
        @import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;600;700&display=swap');
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Poppins', sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            color: white;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }
        
        /* Homepage Styles */
        .homepage {
            display: flex;
            flex-direction: column;
            align-items: center;
            text-align: center;
            min-height: 80vh;
            justify-content: center;
        }
        
        .hero {
            margin-bottom: 50px;
        }
        
        .hero h1 {
            font-size: 4rem;
            font-weight: 700;
            margin-bottom: 20px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
            background: linear-gradient(45deg, #fff, #f0f8ff);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        
        .hero p {
            font-size: 1.3rem;
            opacity: 0.9;
            max-width: 600px;
            line-height: 1.6;
            margin-bottom: 30px;
        }
        
        .features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
            margin-bottom: 50px;
            width: 100%;
        }
        
        .feature-card {
            background: rgba(255,255,255,0.1);
            padding: 30px;
            border-radius: 20px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255,255,255,0.2);
            transition: transform 0.3s ease;
        }
        
        .feature-card:hover {
            transform: translateY(-5px);
        }
        
        .feature-card h3 {
            font-size: 1.5rem;
            margin-bottom: 15px;
            color: #fff;
        }
        
        .feature-card p {
            opacity: 0.8;
            line-height: 1.5;
        }
        
        .category-selection {
            margin-bottom: 40px;
        }
        
        .category-selection h3 {
            font-size: 1.8rem;
            margin-bottom: 20px;
        }
        
        .categories {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
            gap: 15px;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .category-btn {
            background: rgba(255,255,255,0.2);
            border: 2px solid rgba(255,255,255,0.3);
            color: white;
            padding: 15px 20px;
            border-radius: 15px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            backdrop-filter: blur(10px);
        }
        
        .category-btn:hover,
        .category-btn.selected {
            background: rgba(255,255,255,0.3);
            border-color: rgba(255,255,255,0.6);
            transform: translateY(-2px);
        }
        
        .start-btn {
            background: linear-gradient(145deg, #4facfe, #00f2fe);
            color: white;
            border: none;
            padding: 20px 40px;
            border-radius: 30px;
            font-size: 1.3rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 10px 30px rgba(79,172,254,0.3);
            margin-top: 30px;
        }
        
        .start-btn:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 40px rgba(79,172,254,0.4);
        }
        
        /* Game Styles */
        .game-container {
            display: none;
        }
        
        .game-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
            flex-wrap: wrap;
            gap: 20px;
        }
        
        .game-title {
            font-size: 2rem;
            font-weight: 700;
        }
        
        .difficulty-indicator {
            background: rgba(255,255,255,0.2);
            padding: 10px 20px;
            border-radius: 25px;
            backdrop-filter: blur(10px);
            font-weight: 600;
        }
        
        .game-stats {
            display: flex;
            gap: 20px;
            margin-bottom: 30px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .stat {
            background: rgba(255,255,255,0.2);
            padding: 12px 24px;
            border-radius: 25px;
            backdrop-filter: blur(10px);
            font-weight: 600;
            min-width: 120px;
            text-align: center;
        }
        
        .game-board {
            display: grid;
            gap: 15px;
            max-width: 800px;
            margin: 0 auto 30px;
            justify-content: center;
        }
        
        .board-2x6 { grid-template-columns: repeat(4, 1fr); }
        .board-3x6 { grid-template-columns: repeat(6, 1fr); }
        .board-4x6 { grid-template-columns: repeat(6, 1fr); }
        
        .card {
            width: 100px;
            height: 100px;
            background: linear-gradient(145deg, #ffffff, #f0f0f0);
            border-radius: 15px;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 8px 20px rgba(0,0,0,0.1);
            position: relative;
            transform-style: preserve-3d;
        }
        
        .card:hover {
            transform: translateY(-5px);
            box-shadow: 0 12px 25px rgba(0,0,0,0.2);
        }
        
        .card.flipped {
            background: linear-gradient(145deg, #4facfe, #00f2fe);
            transform: rotateY(180deg);
        }
        
        .card.matched {
            background: linear-gradient(145deg, #a8edea, #fed6e3);
            transform: scale(0.95);
            cursor: default;
        }
        
        .card-content {
            font-size: 2.5rem;
            opacity: 0;
            transition: opacity 0.3s ease;
        }
        
        .card.flipped .card-content,
        .card.matched .card-content {
            opacity: 1;
        }
        
        .game-controls {
            display: flex;
            gap: 20px;
            justify-content: center;
            flex-wrap: wrap;
        }
        
        .btn {
            padding: 12px 24px;
            border: none;
            border-radius: 25px;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .btn-primary {
            background: linear-gradient(145deg, #667eea, #764ba2);
            color: white;
        }
        
        .btn-secondary {
            background: linear-gradient(145deg, #ff6b6b, #ee5a24);
            color: white;
        }
        
        .btn:hover {
            transform: translateY(-2px);
        }
        
        /* Modal Styles */
        .modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.8);
            display: none;
            align-items: center;
            justify-content: center;
            z-index: 1000;
        }
        
        .modal-content {
            background: white;
            color: #333;
            padding: 40px;
            border-radius: 20px;
            max-width: 500px;
            text-align: center;
            box-shadow: 0 20px 40px rgba(0,0,0,0.3);
            animation: slideIn 0.3s ease;
        }
        
        @keyframes slideIn {
            from { transform: translateY(-50px); opacity: 0; }
            to { transform: translateY(0); opacity: 1; }
        }
        
        .modal-content h3 {
            color: #667eea;
            font-size: 1.5rem;
            margin-bottom: 20px;
        }
        
        .modal-content p {
            font-size: 1.1rem;
            margin-bottom: 30px;
            line-height: 1.6;
        }
        
        /* Footer */
        .footer {
            background: rgba(0,0,0,0.2);
            text-align: center;
            padding: 30px 20px;
            margin-top: 50px;
            backdrop-filter: blur(10px);
        }
        
        .footer p {
            margin-bottom: 10px;
            opacity: 0.8;
        }
        
        .footer a {
            color: #4facfe;
            text-decoration: none;
            font-weight: 600;
        }
        
        .footer a:hover {
            text-decoration: underline;
        }
        
        /* Responsive Design */
        @media (max-width: 768px) {
            .hero h1 {
                font-size: 2.5rem;
            }
            
            .features {
                grid-template-columns: 1fr;
            }
            
            .categories {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .card {
                width: 80px;
                height: 80px;
            }
            
            .card-content {
                font-size: 2rem;
            }
            
            .game-header {
                flex-direction: column;
                text-align: center;
            }
            
            .game-stats {
                justify-content: center;
            }
        }
        
        .level-complete {
            background: linear-gradient(145deg, #4facfe, #00f2fe);
            color: white;
            padding: 20px;
            border-radius: 15px;
            margin: 20px 0;
            text-align: center;
            animation: celebration 0.5s ease;
        }
        
        @keyframes celebration {
            0% { transform: scale(0.8); opacity: 0; }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); opacity: 1; }
        }
    