:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --correct-color: #28a745;
            --incorrect-color: #dc3545;
            --current-color: #ffc107;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background-color: white;
            color: var(--text-color);
            line-height: 1.6;
        }
        
        .container {
            max-width: 1200px;
        }
        
        /* Header Styles */
        .navbar {
            background-color: white;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
            border-bottom: 1px solid var(--border-color);
            padding: 0.75rem 0;
        }
        
        .navbar-brand {
            font-weight: 700;
            color: var(--primary-color);
            font-size: 1.5rem;
        }
        
        .nav-link {
            color: #555;
            font-weight: 500;
            transition: color 0.3s;
            padding: 0.5rem 1rem;
            border-radius: 6px;
        }
        
        .nav-link:hover, .nav-link.active {
            color: var(--primary-color);
            background-color: rgba(44, 125, 160, 0.1);
        }
        
        .page-header {
            background: linear-gradient(135deg, rgba(169, 214, 229, 0.4) 0%, rgba(44, 125, 160, 0.4) 100%);
            padding: 1.5rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(44, 125, 160, 0.2);
            position: relative;
            overflow: hidden;
        }
        
        .page-header::before {
            content: "";
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background-image: radial-gradient(rgba(255,255,255,0.8) 1px, transparent 1px);
            background-size: 20px 20px;
            opacity: 0.3;
            transform: rotate(30deg);
        }
        
        .breadcrumb {
            background-color: transparent;
            padding: 0.5rem 0;
            margin-bottom: 0.5rem;
        }
        
        .breadcrumb-item a {
            color: var(--text-muted);
            text-decoration: none;
        }
        
        .breadcrumb-item.active {
            color: var(--text-color);
        }
        
        /* Tool Card Styles */
        .tool-card {
            background: white;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            padding: 2rem;
            margin-bottom: 1.5rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.03);
        }
        
        .tool-header {
            position: relative;
            padding-bottom: 15px;
            margin-bottom: 25px;
            border-bottom: 1px solid var(--border-color);
        }
        
        .tool-header h2 {
            font-weight: 600;
            color: var(--primary-color);
            margin-bottom: 0.5rem;
        }
        
        /* Test Tabs */
        .test-tabs {
            display: flex;
            gap: 0.5rem;
            margin-bottom: 1.5rem;
            flex-wrap: wrap;
        }
        
        .test-tab {
            padding: 0.75rem 1.5rem;
            background-color: var(--light-gray);
            border: 1px solid var(--border-color);
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 500;
        }
        
        .test-tab:hover {
            background-color: #e9ecef;
        }
        
        .test-tab.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }
        
        /* Test Area */
        .test-area {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 2rem;
            margin-bottom: 1.5rem;
            border: 1px solid var(--border-color);
            min-height: 400px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
        }
        
        .test-instructions {
            margin-bottom: 1.5rem;
            max-width: 600px;
        }
        
        .test-content {
            width: 100%;
            margin: 1.5rem 0;
        }
        
        .test-controls {
            display: flex;
            justify-content: center;
            gap: 1rem;
            margin-top: 1.5rem;
        }
        
        .btn-lg {
            padding: 0.75rem 2rem;
            font-size: 1.1rem;
            font-weight: 600;
        }
        
        .btn-success {
            background-color: #28a745;
            border-color: #28a745;
        }
        
        .btn-warning {
            background-color: #ffc107;
            border-color: #ffc107;
            color: #333;
        }
        
        .btn-warning:hover {
            background-color: #e0a800;
            border-color: #d39e00;
        }
        
        .btn-danger {
            background-color: #dc3545;
            border-color: #dc3545;
        }
        
        /* Memory Grid */
        .memory-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 1rem;
            max-width: 600px;
            margin: 0 auto;
        }
        
        .memory-card {
            width: 100%;
            aspect-ratio: 1/1;
            background-color: var(--primary-color);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 2rem;
            font-weight: bold;
            color: white;
            cursor: pointer;
            transition: all 0.3s;
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
        }
        
        .memory-card.hidden {
            background-color: var(--light-gray);
            color: transparent;
        }
        
