:root {
            --primary: #4361ee;
            --primary-light: #e0e7ff;
            --secondary: #3f37c9;
            --accent: #4895ef;
            --success: #4cc9f0;
            --danger: #f72585;
            --warning: #f8961e;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --free: #2ecc71;
            --free-light: #d5f5e3;
            --premium: #f39c12;
            --premium-light: #fdebd0;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Poppins', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background-color: #f8fafc;
            color: #334155;
            overflow-x: hidden;
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 20px;
        }
        
        .hero-section {
            background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
            color: white;
            padding: 80px 20px;
            border-radius: 16px;
            margin-bottom: 40px;
            text-align: center;
            position: relative;
            overflow: hidden;
            box-shadow: 0 20px 25px -5px rgba(67, 97, 238, 0.1), 0 10px 10px -5px rgba(67, 97, 238, 0.04);
        }
        
        .hero-section::before {
            content: '';
            position: absolute;
            top: -50px;
            right: -50px;
            width: 200px;
            height: 200px;
            background: rgba(255,255,255,0.1);
            border-radius: 50%;
            animation: float 6s ease-in-out infinite;
        }
        
        .hero-section::after {
            content: '';
            position: absolute;
            bottom: -80px;
            left: -80px;
            width: 300px;
            height: 300px;
            background: rgba(255,255,255,0.05);
            border-radius: 50%;
            animation: float 8s ease-in-out infinite;
            animation-delay: 1s;
        }
        
        .hero-title {
            font-size: 3rem;
            margin-bottom: 15px;
            position: relative;
            z-index: 2;
            text-shadow: 0 2px 4px rgba(0,0,0,0.1);
            animation: fadeInDown 0.8s ease-out;
        }
        
        .hero-subtitle {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 30px;
            position: relative;
            z-index: 2;
            opacity: 0.9;
            animation: fadeInUp 0.8s ease-out 0.2s both;
        }
        
        /* Modern Filter Section */
        .filter-section {
            background: white;
            border-radius: 12px;
            padding: 20px;
            margin-bottom: 40px;
            box-shadow: 0 4px 6px rgba(0,0,0,0.05);
            animation: fadeIn 0.8s ease-out 0.4s both;
        }
        
        .filter-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 20px;
        }
        
        .filter-title {
            font-size: 1.3rem;
            color: var(--dark);
            font-weight: 600;
        }
        
        .filter-reset {
            color: var(--primary);
            font-weight: 500;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .filter-reset:hover {
            text-decoration: underline;
        }
        
        .filter-options {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
        }
        
        .filter-group {
            flex: 1;
            min-width: 200px;
        }
        
        .filter-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--dark);
        }
        
        .filter-select {
            width: 100%;
            padding: 12px 15px;
            border-radius: 8px;
            border: 1px solid #e2e8f0;
            background-color: white;
            font-size: 0.95rem;
            transition: all 0.3s ease;
            appearance: none;
            background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right 10px center;
            background-size: 1em;
        }
        
        .filter-select:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
        }
        
        .filter-tags {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            margin-top: 15px;
        }
        
        .filter-tag {
            padding: 6px 12px;
            background: var(--primary-light);
            color: var(--primary);
            border-radius: 20px;
            font-size: 0.85rem;
            display: flex;
            align-items: center;
            gap: 5px;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .filter-tag:hover {
            background: var(--primary);
            color: white;
        }
        
        .filter-tag i {
            font-size: 0.7rem;
        }
        
        .class-tabs {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 10px;
            margin-bottom: 30px;
            position: relative;
            z-index: 2;
            animation: fadeIn 0.8s ease-out 0.6s both;
        }
        
        .class-tab {
            padding: 10px 24px;
            background: rgba(255,255,255,0.15);
            border-radius: 30px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-weight: 500;
            position: relative;
            overflow: hidden;
        }
        
        .class-tab:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .class-tab:hover, .class-tab.active {
            background: white;
            color: var(--primary);
        }
        
        .class-tab.active::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 30px;
            height: 3px;
            background: var(--primary);
            border-radius: 3px 3px 0 0;
        }
        
        .packages-container {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
            gap: 25px;
        }
        
        .class-section {
            margin-bottom: 50px;
            opacity: 0;
            transform: translateY(20px);
            animation: fadeInUp 0.6s ease-out forwards;
        }
        
        .class-section.visible {
            opacity: 1;
            transform: translateY(0);
        }
        
        .class-header {
            display: flex;
            align-items: center;
            margin-bottom: 25px;
            padding-bottom: 15px;
            border-bottom: 2px solid var(--primary-light);
        }
        
        .class-icon {
            width: 50px;
            height: 50px;
            background: var(--primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 15px;
            font-size: 1.5rem;
            box-shadow: 0 4px 6px rgba(67, 97, 238, 0.2);
        }
        
        .class-title {
            font-size: 1.8rem;
            color: var(--dark);
            font-weight: 600;
        }
        
        .package-card {
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 6px rgba(0,0,0,0.05);
            overflow: hidden;
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.1);
            border: 1px solid #e2e8f0;
            display: flex;
            flex-direction: column;
            position: relative;
            opacity: 0;
            transform: translateY(20px);
        }
        
        .package-card.visible {
            opacity: 1;
            transform: translateY(0);
        }
        
        .package-card:hover {
            transform: translateY(-10px) scale(1.02);
            box-shadow: 0 15px 30px rgba(67, 97, 238, 0.15);
        }
        
