.flipbook-outer {
    width: 100%;
    margin: 2rem auto;
    text-align: center;
}

.flipbook {
    width: 100%;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: visible;
    touch-action: pan-y;
}

.flipbook-wrapper {
    position: relative;
    width: 100%;
    max-width: 1100px;
    margin: 2rem auto;
    background: white;
    box-shadow: 0 10px 30px rgba(0, 0, 0, .15);
}

.flipbook-wrapper.is-single-page {
    max-width: 550px;
}

.flipbook-wrapper.is-cover-spread {
    max-width: 1100px;
}

.flipbook-canvas {
    width: 100%;
    height: auto;
    display: block;
}

.flipbook-canvas-base {
    position: relative;
    z-index: 1;
    will-change: transform, opacity;
}

.flipbook-transition-canvas {
    position: absolute;
    inset: 0;
    z-index: 2;
    opacity: 0;
    transform: translate3d(0, 0, 0);
    pointer-events: none;
    will-change: transform, opacity, filter;
    box-shadow: none;
}

/* Übergangscanvas wird für Fade und Slide verwendet. */

.flipbook-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 60px;
    height: 60px;
    padding: 0;
    border: none;
    border-radius: 50%;
    background: rgba(0, 0, 0, .45);
    color: white;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    transition: background .2s ease, transform .2s ease, opacity .2s ease;
    z-index: 20;
}

.flipbook-prev { left: 2rem; }
.flipbook-next { right: 2rem; }

.flipbook-arrow:hover:not(:disabled) {
    background: rgba(0, 0, 0, .65);
    transform: translateY(-50%) scale(1.05);
}

.flipbook-arrow:disabled {
    opacity: .6;
    cursor: default;
}

@media (max-width: 991px) {
    .flipbook-wrapper,
    .flipbook-wrapper.is-single-page,
    .flipbook-wrapper.is-cover-spread {
        max-width: calc(100vw - 1rem);
    }

    .flipbook-arrow {
        width: 40px;
        height: 40px;
        font-size: 1.25rem;
    }

    .flipbook-prev { left: .25rem; }
    .flipbook-next { right: .25rem; }
}

@media (max-width: 768px) {
    .flipbook-arrow {
        width: 35px;
        height: 35px;
        font-size: 1.25rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .flipbook-fade-canvas {
        transition-duration: .01ms;
        filter: none;
        transform: none;
    }

    .flipbook-arrow {
        transition: none;
    }
}

/* Stabiler, weicher Größenwechsel zwischen Cover und Doppelseite. */
.flipbook-wrapper {
    overflow: hidden;
    transition: width .65s cubic-bezier(.22,.61,.36,1),
                height .65s cubic-bezier(.22,.61,.36,1),
                box-shadow .45s ease;
}

.flipbook-wrapper .flipbook-canvas {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}