#book {
    max-width: 600px;
    margin: auto;
    position: relative;
}

.page {
    display: none;
    animation: flip 0.6s ease;
}

    .page.active {
        display: block;
    }

    .page img {
        max-width: 100%;
        margin-top: 10px;
    }

@keyframes flip {
    from {
        transform: rotateY(90deg);
        opacity: 0;
    }

    to {
        transform: rotateY(0);
        opacity: 1;
    }
}

.page-number {
    display: block;
    margin-top: 12px;
    font-size: 0.9em;
    color: gray;
    text-align: center;
}

/* Landing page */
.landing {
    text-align: center;
    padding: 40px;
}

.read-btn {
    display: inline-block;
    padding: 15px 30px;
    background: black;
    color: white;
    text-decoration: none;
    border-radius: 8px;
}
.page-nav {
    display: flex;
    justify-content: center;
    margin: 20px 0;
    gap: 20px;
}

.nav-btn {
    padding: 10px 20px;
    background-color: black;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
}

    .nav-btn:disabled {
        background-color: gray;
        cursor: not-allowed;
    }
.page-indicator {
    text-align: center;
    font-size: 1.1em;
    margin: 10px 0;
    color: #333;
}