        .memory-card.correct {
            background-color: var(--correct-color);
        }
        
        .memory-card.incorrect {
            background-color: var(--incorrect-color);
        }
        
        /* Sequence Test */
        .sequence-container {
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 1rem;
            margin-bottom: 2rem;
        }
        
        .sequence-item {
            width: 60px;
            height: 60px;
            border-radius: 50%;
            background-color: var(--primary-color);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.5rem;
            font-weight: bold;
            color: white;
        }
        
        .sequence-item.hidden {
           # background-color: var(--light-gray);
       background-color:#adb5bd
        }
        
        /* Number Test */
        .number-display {
            font-size: 3rem;
            font-weight: bold;
            margin: 2rem 0;
            padding: 1rem 2rem;
            background-color: var(--light-gray);
            border-radius: 8px;
            min-width: 300px;
        }
        
        .number-input {
            font-size: 1.5rem;
            padding: 0.75rem 1.5rem;
            width: 300px;
            text-align: center;
            border-radius: 8px;
            border: 2px solid var(--border-color);
        }
        
        /* Results Area */
        .results-container {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 2rem;
            margin-top: 2rem;
            border: 1px solid var(--border-color);
        }
        
        .results-header {
            font-weight: 600;
            margin-bottom: 1.5rem;
            color: var(--primary-color);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid var(--border-color);
        }
        
        .test-stats {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin: 1.5rem 0;
        }
        
        .stat-card {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }
        
        .stat-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--primary-color);
        }
        
        .stat-value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--accent-color);
            margin-bottom: 0.5rem;
        }
        
        .stat-desc {
            color: var(--text-muted);
        }
        
        .chart-container {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            margin-top: 1.5rem;
            border: 1px solid var(--border-color);
            height: 300px; display:none
        }
        
        .chart-title {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--primary-color);
            padding-bottom: 0.5px;
            border-bottom: 1px solid var(--border-color);
        }
        
        /* Content Cards */
        .content-card {
            background: white;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.03);
        }
        
        .content-header {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--primary-color);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid var(--border-color);
        }
        
        .content-body {
            line-height: 1.8;
        }
        
        .content-highlight {
            background-color: rgba(44, 125, 160, 0.1);
            border-left: 3px solid var(--primary-color);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1rem 0;
        }
        
        .content-list {
            padding-left: 1.5rem;
            margin: 1rem 0;
        }
        
        .content-list li {
            margin-bottom: 0.5rem;
        }
        
        .content-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 1.5rem 0;
        }
        
        .content-item {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
        }
        
        .content-item-icon {
            font-size: 2rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        
        .content-item-title {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--primary-color);
        }
        
        /* Toast notifications */
        .toast-container {
            position: fixed;
            bottom: 20px;
            right: 20px;
            z-index: 1050;
        }
        
        .toast {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 1rem;
            display: flex;
            align-items: center;
            gap: 1rem;
            max-width: 350px;
            transform: translateY(100px);
            opacity: 0;
            transition: all 0.3s ease;
        }
        
        .toast.show {
            transform: translateY(0);
            opacity: 1;
        }
        
        .toast-success {
            border-left: 4px solid #2ecc71;
        }
        
        .toast-error {
            border-left: 4px solid #e74c3c;
        }
        
        .toast-info {
            border-left: 4px solid #3498db;
        }
        
        .toast-icon {
            font-size: 1.5rem;
        }
        
        .toast-success .toast-icon {
            color: #2ecc71;
        }
        
        .toast-error .toast-icon {
            color: #e74c3c;
        }
        
        .toast-info .toast-icon {
            color: #3498db;
        }
        
        /* Responsive Adjustments */
        @media (max-width: 768px) {
            .tool-card {
                padding: 1.5rem;
            }
            
            .memory-grid {
                grid-template-columns: repeat(3, 1fr);
                gap: 0.75rem;
            }
            
            .sequence-container {
                gap: 0.5rem;
            }
            
            .sequence-item {
                width: 50px;
                height: 50px;
                font-size: 1.2rem;
            }
        }