@import url('https://cdnjs.cloudflare.com/ajax/libs/tailwindcss/2.2.19/tailwind.min.css');
        @import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;700;900&display=swap');
        
        body {
            font-family: 'Orbitron', monospace;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            animation: backgroundShift 10s ease-in-out infinite;
        }
        
        @keyframes backgroundShift {
            0%, 100% { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); }
            50% { background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%); }
        }
        
        .game-container {
            background: rgba(0, 0, 0, 0.8);
            backdrop-filter: blur(10px);
            border: 2px solid rgba(255, 255, 255, 0.1);
            box-shadow: 0 25px 50px rgba(0, 0, 0, 0.5);
        }
        
        .game-board {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 3px solid #0f3460;
            box-shadow: 
                inset 0 0 20px rgba(0, 212, 255, 0.3),
                0 0 40px rgba(0, 212, 255, 0.2);
        }
        
        .sidebar-panel {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 2px solid rgba(0, 212, 255, 0.3);
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
            backdrop-filter: blur(10px);
        }
        
        .neon-button {
            background: linear-gradient(145deg, #0f3460, #1a1a2e);
            border: 2px solid #00d4ff;
            color: #00d4ff;
            text-shadow: 0 0 10px #00d4ff;
            box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
            transition: all 0.3s ease;
        }
        
        .neon-button:hover {
            box-shadow: 0 0 30px rgba(0, 212, 255, 0.6);
            transform: translateY(-2px);
        }
        
        .neon-button.active {
            background: linear-gradient(145deg, #00d4ff, #0099cc);
            color: #000;
            text-shadow: none;
        }
        
        .score-display {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 2px solid #00ff88;
            color: #00ff88;
            text-shadow: 0 0 10px #00ff88;
            box-shadow: 0 0 20px rgba(0, 255, 136, 0.3);
        }
        
        .next-piece-container {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 2px solid #ff6b6b;
            box-shadow: 0 0 20px rgba(255, 107, 107, 0.3);
        }
        
        .difficulty-selector {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 2px solid #ffd93d;
            box-shadow: 0 0 20px rgba(255, 217, 61, 0.3);
        }
        
        .game-cell {
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: all 0.2s ease;
        }
        
        .game-cell.filled {
            border: 2px solid rgba(255, 255, 255, 0.8);
            box-shadow: 0 0 10px rgba(255, 255, 255, 0.3);
        }
        
        .preview-cell {
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: all 0.2s ease;
        }
        
        .preview-cell.filled {
            border: 1px solid rgba(255, 255, 255, 0.6);
            box-shadow: 0 0 5px rgba(255, 255, 255, 0.3);
        }
        
        .tetris-I { 
            background: linear-gradient(145deg, #00f5ff, #0099cc);
            box-shadow: 0 0 15px rgba(0, 245, 255, 0.5);
        }
        .tetris-O { 
            background: linear-gradient(145deg, #ffff00, #cccc00);
            box-shadow: 0 0 15px rgba(255, 255, 0, 0.5);
        }
        .tetris-T { 
            background: linear-gradient(145deg, #a000ff, #7000cc);
            box-shadow: 0 0 15px rgba(160, 0, 255, 0.5);
        }
        .tetris-S { 
            background: linear-gradient(145deg, #00ff00, #00cc00);
            box-shadow: 0 0 15px rgba(0, 255, 0, 0.5);
        }
        .tetris-Z { 
            background: linear-gradient(145deg, #ff0000, #cc0000);
            box-shadow: 0 0 15px rgba(255, 0, 0, 0.5);
        }
        .tetris-J { 
            background: linear-gradient(145deg, #0000ff, #0000cc);
            box-shadow: 0 0 15px rgba(0, 0, 255, 0.5);
        }
        .tetris-L { 
            background: linear-gradient(145deg, #ff8000, #cc6600);
            box-shadow: 0 0 15px rgba(255, 128, 0, 0.5);
        }
        
        .modal-backdrop {
            background: rgba(0, 0, 0, 0.8);
            backdrop-filter: blur(10px);
        }
        
        .modal-content {
            background: linear-gradient(145deg, #1a1a2e, #16213e);
            border: 3px solid #00d4ff;
            box-shadow: 0 0 50px rgba(0, 212, 255, 0.5);
        }
        
        .particle {
            position: absolute;
            pointer-events: none;
            animation: particle 1s ease-out forwards;
        }
        
        @keyframes particle {
            0% {
                transform: translateY(0) scale(1);
                opacity: 1;
            }
            100% {
                transform: translateY(-100px) scale(0);
                opacity: 0;
            }
        }
        
        .combo-indicator {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            font-size: 2rem;
            font-weight: bold;
            color: #00ff88;
            text-shadow: 0 0 20px #00ff88;
            animation: comboShow 2s ease-out forwards;
            pointer-events: none;
        }
        
        @keyframes comboShow {
            0% {
                transform: translate(-50%, -50%) scale(0);
                opacity: 0;
            }
            20% {
                transform: translate(-50%, -50%) scale(1.2);
                opacity: 1;
            }
            80% {
                transform: translate(-50%, -50%) scale(1);
                opacity: 1;
            }
            100% {
                transform: translate(-50%, -50%) scale(0.8);
                opacity: 0;
            }
        }
        
        .level-indicator {
            background: linear-gradient(45deg, #ff6b6b, #ffd93d);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            animation: levelGlow 2s ease-in-out infinite;
        }
        
        @keyframes levelGlow {
            0%, 100% { text-shadow: 0 0 20px rgba(255, 107, 107, 0.5); }
            50% { text-shadow: 0 0 30px rgba(255, 217, 61, 0.8); }
        }