:root {
            --primary: #6a5acd;      /* Slate blue */
            --secondary: #ff69b4;    /* Hot pink */
            --accent: #ff1493;       /* Deep pink */
            --light-blue: #e6f0ff;   /* Very light blue */
            --light-pink: #fff0f5;   /* Lavender blush */
            --dark: #4b0082;         /* Indigo */
            --text: #333333;
            --light: #f8f9fa;
        }
        
        body {
 
            color: var(--text);
            background-color: #fefefe;
        }
        
        .navbar {
            background: linear-gradient(135deg, var(--primary) 0%, var(--dark) 100%);
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        
        .navbar-brand {
            font-weight: 700;
            font-size: 1.8rem;
            color: white !important;
        }
        
        .nav-link {
            color: rgba(255,255,255,0.85) !important;
            font-weight: 500;
        }
        
        .nav-link:hover, .nav-link.active {
            color: white !important;
        }
        
        .breadcrumb {
            background-color: var(--light-blue);
            border-radius: 10px;
            padding: 12px 20px;
        }
        
        .breadcrumb-item a {
            color: var(--primary);
            text-decoration: none;
        }
        
        .breadcrumb-item.active {
            color: var(--dark);
            font-weight: 500;
        }
        
        .product-image {
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            width: 100%;
            max-width: 400px;
        }
        
        .thumbnail-container {
            display: flex;
            gap: 10px;
            margin-top: 15px;
        }
        
        .thumbnail {
            width: 70px;
            height: 90px;
            object-fit: cover;
            border-radius: 8px;
            cursor: pointer;
            border: 2px solid transparent;
            transition: all 0.3s;
        }
        
        .thumbnail:hover, .thumbnail.active {
            border-color: var(--primary);
        }
        
        .product-title {
            font-weight: 700;
            color: var(--dark);
            margin-bottom: 10px;
        }
        
        .product-author {
            font-size: 1.2rem;
            color: #666;
            margin-bottom: 15px;
        }
        
        .rating {
            color: #ffc107;
            margin-bottom: 15px;
        }
        
        .rating-count {
            color: #666;
            margin-left: 10px;
        }
        
        .price {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--accent);
            margin-bottom: 5px;
        }
        
        .old-price {
            text-decoration: line-through;
            color: #999;
            font-size: 1.2rem;
            margin-left: 10px;
        }
        
        .discount-badge {
            background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
            color: white;
            padding: 5px 12px;
            border-radius: 20px;
            font-weight: 600;
            font-size: 0.9rem;
            display: inline-block;
            margin-left: 10px;
        }
        
        .product-meta {
            margin: 20px 0;
            padding: 15px;
            background-color: var(--light-blue);
            border-radius: 10px;
        }
        
        .meta-item {
            display: flex;
            margin-bottom: 10px;
        }
        
        .meta-label {
            font-weight: 600;
            min-width: 120px;
            color: var(--dark);
        }
        
        .stock-status {
            color: #28a745;
            font-weight: 600;
        }
        
        .btn-primary {
            background: linear-gradient(135deg, var(--primary) 0%, var(--dark) 100%);
            border: none;
            border-radius: 30px;
            padding: 12px 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(106, 90, 205, 0.4);
        }
        
        .btn-secondary {
            background: linear-gradient(135deg, var(--secondary) 0%, var(--accent) 100%);
            border: none;
            border-radius: 30px;
            padding: 12px 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        
        .btn-secondary:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(255, 105, 180, 0.4);
        }
        
        .btn-outline-primary {
            border: 2px solid var(--primary);
            color: var(--primary);
            border-radius: 30px;
            font-weight: 600;
            transition: all 0.3s;
        }
        
        .btn-outline-primary:hover {
            background: var(--primary);
            color: white;
        }
        
        .quantity-selector {
            display: flex;
            align-items: center;
            margin: 20px 0;
        }
        
        .quantity-btn {
            width: 40px;
            height: 40px;
            border: 1px solid #ddd;
            background: white;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            font-size: 1.2rem;
        }
        
        .quantity-input {
            width: 60px;
            height: 40px;
            border: 1px solid #ddd;
            border-left: none;
            border-right: none;
            text-align: center;
            font-weight: 600;
        }
        
        .action-buttons {
            display: flex;
            gap: 15px;
            margin: 25px 0;
        }
        
        .wishlist-btn {
            width: 50px;
            height: 50px;
            border: 2px solid #ddd;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.3s;
            color: #666;
        }
        
        .wishlist-btn:hover, .wishlist-btn.active {
            border-color: var(--accent);
            color: var(--accent);
            background-color: rgba(255, 20, 147, 0.1);
        }
        
        .delivery-info {
            background-color: var(--light-pink);
            border-radius: 10px;
            padding: 20px;
            margin: 25px 0;
        }
        
        .delivery-item {
            display: flex;
            align-items: center;
            margin-bottom: 15px;
        }
        
        .delivery-icon {
            width: 40px;
            height: 40px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 15px;
        }
        
        .section-title {
            position: relative;
            margin: 40px 0 25px;
            font-weight: 700;
            color: var(--dark);
            padding-bottom: 10px;
        }
        
        .section-title:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 3px;
            background: linear-gradient(to right, var(--primary), var(--secondary));
            border-radius: 2px;
        }
        
        .tab-content {
            padding: 25px 0;
        }
        
        .nav-tabs .nav-link {
            color: var(--dark);
            font-weight: 600;
            border: none;
            padding: 12px 25px;
        }
        
        .nav-tabs .nav-link.active {
            color: var(--primary);
            border-bottom: 3px solid var(--primary);
            background: transparent;
        }
        
        .review-card {
            border: none;
            border-radius: 12px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            margin-bottom: 25px;
            padding: 20px;
        }
        
        .review-header {
            display: flex;
            justify-content: space-between;
            margin-bottom: 15px;
        }
        
        .reviewer-name {
            font-weight: 600;
            color: var(--dark);
        }
        
        .review-date {
            color: #999;
            font-size: 0.9rem;
        }
        
        .review-title {
            font-weight: 600;
            margin-bottom: 10px;
        }
        
        .review-helpful {
            display: flex;
            align-items: center;
            margin-top: 15px;
            color: #666;
        }
        
        .helpful-btn {
            background: none;
            border: 1px solid #ddd;
            border-radius: 20px;
            padding: 5px 15px;
            margin-right: 10px;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .helpful-btn:hover {
            background: var(--light-blue);
            border-color: var(--primary);
        }
        
        .review-form {
            background-color: var(--light-blue);
            border-radius: 12px;
            padding: 25px;
            margin-top: 30px;
        }
        
        .related-products {
            margin: 50px 0;
        }
        
        .book-card {
            transition: transform 0.3s, box-shadow 0.3s;
            border: none;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            height: 100%;
            border-radius: 12px;
            overflow: hidden;
            background: white;
            margin-bottom: 25px;
        }
        
        .book-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(106, 90, 205, 0.2);
        }
        
        .book-cover {
            height: 200px;
            object-fit: cover;
            width: 100%;
        }
        
        .footer {
            background: linear-gradient(135deg, var(--primary) 0%, var(--dark) 100%);
            color: white;
            padding: 60px 0 30px;
            margin-top: 50px;
        }
        
        .social-links a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            transition: all 0.3s;
        }
        
        .social-links a:hover {
            background: var(--secondary);
            transform: translateY(-3px);
        }
        
        @media (max-width: 768px) {
            .action-buttons {
                flex-direction: column;
            }
            
            .action-buttons .btn {
                width: 100%;
            }
        }