/* Main Product Section */
.product-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    margin-bottom: 60px;
    align-items: center;
    margin-top: 150px;
}

/* 3D Book Container */
.book-container {
    perspective: 1000px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
    position: relative;
}

.book-3d {
    width: 350px;
    height: 480px;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s ease;
    cursor: pointer;
}

.book-3d:hover {
    transform: rotateY(-15deg) rotateX(5deg);
}

.book-cover {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(145deg, #4a90e2, #357abd);
    border-radius: 8px;
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.3),
        inset 0 2px 10px rgba(255, 255, 255, 0.2);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    text-align: center;
    padding: 40px 30px;
    transform: translateZ(15px);
}

/*.book-spine {*/
/*    position: absolute;*/
/*    width: 30px;*/
/*    height: 100%;*/
/*    background: linear-gradient(145deg, #357abd, #2968a3);*/
/*    right: -15px;*/
/*    top: 0;*/
/*    transform: rotateY(90deg);*/
/*    transform-origin: left;*/
/*    border-radius: 0 8px 8px 0;*/
/*    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.3);*/
/*}*/

.book-title-3d {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.book-subtitle-3d {
    font-size: 16px;
    opacity: 0.9;
    margin-bottom: 30px;
}

.book-author-3d {
    font-size: 18px;
    font-weight: 600;
    margin-top: auto;
}

/* PDF Viewer Modal */
.pdf-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.pdf-viewer {
    background: white;
    border-radius: 15px;
    padding: 20px;
    max-width: 90%;
    max-height: 90%;
    position: relative;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.close-btn {
    position: absolute;
    top: 15px;
    right: 20px;
    background: #ff6b6b;
    color: white;
    border: none;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 18px;
    font-weight: bold;
}

.book-pages {
    display: flex;
    gap: 20px;
    max-width: 800px;
    max-height: 600px;
}

.page {
    background: #fefefe;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 30px;
    width: 350px;
    height: 500px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    overflow-y: auto;
    font-size: 14px;
    line-height: 1.8;
    transition: transform 0.3s ease;
}

.page:hover {
    transform: translateY(-5px);
}

.page-controls {
    text-align: center;
    margin-top: 20px;
}

.page-btn {
    background: #4a90e2;
    color: white;
    border: none;
    padding: 10px 20px;
    margin: 0 10px;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.page-btn:hover {
    background: #357abd;
    transform: translateY(-2px);
}

.page-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

/* Product Details */
.product-details {
    padding: 20px 0;
}

.product-title {
    font-size: 42px;
    font-weight: 800;
    color: #2c3e50;
    margin-bottom: 15px;
    line-height: 1.2;
}

.product-author {
    font-size: 20px;
    color: #6c7b8a;
    margin-bottom: 20px;
}

.rating {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 25px;
}

.stars {
    display: flex;
    gap: 2px;
}

.star {
    color: #ffd700;
    font-size: 20px;
}

.rating-text {
    color: #6c7b8a;
    font-size: 14px;
}

.price {
    font-size: 36px;
    font-weight: 700;
    color: #ed252c;
    margin-bottom: 20px;
}

.original-price {
    text-decoration: line-through;
    color: #2c3e50;
    font-size: 24px;
    margin-left: 15px;
}

.description {
    font-size: 16px;
    color: #5a6c7d;
    margin-bottom: 35px;
    line-height: 1.7;
}

.buy-btn {
    background: #ed252c;
    color: white;
    border: none;
    padding: 18px 40px;
    font-size: 18px;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 8px 25px rgba(74, 144, 226, 0.3);
    margin-bottom: 20px;
    width: 100%;
    margin-right: 10px;
}

.buy-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(74, 144, 226, 0.4);
}

.preview-btn {
    background: #073050;
    color: white;
    padding: 18px 40px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    margin-bottom: 20px;
}

.preview-btn:hover {
    background: #073050;
    color: white;
    transform: translateY(-2px);
}

.features {
    display: flex;
    gap: 20px;
    margin-top: 30px;
}

.feature {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #6c7b8a;
    font-size: 14px;
}

.feature-icon {
    color: #4a90e2;
    font-size: 16px;
}

/* What's Inside Section */
.whats-inside {
    background: rgba(255, 255, 255, 0.85);
    padding: 50px 20px;
    border-radius: 25px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.5);
    margin: 0 auto 60px auto;
}

.chapters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.chapter-card {
    background: #f0f7ff;
    border-radius: 20px;
    padding: 30px 25px;
    box-shadow: 0 8px 25px rgba(74, 144, 226, 0.15);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: default;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.chapter-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(74, 144, 226, 0.3);
}

.chapter-icon {
    font-size: 48px;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #073050, #ed222a);
    color: white;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

.chapter-title {
    font-size: 22px;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 12px;
}

.chapter-desc {
    font-size: 15px;
    color: #5a6c7d;
    line-height: 1.6;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .chapters-grid {
        grid-template-columns: 1fr;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .product-section {
        grid-template-columns: 1fr;
        gap: 30px;
        text-align: center;
    }

    .product-title {
        font-size: 32px;
    }

    .book-3d {
        width: 280px;
        height: 380px;
    }

    .book-title-3d {
        font-size: 22px;
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        left: 0 !important;
        padding-left: 60px !important;
        padding-right: 20px !important;
        text-align: left !important;
    }

    .timeline-item .timeline-content::after {
        left: -10px !important;
        border: 10px solid transparent !important;
        border-right-color: white !important;
    }

    .timeline-dot {
        left: 20px;
        transform: none;
    }

    .nav-links {
        display: none;
    }

    .book-pages {
        flex-direction: column;
        max-height: 70vh;
        overflow-y: auto;
    }

    .page {
        width: 100%;
        max-width: 400px;
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.timeline-item {
    animation: fadeInUp 0.6s ease forwards;
}

.review-card {
    animation: fadeInUp 0.6s ease forwards;
}

/* Sample PDF Content */
.sample-content {
    line-height: 1.8;
}

.sample-content h3 {
    color: #2c3e50;
    margin-bottom: 15px;
    font-size: 18px;
}

.sample-content p {
    margin-bottom: 15px;
    text-align: justify;
}

.sample-content .highlight {
    background: #fff3cd;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 600;
}