280 / 420;
    cursor: pointer;
    perspective: 1600px;
    perspective-origin: center center;
    flex-shrink: 0;
    --book-corner: 0px;
    --book-thickness: 38px;
    --book-tilt: 20deg;
    border-radius: var(--book-corner);
}

/* The 3D book object — like the reference ".book-wrap" */
.zbook-slider-wrapper .book-inner {
    position: absolute;
    inset: 0;
    transform-style: preserve-3d;
    -webkit-transform-style: preserve-3d;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
}

/* Hover → whole book tilts to reveal the spine (reference ".rotate") */
@media (hover: hover) {
    .zbook-slider-wrapper .book-card:hover .book-inner {
        transform: rotateY(var(--book-tilt));
    }
}

/* Click → book flips open to reveal the back content (reference ".flip") */
.zbook-slider-wrapper .book-card.is-open .book-inner {
    transform: rotateY(180deg);
}

/* "Hover Animation" OFF → block the click-to-flip (hover tilt + spine still work) */
.zbook-slider-wrapper .book-card[data-hover="no"].is-open .book-inner {
    transform: none;
}

/* Cover — front face (reference ".book") */
.zbook-slider-wrapper .book-front {
    position: absolute;
    inset: 0;
    z-index: 3;
    background: #fff;
    border-radius: var(--book-corner);
    overflow: hidden;
    clip-path: inset(0 round var(--book-corner));
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    transform: translateZ(0.1px);
}

.zbook-slider-wrapper .book-front img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: var(--book-corner);
    clip-path: inset(0 round var(--book-corner));
    display: block;
}

.zbook-slider-wrapper .book-front-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #e0e0e0 0%, #f5f5f5 100%);
    border-radius: var(--book-corner);
    display: flex;
    align-items: center;
    justify-content: center;
}

.zbook-slider-wrapper .book-front-placeholder::after {
    content: "Book";
    color: #999;
    font-size: 24px;
    font-style: italic;
}

/* Spine / binding — the book's left thickness edge (reference ".title") */
.zbook-slider-wrapper .book-spine {
    position: absolute;
    top: 0;
    left: 0;
    width: var(--book-thickness);
    height: 100%;
    z-index: 2;
    transform-origin: left center;
    transform: rotateY(90deg);
    background: var(--spine-bg, #6b7a5e);
    box-shadow: inset -2px 0 4px rgba(0, 0, 0, 0.18);
}

.zbook-slider-wrapper .book-spine.red {
    --spine-bg: #c25a52;
}

.zbook-slider-wrapper .book-spine.olive {
    --spine-bg: #74856a;
}

.zbook-slider-wrapper .book-spine.navy {
    --spine-bg: #46607f;
}

/* Back content — the back face (reference ".book-back") */
.zbook-slider-wrapper .book-back {
    position: absolute;
    inset: 0;
    border-radius: var(--book-corner);
    overflow: hidden;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    transform: translateZ(calc(var(--book-thickness) * -1)) rotateY(180deg);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.zbook-slider-wrapper .book-card.is-open .book-back {
    opacity: 1;
    transition-delay: 0.25s;
}

.zbook-slider-wrapper .book-card.is-open {
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2), 0 8px 25px rgba(0, 0, 0, 0.1);
    transition: box-shadow 0.4s ease 0.25s;
}

.zbook-slider-wrapper .book-header {
    position: relative;
    height: 120px;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    flex-shrink: 0;
}

.zbook-slider-wrapper .book-header.red {
    background: #aa1917;
}

.zbook-slider-wrapper .book-header.olive {
    background: #4a5741;
}

.zbook-slider-wrapper .book-header.navy {
    background: #1e2d3d;
}

.zbook-slider-wrapper .book-header .title {
    color: #fff;
    font-family: 'KeplerStd-Cn', 'KeplerStd', Georgia, serif;
    font-size: 1.5rem;
    letter-spacing: 2px;
    font-weight: bold;
    text-transform: uppercase;
    text-align: center;
    line-height: 1.5;
    width: 100%;
    margin: 0;
    padding: 10px 20px 0 20px;
}


.zbook-slider-wrapper .book-info {
    flex: 1;
    background: #fff;
    padding: 15px 25px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.zbook-slider-wrapper .book-info h3 {
    color: #333;
    font-family: 'KeplerStd-BoldIt', 'KeplerStd', Georgia, serif;
    font-size: 2rem;
    letter-spacing: 1px;
    line-height: 1;
    font-style: italic;
    font-weight: 400;
    margin-bottom: 10px;
    text-align: center;
    word-wrap: break-word;
    overflow-wrap: break-word;
    hyphens: auto;
    max-width: 100%;
}

