:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --success-color: #28a745;
            --warning-color: #ffc107;
            --danger-color: #dc3545;
            --snake-color: #4caf50;
            --snake-head-color: #388e3c;
            --food-color: #f44336;
            --obstacle-color: #795548;
            --bg-game: #1a1a2e;
            --grid-color: #2d3047;
        }
 
         
        .game-area {
            display: flex;
            flex-direction: column;
            align-items: center;
            margin: 2rem 0;
        }
        
        .snake-game-container {
            width: 100%;
            max-width: 600px;
            height: 500px;
            background-color: var(--bg-game);
            border-radius: 10px;
            position: relative;
            overflow: hidden;
            margin-bottom: 2rem;
            border: 1px solid var(--border-color);
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        #gameCanvas {
            border-radius: 8px;
            background-color: var(--bg-game);
        }
        
        .game-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            background-color: rgba(26, 26, 46, 0.95);
            color: white;
            z-index: 10;
            border-radius: 8px;
            padding: 2rem;
            text-align: center;
        }
        
        .game-overlay h2 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
            color: #ff6b6b;
        }
        
        .game-overlay p {
            font-size: 1.2rem;
            margin-bottom: 1.5rem;
            max-width: 80%;
            line-height: 1.5;
        }
        
        .game-controls {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .game-btn {
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            font-weight: 600;
            transition: all 0.3s;
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .game-btn:disabled {
            opacity: 0.6;
            cursor: not-allowed;
            transform: none !important;
        }
        
        .game-btn-primary {
            background-color: var(--primary-color);
            color: white;
        }
        
        .game-btn-primary:hover:not(:disabled) {
            background-color: var(--accent-color);
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .game-btn-secondary {
            background-color: #6c757d;
            color: white;
        }
        
        .game-btn-secondary:hover:not(:disabled) {
            background-color: #5a6268;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .game-btn-success {
            background-color: var(--success-color);
            color: white;
        }
        
        .game-btn-success:hover:not(:disabled) {
            background-color: #218838;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .game-btn-warning {
            background-color: var(--warning-color);
            color: #212529;
        }
        
        .game-btn-warning:hover:not(:disabled) {
            background-color: #e0a800;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .game-stats {
            display: flex;
            justify-content: space-around;
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid var(--border-color);
        }
        
        .stat-item {
            text-align: center;
        }
        
        .stat-value {
            font-size: 2rem;
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 0.25rem;
        }
        
        .stat-label {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        .game-info-box {
            background-color: rgba(44, 125, 160, 0.05);
            border-left: 3px solid var(--primary-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        
        .game-tip-box {
            background-color: rgba(255, 193, 7, 0.05);
            border-left: 3px solid var(--warning-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        
        .level-selection {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
            margin: 1.5rem 0;
            justify-content: center;
        }
        
        .level-btn {
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            font-weight: 600;
            background-color: white;
            border: 2px solid var(--border-color);
            transition: all 0.3s;
            cursor: pointer;
            min-width: 120px;
        }
        
        .level-btn:hover {
            background-color: var(--light-gray);
            transform: translateY(-2px);
        }
        
        .level-btn.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
            box-shadow: 0 4px 8px rgba(44, 125, 160, 0.2);
        }
        
        .victory-message {
            background: linear-gradient(135deg, rgba(40, 167, 69, 0.1) 0%, rgba(40, 167, 69, 0.3) 100%);
            border: 2px solid var(--success-color);
            border-radius: 8px;
            padding: 2rem;
            text-align: center;
            margin: 2rem 0;
            display: none;
        }
        
        .victory-title {
            font-size: 2rem;
            font-weight: 700;
            color: var(--success-color);
            margin-bottom: 1rem;
        }
         
        .difficulty-indicator {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 500;
            margin-right: 0.5rem;
        }
        
        .difficulty-easy {
            background-color: rgba(40, 167, 69, 0.1);
            color: #28a745;
        }
        
        .difficulty-medium {
            background-color: rgba(255, 193, 7, 0.1);
            color: #ffc107;
        }
        
        .difficulty-hard {
            background-color: rgba(220, 53, 69, 0.1);
            color: #dc3545;
        } 
        .strategy-tips {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .tip-card {
            background: white;
            border-radius: 8px;
            padding: 1.25rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            transition: transform 0.3s;
        }
        
        .tip-card:hover {
            transform: translateY(-5px);
        }
        
        .tip-icon {
            width: 48px;
            height: 48px;
            border-radius: 8px;
            background-color: rgba(44, 125, 160, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
            color: var(--primary-color);
            font-size: 1.25rem;
        }
        
