: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;
            --medical-red: #dc3545;
            --medical-green: #198754;
            --medical-yellow: #ffc107;
            --medical-orange: #fd7e14;
            --fitness-blue: #4361ee;
            --fitness-purple: #7209b7;
        }
         
        .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;   color: var(--text-color);
        }
         
        .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);
        }
         
        /* Financial Summary */
        .fitness-summary {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        
        .fitness-item {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .fitness-item h4 {
            font-size: 1rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        
        .fitness-item .value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        
        .fitness-item .detail {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
         
        
        .fitness-info-box {
            background-color: rgba(67, 97, 238, 0.05);
            border-left: 3px solid var(--fitness-blue);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
       
        
        /* Responsive Adjustments */
        @media (max-width: 768px) { 
            .fitness-summary {
                grid-template-columns: 1fr;
            }
        }
        
        /* Toggle switch for calculation modes */
        .calculation-modes {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 4px;
            margin-bottom: 1.5rem;
            flex-wrap: wrap;
        }
        
        .mode-btn {
            flex: 1;
            text-align: center;
            padding: 0.75rem;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
            min-width: 120px;
            margin: 2px;
        }
        
        .mode-btn.active {
            background-color: var(--primary-color);
            color: white;
        }
        
     
        /* Mode-specific form styling */
        .mode-form {
            display: none;
        }
        
        .mode-form.active {
            display: block;
        }
        
        /* Comparison table */
        .comparison-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .comparison-table th, .comparison-table td {
            padding: 0.75rem;
            text-align: left;
            border-bottom: 1px solid var(--border-color);
        }
        
        .comparison-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .comparison-table tr:hover {
            background-color: rgba(44, 125, 160, 0.05);
        }
        
        /* Fitness-specific styling */
        .fitness-alert {
            background-color: rgba(67, 97, 238, 0.1);
            border-left: 4px solid var(--fitness-blue);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        .excellent-range {
            color: var(--medical-green);
            font-weight: 600;
        }
        
        .good-range {
            color: #28a745;
            font-weight: 600;
        }
        
        .fair-range {
            color: var(--medical-yellow);
            font-weight: 600;
        }
        
        .poor-range {
            color: var(--medical-orange);
            font-weight: 600;
        }
        
        .very-poor-range {
            color: var(--medical-red);
            font-weight: 600;
        }
        
        .reference-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .reference-table th, .reference-table td {
            padding: 0.75rem;
            text-align: left;
            border: 1px solid var(--border-color);
        }
        
        .reference-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .reference-table tr:nth-child(even) {
            background-color: rgba(44, 125, 160, 0.05);
        }
        
        .generating-indicator {
            display: none;
            text-align: center;
            padding: 1rem;
            color: var(--text-muted);
        }
        
        /* VO2 Max specific styles */
        .vo2-chart-container {
            position: relative;
            height: 300px;
            width: 100%;
            margin: 1.5rem 0;
        }
        
        .fitness-status-indicator {
            display: inline-block;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            margin-right: 8px;
        }
        
        .status-excellent {
            background-color: var(--medical-green);
        }
        
        .status-good {
            background-color: #28a745;
        }
        
        .status-fair {
            background-color: var(--medical-yellow);
        }
        
        .status-poor {
            background-color: var(--medical-orange);
        }
        
        .status-very-poor {
            background-color: var(--medical-red);
        }
        
        .fitness-classification {
            padding: 1rem;
            border-radius: 8px;
            margin: 1rem 0;
            border-left: 5px solid;
        }
        
        .fitness-excellent {
            background-color: rgba(40, 167, 69, 0.1);
            border-left-color: var(--medical-green);
        }
        
        .fitness-good {
            background-color: rgba(40, 167, 69, 0.08);
            border-left-color: #28a745;
        }
        
        .fitness-fair {
            background-color: rgba(255, 193, 7, 0.1);
            border-left-color: var(--medical-yellow);
        }
        
        .fitness-poor {
            background-color: rgba(253, 126, 20, 0.1);
            border-left-color: var(--medical-orange);
        }
        
        .fitness-very-poor {
            background-color: rgba(220, 53, 69, 0.1);
            border-left-color: var(--medical-red);
        }
        
        /* Gender selector */
        .gender-selector {
            display: flex;
            gap: 10px;
            margin-bottom: 1rem;
        }
        
        .gender-btn {
            flex: 1;
            text-align: center;
            padding: 0.75rem;
            border: 1px solid #ddd;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
        }
        
        .gender-btn.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }
        
        /* Age group styling */
        .age-group-selector {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            margin-bottom: 1rem;
        }
        
        .age-group-btn {
            padding: 0.5rem 1rem;
            border: 1px solid #ddd;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 500;
            font-size: 0.9rem;
        }
        
        .age-group-btn.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }
        
        /* New styles for enhanced features */
        .unit-toggle {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 4px;
            margin-bottom: 1rem;
        }
        
        .unit-btn {
            flex: 1;
            text-align: center;
            padding: 0.5rem;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 500;
            font-size: 0.9rem;
        }
        
        .unit-btn.active {
            background-color: var(--primary-color);
            color: white;
        }
        
        .history-container {
            margin-top: 1.5rem;
            display: none;
        }
        
        .history-item {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 0.75rem;
            margin-bottom: 0.5rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .history-item:hover {
            background-color: var(--light-gray);
        }
        
        .history-date {
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        
        .history-value {
            font-weight: 600;
            color: var(--primary-color);
        }
        
        .export-options {
            display: flex;
            gap: 0.5rem;
            margin-top: 1rem;
            flex-wrap: wrap;
        }
        
        .export-btn {
            display: flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.5rem 1rem;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            background-color: white;
            color: var(--text-color);
            transition: all 0.3s;
        }
        
        .export-btn:hover {
            background-color: var(--light-gray);
            color: var(--primary-color);
        }
        
        .input-error {
            border-color: var(--medical-red) !important;
            box-shadow: 0 0 0 3px rgba(220, 53, 69, 0.15) !important;
        }
        
        .error-message {
            color: var(--medical-red);
            font-size: 0.875rem;
            margin-top: 0.25rem;
            display: none;
        }
        
        .progress-indicator {
            display: none;
            text-align: center;
            padding: 1rem;
            color: var(--primary-color);
        }
        
        .progress-bar {
            height: 4px;
            background-color: var(--primary-color);
            width: 0%;
            transition: width 0.3s ease;
            border-radius: 2px;
            margin-top: 0.5rem;
        }
        
        /* Accessibility improvements */
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }
        
        /* Focus styles for accessibility */
        .btn:focus, .form-control:focus, .mode-btn:focus, .gender-btn:focus {
            outline: 2px solid var(--primary-color);
            outline-offset: 2px;
        }