:root {
            --primary-color: #3498db;
            --secondary-color: #2ecc71;
            --accent-color: #e74c3c;
            --warning-color: #f39c12;
            --dark-color: #2c3e50;
            --light-color: #ecf0f1;
            --text-color: #333;
            --text-muted: #7f8c8d;
            --sky-color: #87CEEB;
            --cloud-color: #ffffff;
            --obstacle-color: #e74c3c;
            --fuel-color: #f1c40f;
            --heli-body: #7f8c8d;
            --heli-main: #34495e;
            --heli-blade: #95a5a6;
        }
         
        .page-header {
            background: linear-gradient(135deg, rgba(52, 152, 219, 0.2) 0%, rgba(46, 204, 113, 0.2) 100%);
            padding: 2rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(52, 152, 219, 0.2);color:var(--text-color);
        }
        
        .game-card {
            background: white;
            border-radius: 12px;
            border: 1px solid #eaeaea;
            padding: 2rem;
            margin-bottom: 2rem;
            box-shadow: 0 4px 12px rgba(0,0,0,0.08);
        }
        
        .game-title {
            font-weight: 700;
            color: var(--dark-color);
            margin-bottom: 0.5rem;
            padding-bottom: 0.75rem;
            border-bottom: 2px solid var(--primary-color);
        }
        
        .game-container {
            position: relative;
            width: 100%;
            height: 550px;
            background: linear-gradient(to bottom, var(--sky-color) 0%, #5dade2 100%);
            border-radius: 8px;
            overflow: hidden;
            border: 3px solid var(--dark-color);
            margin: 1.5rem 0;
            cursor: pointer;
        }
        
        #gameCanvas {
            width: 100%;
            height: 100%;
        }
        
        .game-ui-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 10;
        }
        
        .game-stats {
            display: flex;
            justify-content: space-between;
            background-color: rgba(44, 62, 80, 0.85);
            color: white;
            padding: 0.75rem 1.5rem;
            border-radius: 0 0 8px 8px;
        }
        
        .stat-item {
            text-align: center;
        }
        
        .stat-value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--secondary-color);
            margin-bottom: 0.25rem;
        }
        
        .stat-label {
            color: var(--light-color);
            font-size: 0.85rem;
        }
        
        .game-controls {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
            margin: 1.5rem 0;
            justify-content: center;
        }
        
        .game-btn {
            padding: 0.85rem 1.75rem;
            border-radius: 8px;
            font-weight: 600;
            transition: all 0.3s;
            border: none;
            display: flex;
            align-items: center;
            justify-content: center;
            min-width: 140px;
        }
        
        .game-btn-primary {
            background-color: var(--primary-color);
            color: white;
        }
        
        .game-btn-primary:hover {
            background-color: #2980b9;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(52, 152, 219, 0.3);
        }
        
        .game-btn-success {
            background-color: var(--secondary-color);
            color: white;
        }
        
        .game-btn-success:hover {
            background-color: #27ae60;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(46, 204, 113, 0.3);
        }
        
        .game-btn-warning {
            background-color: var(--warning-color);
            color: white;
        }
        
        .game-btn-warning:hover {
            background-color: #e67e22;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(243, 156, 18, 0.3);
        }
        
        .game-btn-danger {
            background-color: var(--accent-color);
            color: white;
        }
        
        .game-btn-danger:hover {
            background-color: #c0392b;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(231, 76, 60, 0.3);
        }
        
        .game-instructions {
            background-color: rgba(52, 152, 219, 0.1);
            border-left: 3px solid var(--primary-color);
            padding: 1.25rem;
            border-radius: 0 8px 8px 0;
            margin: 1.5rem 0;
        }
        
        .difficulty-selector {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
            margin: 1.5rem 0;
        }
        
        .difficulty-btn {
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            font-weight: 600;
            background-color: white;
            border: 2px solid #ddd;
            transition: all 0.3s;
        }
        
        .difficulty-btn:hover {
            background-color: #f8f9fa;
        }
        
        .difficulty-btn.active {
            border-color: var(--primary-color);
            background-color: var(--primary-color);
            color: white;
        }
        
        .difficulty-easy {
            border-color: var(--secondary-color);
            color: var(--secondary-color);
        }
        
        .difficulty-easy.active {
            background-color: var(--secondary-color);
            color: white;
        }
        
        .difficulty-medium {
            border-color: var(--warning-color);
            color: var(--warning-color);
        }
        
        .difficulty-medium.active {
            background-color: var(--warning-color);
            color: white;
        }
        
        .difficulty-hard {
            border-color: var(--accent-color);
            color: var(--accent-color);
        }
        
        .difficulty-hard.active {
            background-color: var(--accent-color);
            color: white;
        }
        
        .powerup-info {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .powerup-card {
            background: white;
            border-radius: 8px;
            padding: 1rem;
            border: 1px solid #eaeaea;
            display: flex;
            align-items: center;
            transition: transform 0.3s;
        }
        
        .powerup-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .powerup-icon {
            width: 50px;
            height: 50px;
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 1rem;
            font-size: 1.5rem;
            color: white;
        }
        
        .powerup-icon.fuel {
            background-color: var(--fuel-color);
        }
        
        .powerup-icon.shield {
            background-color: var(--primary-color);
        }
        
        .powerup-icon.speed {
            background-color: var(--secondary-color);
        }
        
        .powerup-icon.magnet {
            background-color: #9b59b6;
        }
        
        .powerup-name {
            font-weight: 600;
            margin-bottom: 0.25rem;
        }
        
        .powerup-desc {
            color: var(--text-muted);
            font-size: 0.85rem;
        }
        