        .package-badge {
            position: absolute;
            top: 15px;
            right: 15px;
            padding: 5px 15px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 0.8rem;
            z-index: 2;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            animation: pulse 2s infinite;
        }
        
        .free-badge {
            background: var(--free);
            color: white;
        }
        
        .popular-badge {
            background: var(--accent);
            color: white;
        }
        
        .package-image {
            height: 180px;
            overflow: hidden;
            position: relative;
        }
        
        .package-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        
        .package-card:hover .package-image img {
            transform: scale(1.1);
        }
        
        .package-image::after {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: linear-gradient(to bottom, rgba(0,0,0,0.1) 0%, rgba(0,0,0,0.4) 100%);
        }
        
        .package-content {
            padding: 20px;
            flex-grow: 1;
            display: flex;
            flex-direction: column;
        }
        
        .package-subjects {
            display: inline-block;
            background: rgba(67, 97, 238, 0.1);
            color: var(--primary);
            padding: 6px 14px;
            border-radius: 30px;
            font-size: 0.8rem;
            margin-bottom: 12px;
            font-weight: 600;
        }
        
        .package-title {
            font-size: 1.4rem;
            margin-bottom: 12px;
            color: var(--dark);
            font-weight: 700;
            line-height: 1.3;
        }
        
        .package-description {
            color: var(--gray);
            margin-bottom: 15px;
            line-height: 1.6;
            font-size: 0.95rem;
            text-align: justify;
        }
        
        .package-features {
            margin-bottom: 20px;
        }
        
        .feature-item {
            display: flex;
            align-items: center;
            margin-bottom: 8px;
            color: #555;
            font-size: 0.9rem;
        }
        
        .feature-item i {
            color: var(--accent);
            margin-right: 8px;
            font-size: 0.9rem;
        }
        
        .package-footer {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-top: auto;
            padding-top: 15px;
            border-top: 1px solid #eee;
        }
        
        .package-pricing {
            display: flex;
            flex-direction: column;
        }
        
        .price-original {
            font-size: 0.9rem;
            color: var(--gray);
            text-decoration: line-through;
        }
        
        .price-current {
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--accent);
        }
        
        .free-price {
            color: var(--free);
        }
        
        .package-meta {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .meta-item {
            display: flex;
            align-items: center;
            font-size: 0.9rem;
            color: var(--gray);
        }
        
        .meta-item i {
            margin-right: 5px;
            color: var(--primary);
        }
        
        /* Enhanced Access Button */
        .action-btn {
            padding: 12px 24px;
            border-radius: 8px;
            font-weight: 600;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.1);
            position: relative;
            overflow: hidden;
            border: none;
            cursor: pointer;
            text-align: center;
            width: 100%;
            margin-top: 10px;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }
        
        .action-btn::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: 0.5s;
        }
        
        .action-btn:hover::before {
            left: 100%;
        }
        
        .btn-primary {
            background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
            color: white;
        }
        
        .btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(67, 97, 238, 0.3);
        }
        
        .btn-outline {
            border: 2px solid var(--primary);
            color: var(--primary);
            background: white;
        }
        
        .btn-outline:hover {
            background: var(--primary);
            color: white;
        }
        
        .btn-free {
            background: linear-gradient(135deg, var(--free) 0%, #27ae60 100%);
            color: white;
        }
        
        .btn-free:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(46, 204, 113, 0.3);
        }
        
        .btn-premium {
            background: linear-gradient(135deg, var(--premium) 0%, #e67e22 100%);
            color: white;
        }
        
        .btn-premium:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(243, 156, 18, 0.3);
        }
        
        .pdf-count {
            position: absolute;
            bottom: 15px;
            left: 15px;
            background: rgba(0,0,0,0.7);
            color: white;
            padding: 5px 12px;
            border-radius: 30px;
            font-size: 0.8rem;
            z-index: 2;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        /* Animations */
        @keyframes float {
            0%, 100% {
                transform: translateY(0);
            }
            50% {
                transform: translateY(-20px);
            }
        }
        
        @keyframes pulse {
            0% {
                box-shadow: 0 0 0 0 rgba(46, 204, 113, 0.4);
            }
            70% {
                box-shadow: 0 0 0 10px rgba(46, 204, 113, 0);
            }
            100% {
                box-shadow: 0 0 0 0 rgba(46, 204, 113, 0);
            }
        }
        
        @keyframes fadeIn {
            from {
                opacity: 0;
            }
            to {
                opacity: 1;
            }
        }
        
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        @keyframes fadeInDown {
            from {
                opacity: 0;
                transform: translateY(-20px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        
        /* Responsive Design */
        @media (max-width: 992px) {
            .packages-container {
                grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            }
            
            .hero-title {
                font-size: 2.4rem;
            }
        }
        
        @media (max-width: 768px) {
            .hero-title {
                font-size: 2rem;
            }
            
            .hero-subtitle {
                font-size: 1rem;
            }
            
            .class-tabs {
                flex-wrap: nowrap;
                overflow-x: auto;
                justify-content: flex-start;
                padding-bottom: 10px;
                -webkit-overflow-scrolling: touch;
            }
            
            .filter-options {
                flex-direction: column;
                gap: 20px;
            }
            
            .filter-group {
                min-width: 100%;
            }
        }
        
        @media (max-width: 576px) {
            .hero-section {
                padding: 60px 20px;
            }
            
            .package-card {
                max-width: 100%;
            }
        }