        .tip-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        
        .tip-desc {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        .control-instructions {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .control-item {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1rem;
            text-align: center;
            border: 1px solid var(--border-color);
            transition: all 0.3s;
        }
        
        .control-item:hover {
            background-color: rgba(44, 125, 160, 0.05);
            transform: translateY(-3px);
        }
        
        .control-key {
            display: inline-block;
            width: 40px;
            height: 40px;
            background-color: white;
            border-radius: 6px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 0.5rem;
            font-weight: bold;
            border: 2px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            margin: 0 auto 0.5rem;
        }
        
        .high-scores {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid var(--border-color);
        }
        
        .score-item {
            display: flex;
            justify-content: space-between;
            padding: 0.75rem 0;
            border-bottom: 1px solid rgba(0,0,0,0.1);
            align-items: center;
        }
        
        .score-item:last-child {
            border-bottom: none;
        }
        
        .score-rank {
            font-weight: bold;
            color: var(--primary-color);
            width: 30px;
            text-align: center;
        }
        
        .score-name {
            flex: 1;
            padding: 0 1rem;
        }
        
        .score-value {
            font-weight: bold;
            min-width: 60px;
            text-align: right;
        }
        
        .mobile-controls {
            display: none;
            grid-template-columns: repeat(3, 1fr);
            grid-template-rows: repeat(2, 1fr);
            gap: 10px;
            margin-top: 1rem;
            width: 100%;
            max-width: 300px;
        }
        
        .mobile-btn {
            background-color: rgba(255, 255, 255, 0.9);
            border-radius: 50%;
            width: 70px;
            height: 70px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            box-shadow: 0 4px 8px rgba(0,0,0,0.2);
            border: 2px solid var(--border-color);
            user-select: none;
            cursor: pointer;
            transition: all 0.2s;
        }
        
        .mobile-btn:active {
            transform: scale(0.95);
            background-color: rgba(44, 125, 160, 0.1);
        }
        
        .mobile-btn.up {
            grid-column: 2;
            grid-row: 1;
        }
        
        .mobile-btn.left {
            grid-column: 1;
            grid-row: 2;
        }
        
        .mobile-btn.right {
            grid-column: 3;
            grid-row: 2;
        }
        
        .mobile-btn.down {
            grid-column: 2;
            grid-row: 2;
        }
        
        @media (max-width: 768px) {
            .tool-card {
                padding: 1.5rem;
            }
            
            .snake-game-container {
                height: 400px;
            }
            
            .game-controls {
                flex-direction: column;
                align-items: center;
            }
            
            .game-btn {
                width: 100%;
                max-width: 300px;
            }
            
            .game-stats {
                flex-direction: column;
                gap: 1rem;
            }
            
            .mobile-controls {
                display: grid;
            }
            
            .control-instructions {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .level-btn {
                min-width: 100px;
                padding: 0.75rem 1rem;
            }
        }
        
        @media (max-width: 480px) {
            .snake-game-container {
                height: 350px;
            }
            
            .game-overlay h2 {
                font-size: 2rem;
            }
            
            .control-instructions {
                grid-template-columns: 1fr;
            }
        }
        
        .toast-container {
            position: fixed;
            bottom: 20px;
            right: 20px;
            z-index: 1050;
        }
        
        @keyframes pulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); }
        }
        
        .pulse {
            animation: pulse 0.5s ease;
        }
        
        .form-control {
            border: 1px solid #ddd;
            border-radius: 6px;
            padding: 0.75rem;
            transition: all 0.3s;
        }
        
        .form-control:focus {
            border-color: var(--primary-color);
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.15);
        }
        
        .btn {
            border-radius: 6px;
            padding: 0.75rem 1.5rem;
            font-weight: 600;
            transition: all 0.3s;
            cursor: pointer;
        }
        
        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }
        
        .btn-primary:hover {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            transform: translateY(-1px);
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .btn-outline-primary {
            color: var(--primary-color);
            border-color: var(--primary-color);
        }
        
        .btn-outline-primary:hover {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            color: white;
        }
        
        .alert {
            border-radius: 6px;
            border: 1px solid transparent;
            padding: 1rem;
            margin-bottom: 1rem;
        }
        
        .alert-success {
            background-color: rgba(40, 167, 69, 0.1);
            border-color: rgba(40, 167, 69, 0.2);
            color: #155724;
        }
        
        .alert-info {
            background-color: rgba(23, 162, 184, 0.1);
            border-color: rgba(23, 162, 184, 0.2);
            color: #0c5460;
        }
        
        .alert-warning {
            background-color: rgba(255, 193, 7, 0.1);
            border-color: rgba(255, 193, 7, 0.2);
            color: #856404;
        }
        
