:root {
            --primary: #4361ee;
            --secondary: #3a0ca3;
            --accent: #f72585;
            --light: #f8f9fa;
            --dark: #212529;
            --success: #4cc9f0;
            --warning: #ffd166;
            --danger: #ef476f;
            --gray: #6c757d;
            --light-gray: #e9ecef;
            --card-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
            --hover-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
            --transition: all 0.3s ease;
        }

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

        body {
            font-family: 'Poppins', sans-serif;
            background: linear-gradient(135deg, #f5f7fa 0%, #e4e9f2 100%);
            color: rgb(6, 136, 211);
            line-height: 1;
            padding-bottom: 2rem;
            font-weight: 700;
        }

        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 1rem;
        }

        /* Page Header */
        .page-header {
            padding: 15px 0;
            background: linear-gradient(135deg, #4361ee 0%, #3a0ca3 100%);
            color: white;
            border-radius: 0 0 30px 30px;
            margin-bottom: 30px;
            text-align: center;
        }

        .page-header h1 {
            font-size: 2rem;
            margin-bottom: 15px;
            color: #e4e9f2;
        }
        .page-header a {
            color: #ffd166;
            text-decoration: none;
        }

        /* Modern Tabs */
        .tabs-container {
            margin: 0 auto 30px;
            max-width: 1200px;
        }

        .tabs {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 10px;
            margin-bottom: 30px;
        }

        .tab {
            padding: 16px 32px;
            background: rgba(19, 150, 211, 0.897);
            backdrop-filter: blur(10px);
            border-radius: 50px;
            cursor: pointer;
            font-weight: 600;
            font-size: 1.1rem;
            transition: var(--transition);
            border: 2px solid transparent;
            color: white;
            position: relative;
            overflow: hidden;
        }

        .tab::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
            transition: var(--transition);
        }

        .tab:hover::before {
            left: 100%;
        }

        .tab:hover {
            background: rgba(4, 155, 224, 0.521);
            transform: translateY(-2px);
        }

        .tab.active {
            background: rgba(8, 221, 54, 0.932);
            color: rgb(232, 236, 9);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            border-color: rgba(255, 255, 255, 0.5);
        }

        .tab-content {
            display: none;
            animation: fadeIn 0.5s ease;
        }

        .tab-content.active {
            display: block;
        }

        .section {
            margin: 3rem 0;
            animation: fadeIn 0.8s ease-out;
        }

        .section h2 {
            font-family: 'Roboto Slab', serif;
            text-align: center;
            margin-bottom: 2.5rem;
            color: var(--secondary);
            font-size: 2.2rem;
            position: relative;
            padding-bottom: 0.5rem;
        }

        .section h2::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 100px;
            height: 4px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            border-radius: 2px;
        }

        .products-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 2rem;
        }

        .product-card {
            background: white;
            border-radius: 16px;
            overflow: hidden;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.05);
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
            display: flex;
            flex-direction: column;
            height: 100%;
            position: relative;
        }

        .product-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
        }

        .image-container {
            position: relative;
            overflow: hidden;
            height: 300px;
        }

        .product-image {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: var(--transition);
        }

        .product-card:hover .product-image {
            transform: scale(1.25);
        }

        .product-badge {
            position: absolute;
            top: 15px;
            right: 15px;
            background: #6c5ce7;
            color: rgb(31, 240, 4);
            padding: 5px 12px;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
            box-shadow: 0 4px 10px rgba(108, 92, 231, 0.3);
            z-index: 2;
        }

        .product-info {
            padding: 1.5rem;
            display: flex;
            flex-direction: column;
            flex-grow: 1;
        }

        .product-title {
            font-family: 'Roboto Slab', serif;
            margin-bottom: 1rem;
            font-size: 1.3rem;
            color: var(--secondary);
        }

        .product-title a {
            color: inherit;
            text-decoration: none;
            transition: var(--transition);
            display: flex;
            align-items: center;
        }

        .product-title a:hover {
            color: var(--primary);
        }

        .product-icon {
            margin-right: 0.5rem;
            color: var(--primary);
        }

        .book-view {
            font-size: 0.8rem;
            color: var(--gray);
            font-weight: normal;
            margin-left: 0.3rem;
        }

        .product-description {
            margin-bottom: 1.5rem;
            flex-grow: 1;
        }

        .book_term {
            list-style: none;
            padding: 0;
        }

        .book_term li {
            padding: 0.3rem 0;
            position: relative;
            padding-left: 1.5rem;
        }

        .book_term li::before {
            content: '•';
            color: var(--primary);
            font-weight: bold;
            position: absolute;
            left: 0;
        }
        .product-meta {
            display: flex;
            align-items: center;
            border-top: 1px solid #e9ecef;
            padding-top: 18px;
            margin-top: auto;
            
        }
        .product-meta a {
            text-decoration: none;
        }

        .action-button {
            width: 100%;
            padding: 0.8rem 1.2rem;
            background: linear-gradient(90deg, var(--primary), var(--secondary));
            color: white;
            border: none;
            border-radius: 18px;
            font-weight: 500;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            justify-content: space-between;
            align-items: center;
            box-shadow: 0 4px 10px rgba(67, 97, 238, 0.3);
        }

        .action-button:hover {
            background: linear-gradient(90deg, var(--secondary), var(--primary));
            transform: translateY(-2px);
            box-shadow: 0 6px 15px rgba(67, 97, 238, 0.4);
        }

        /* Animations */
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .product-card {
            animation: fadeInUp 0.6s ease-out;
        }

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

        /* Responsive Design */
        @media (max-width: 1200px) {
            .products-grid {
                grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            }
        }

        @media (max-width: 992px) {
            .section h2 {
                font-size: 1.9rem;
            }
            
            .tab {
                padding: 14px 28px;
                font-size: 1rem;
            }
        }

        @media (max-width: 768px) {
            .products-grid {
                grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
                gap: 1.5rem;
            }
            
            .section h2 {
                font-size: 1.7rem;
                margin-bottom: 2rem;
            }
            
            .product-info {
                padding: 1.2rem;
            }
            
            .tabs {
                gap: 8px;
            }
            
            .tab {
                padding: 12px 24px;
                font-size: 0.95rem;
            }
        }

        @media (max-width: 576px) {
            .products-grid {
                grid-template-columns: 1fr;
                max-width: 400px;
                margin: 0 auto;
            }
            
            .section h2 {
                font-size: 1.5rem;
            }
            
            .image-container {
                height: 200px;
            }
            
            body {
                padding: 0 0.5rem 1rem;
            }
            
            .tabs {
                flex-direction: column;
                align-items: center;
            }
            
            .tab {
                width: 100%;
                max-width: 280px;
                text-align: center;
                margin-bottom: 8px;
            }
            
            .page-header h1 {
                font-size: 2.2rem;
            }
        }

        /* Stagger animation for cards */
        .products-grid .product-card:nth-child(1) { animation-delay: 0.1s; }
        .products-grid .product-card:nth-child(2) { animation-delay: 0.2s; }
        .products-grid .product-card:nth-child(3) { animation-delay: 0.3s; }
        .products-grid .product-card:nth-child(4) { animation-delay: 0.4s; }
        .products-grid .product-card:nth-child(5) { animation-delay: 0.5s; }
        .products-grid .product-card:nth-child(6) { animation-delay: 0.6s; }
        .products-grid .product-card:nth-child(7) { animation-delay: 0.7s; }
        .products-grid .product-card:nth-child(8) { animation-delay: 0.8s; }