.zbook-slider-wrapper .book-info p {
    color: #666;
    font-size: 1rem;
    line-height: 1.5;
    text-align: center;
    margin-bottom: 12px;
    word-wrap: break-word;
    overflow-wrap: break-word;
    hyphens: auto;
    max-width: 100%;
}

.zbook-slider-wrapper .book-info .cta-link {
    display: inline-block;
    min-height: 44px;
    padding: 10px 12px;
    font-size: 1rem;
    line-height: 1.4;
    color: #333;
    background: none;
    border: none;
    text-decoration: underline;
    cursor: pointer;
}

.zbook-slider-wrapper .book-info .cta-link:hover {
    color: #aa1917;
}

@media (prefers-reduced-motion: reduce) {
    .zbook-slider-wrapper .book-inner {
        transition-duration: 0.01ms !important;
    }
}

.zbook-slider-wrapper .swiper-button-next,
.zbook-slider-wrapper .swiper-button-prev {
    color: #999 !important;
    width: auto;
    height: auto;
}

.zbook-slider-wrapper .swiper-button-next {
    right: -10px !important;
}

.zbook-slider-wrapper .swiper-button-prev {
    left: -10px !important;
}

.zbook-slider-wrapper .swiper-button-next:hover,
.zbook-slider-wrapper .swiper-button-prev:hover {
    color: #3d4a35 !important;
}

.zbook-slider-wrapper .swiper-button-next::after,
.zbook-slider-wrapper .swiper-button-prev::after {
    font-size: 32px !important;
    font-weight: 700 !important;
}

@media (max-width: 768px) {
    .zbook-slider-wrapper {
    padding: 0 20px;
    }

    .zbook-slider-wrapper .swiper-button-next {
    right: -6px !important;
    }

    .zbook-slider-wrapper .swiper-button-prev {
    left: -6px !important;
    }

.zbook-slider-wrapper .swiper-button-next::after,
.zbook-slider-wrapper .swiper-button-prev::after {
    font-size: 22px !important;
    font-weight: 900 !important;
}

    .zbook-slider-wrapper .book-card {
        --book-thickness: 28px;
        --book-tilt: 18deg;
        --book-corner: 0px;
        width: 300px;
        max-width: 100%;
    }

    .zbook-slider-wrapper .book-header {
        height: 100px;
    }

    .zbook-slider-wrapper .book-header .title {
        font-size: 0.85rem;
    }

    .zbook-slider-wrapper .book-info {
        padding: 14px 18px;
    }

    .zbook-slider-wrapper .book-info h3 {
        font-size: 1.3rem;
        letter-spacing: 0.8px;
        margin-bottom: 8px;
    }

    .zbook-slider-wrapper .book-info p {
        font-size: 0.85rem;
        margin-bottom: 10px;
    }
}

/* ============================================================
   Mobile tap hint — pulse circle (bottom-right)
   ============================================================ */
@media (max-width: 767px) {
    .zbook-slider-wrapper .book-tap-hint {
        display: none;
        position: absolute;
        left: 15px;
        top: 15px;
        width: 50px;
        height: 50px;
        background-color: var(--main-bg-color, #ffffff);
        background-image: url("../images/tap.png");
        background-repeat: no-repeat;
        background-position: center;
        background-size: 26px;
        border-radius: 50%;
        align-items: center;
        justify-content: center;
        z-index: 10;
        transition: all 0.3s ease;
        pointer-events: none; /* tap goes THROUGH button to the book */
    }

    .zbook-slider-wrapper .book-tap-hint i {
        display: none;
    }

    @keyframes zbook-tap-pulse {
        0% {
            transform: scale(0.95);
            box-shadow: 0 0 0 0 var(--main-bg-color, #ffffff);
        }
        70% {
            transform: scale(1.05);
            box-shadow: 0 0 0 15px rgba(255, 255, 255, 0);
        }
        100% {
            transform: scale(0.95);
            box-shadow: 0 0 0 0 rgba(255, 255, 255, 0);
        }
    }

    /* Show the pulse only for tappable books on touch devices */
    @media (hover: none) {
        .zbook-slider-wrapper .book-card:not([data-hover="no"]) .book-tap-hint {
            display: flex;
            animation: zbook-tap-pulse 2s infinite;
        }

        /* Hide once the book is open */
        .zbook-slider-wrapper .book-card.is-open .book-tap-hint {
            opacity: 0;
            visibility: hidden;
            animation: none;
        }
    }

    /* Permanently hide after the user has tapped once (persisted via localStorage) */
    .zbook-slider-wrapper.tap-seen .book-tap-hint {
        display: none !important;
    }
}