        .alert-danger {
            background-color: rgba(220, 53, 69, 0.1);
            border-color: rgba(220, 53, 69, 0.2);
            color: #721c24;
        }
        
        hr {
            border: 0;
            border-top: 1px solid var(--border-color);
            margin: 1.5rem 0;
        }
        
        .text-muted {
            color: var(--text-muted) !important;
        }
        
        .text-success {
            color: var(--success-color) !important;
        }
        
        .text-warning {
            color: var(--warning-color) !important;
        }
        
        .text-danger {
            color: var(--danger-color) !important;
        }
        
        .text-primary {
            color: var(--primary-color) !important;
        }
        
        .table {
            width: 100%;
            margin-bottom: 1rem;
            color: var(--text-color);
        }
        
        .table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .table-striped tbody tr:nth-of-type(odd) {
            background-color: rgba(0, 0, 0, 0.02);
        }
        
        .table-bordered {
            border: 1px solid var(--border-color);
        }
        
        .table-bordered th,
        .table-bordered td {
            border: 1px solid var(--border-color);
        }
        
       
        
        .faq-section {
            margin-top: 2rem;
        }
        
        .accordion-button:not(.collapsed) {
            background-color: rgba(44, 125, 160, 0.1);
            color: var(--primary-color);
            font-weight: 600;
        }
        
        .accordion-button:focus {
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.25);
            border-color: var(--primary-color);
        }
         
        .game-settings {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid var(--border-color);
        }
        
        .setting-option {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.75rem 0;
            border-bottom: 1px solid rgba(0,0,0,0.1);
        }
        
        .setting-option:last-child {
            border-bottom: none;
        }
        
        .form-check-input:checked {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }
        
        .form-check-input:focus {
            box-shadow: 0 0 0 3px rgba(44, 125, 160, 0.25);
        }
        
        .powerup {
            display: inline-block;
            width: 24px;
            height: 24px;
            border-radius: 50%;
            margin: 0 5px;
            vertical-align: middle;
        }
        
        .powerup.food {
            background-color: var(--food-color);
        }
        
        .powerup.speed {
            background-color: #ff9800;
        }
        
        .powerup.slow {
            background-color: #2196f3;
        }
        
        .powerup.wall {
            background-color: var(--obstacle-color);
        }
        
        .progress-bar {
            height: 8px;
            background-color: var(--primary-color);
            border-radius: 4px;
            margin-top: 0.5rem;
            transition: width 0.3s;
        }
        
        .speed-indicator {
            display: flex;
            align-items: center;
            margin-top: 0.5rem;
        }
        
        .speed-label {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-right: 1rem;
        }
        
        .speed-slider {
            flex: 1;
            -webkit-appearance: none;
            height: 6px;
            border-radius: 3px;
            background: #ddd;
            outline: none;
        }
        
        .speed-slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            appearance: none;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background: var(--primary-color);
            cursor: pointer;
            border: 2px solid white;
            box-shadow: 0 2px 4px rgba(0,0,0,0.2);
        }
        
        .tutorial-overlay {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(26, 26, 46, 0.95);
            color: white;
            z-index: 20;
            border-radius: 8px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: 2rem;
        }
        
        .tutorial-step {
            display: none;
            max-width: 500px;
        }
        
        .tutorial-step.active {
            display: block;
        }
        
        .tutorial-step h3 {
            margin-bottom: 1rem;
            color: #4ecdc4;
        }
        
        .tutorial-step p {
            margin-bottom: 1.5rem;
            line-height: 1.5;
        }
        
        .tutorial-navigation {
            display: flex;
            gap: 1rem;
            margin-top: 2rem;
        }
        
        .skip-tutorial {
            background: transparent;
            border: none;
            color: #aaa;
            cursor: pointer;
            margin-top: 1rem;
            text-decoration: underline;
        }
        
        .skip-tutorial:hover {
            color: white;
        }
        
        .help-btn {
            position: absolute;
            top: 15px;
            right: 15px;
            width: 30px;
            height: 30px;
            border-radius: 50%;
            background-color: rgba(255,255,255,0.2);
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            cursor: pointer;
            z-index: 15;
            font-size: 0.9rem;
            border: 1px solid rgba(255,255,255,0.3);
        }
        
        .help-btn:hover {
            background-color: rgba(255,255,255,0.3);
        }
        
        .adaptive-speed {
            margin-top: 1rem;
            padding: 1rem;
            background-color: rgba(44, 125, 160, 0.05);
            border-radius: 6px;
            border-left: 3px solid var(--primary-color);
        }
        
        .adaptive-speed label {
            display: flex;
            align-items: center;
            cursor: pointer;
        }
        
        .adaptive-speed input {
            margin-right: 0.5rem;
        }