        .controls-info {
            background-color: rgba(243, 156, 18, 0.1);
            border-left: 3px solid var(--warning-color);
            padding: 1.25rem;
            border-radius: 0 8px 8px 0;
            margin: 1.5rem 0;
        }
        
        .key-control {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            background-color: var(--dark-color);
            color: white;
            border-radius: 4px;
            font-family: monospace;
            font-weight: bold;
            margin: 0 0.25rem;
        }
        
        .leaderboard {
            background-color: white;
            border-radius: 8px;
            border: 1px solid #eaeaea;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
        }
        
        .leaderboard-title {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--dark-color);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid #eaeaea;
        }
        
        .leaderboard-item {
            display: flex;
            justify-content: space-between;
            padding: 0.75rem;
            border-bottom: 1px solid #f1f1f1;
        }
        
        .leaderboard-item:last-child {
            border-bottom: none;
        }
        
        .leaderboard-rank {
            font-weight: 700;
            color: var(--primary-color);
            width: 30px;
        }
        
        .leaderboard-player {
            flex: 1;
        }
        
        .leaderboard-score {
            font-weight: 600;
            color: var(--dark-color);
        }
        
        .game-modal {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.85);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 100;
            border-radius: 8px;
        }
        
        .modal-content {
            background-color: white;
            border-radius: 12px;
            padding: 2rem;
            max-width: 500px;
            width: 90%;
            text-align: center;
        }
        
        .modal-title {
            font-size: 2rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: var(--dark-color);
        }
        
        .modal-score {
            font-size: 3rem;
            font-weight: 700;
            color: var(--primary-color);
            margin: 1rem 0;
        }
        
        .modal-message {
            color: var(--text-muted);
            margin-bottom: 1.5rem;
            font-size: 1.1rem;
        }
        
        .mobile-controls {
            display: none;
            position: absolute;
            bottom: 20px;
            width: 100%;
            justify-content: space-between;
            padding: 0 2rem;
            pointer-events: auto;
            z-index: 20;
        }
        
        .mobile-btn {
            width: 70px;
            height: 70px;
            border-radius: 50%;
            background-color: rgba(52, 152, 219, 0.8);
            color: white;
            border: none;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
        }
        
        @media (max-width: 768px) {
            .game-container {
                height: 820px;
            }
            
            .game-stats {
                flex-direction: column;
                gap: 0.5rem;
                padding: 0.5rem;
            }
            
            .stat-item {
                display: flex;
                justify-content: space-between;
            }
            
            .mobile-controls {
                display: flex;
            }
            
            .powerup-info {
                grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
            }
        }
        
        @media (max-width: 480px) {
            .game-container {
                height: 820px;
            }
            
            .game-btn {
                min-width: 120px;
                padding: 0.75rem 1rem;
            }
            
            .mobile-btn {
                width: 60px;
                height: 60px;
                font-size: 1.25rem;
            }
        }
        
        .progress-bar-container {
            width: 100%;
            height: 10px;
            background-color: #e0e0e0;
            border-radius: 5px;
            overflow: hidden;
            margin: 1rem 0;
        }
        
        .progress-bar {
            height: 100%;
            background-color: var(--primary-color);
            width: 100%;
            transition: width 0.3s;
        }
        
        .fuel-bar {
            background-color: var(--fuel-color);
        }
        
        .cloud {
            position: absolute;
            background-color: var(--cloud-color);
            border-radius: 50%;
            opacity: 0.8;
            z-index: 1;
        }
        
        .obstacle {
            position: absolute;
            background-color: var(--obstacle-color);
            border-radius: 4px;
            z-index: 2;
        }
        
        .powerup {
            position: absolute;
            border-radius: 50%;
            z-index: 3;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
            font-size: 0.8rem;
        }
        
        .footer {
            background-color: #2c3e50;
            color: white;
            margin-top: 3rem;
            padding: 2rem 0;
        }
        
        .section-title {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--dark-color);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid #eaeaea;
        }
        
        .helicopter {
            position: absolute;
            z-index: 5;
            transition: transform 0.1s;
        }
        
        .heli-body {
            width: 40px;
            height: 20px;
            background-color: var(--heli-body);
            border-radius: 5px;
            position: relative;
        }
        
        .heli-cabin {
            width: 30px;
            height: 15px;
            background-color: var(--heli-main);
            border-radius: 3px;
            position: absolute;
            top: -10px;
            left: 5px;
        }
        
        .heli-tail {
            width: 20px;
            height: 5px;
            background-color: var(--heli-main);
            position: absolute;
            top: 5px;
            left: -15px;
        }
        
        .heli-rotor {
            width: 50px;
            height: 5px;
            background-color: var(--heli-blade);
            position: absolute;
            top: -15px;
            left: -5px;
            border-radius: 2px;
        }
        
        .heli-rotor::after {
            content: '';
            position: absolute;
            width: 5px;
            height: 50px;
            background-color: var(--heli-blade);
            top: -22.5px;
            left: 22.5px;
            border-radius: 2px;
        }
        
        .blade-animation {
            animation: rotateBlade 0.1s linear infinite;
        }
        
        @keyframes rotateBlade {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        .pulse {
            animation: pulse 0.5s ease;
        }
        
        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); }
        }
        
        .shake {
            animation: shake 0.5s ease;
        }
        
        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
            20%, 40%, 60%, 80% { transform: translateX(5px); }
        }
        
        .flash {
            animation: flash 0.3s ease;
        }
        
        @keyframes flash {
            0%, 100% { opacity: 1; }
            50% { opacity: 0.5; }
        }
        
        .game-tip {
            background-color: rgba(46, 204, 113, 0.1);
            border-left: 3px solid var(--secondary-color);
            padding: 1rem;
            border-radius: 0 8px 8px 0;
            margin: 1rem 0;
        }