:root {
            --primary-color: #e75480;
            --secondary-color: #f8c8dc;
            --accent-color: #c2185b;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --success-color: #28a745;
            --warning-color: #ffc107;
            --pregnancy-pink: #e75480;
            --pregnancy-purple: #9c27b0;
            --pregnancy-blue: #2196f3;
            --pregnancy-green: #4caf50;
            --pregnancy-orange: #ff9800;
            --pregnancy-teal: #009688;
        }
        
        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(--pregnancy-pink);
            font-size: 1.5rem;
        }
        
        .nav-link {
            color: #555;
            font-weight: 500;
            padding: 0.5rem 1rem;
            border-radius: 6px;
        }
        
        .nav-link:hover, .nav-link.active {
            color: var(--pregnancy-pink);
            background-color: rgba(231, 84, 128, 0.1);
        }
        
        .page-header {
            background: linear-gradient(135deg, rgba(248, 200, 220, 0.4) 0%, rgba(231, 84, 128, 0.4) 100%);
            padding: 1.5rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(231, 84, 128, 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 10px rgba(0,0,0,0.05);
        }
        
        .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(--pregnancy-pink);
            margin-bottom: 0.5rem;
        }
        
        /* Form Styles */
        .form-label {
            font-weight: 600;
            margin-bottom: 0.5rem;
            color: var(--text-color);
        }
        
        .form-control {
            border: 1px solid #ddd;
            border-radius: 6px;
            padding: 0.75rem;
            transition: all 0.3s;
        }
        
        .form-control:focus {
            border-color: var(--pregnancy-pink);
            box-shadow: 0 0 0 3px rgba(231, 84, 128, 0.15);
        }
        
        .input-group-text {
            background-color: var(--light-gray);
            border: 1px solid #ddd;
        }
        
        .btn-primary {
            background-color: var(--pregnancy-pink);
            border-color: var(--pregnancy-pink);
            font-weight: 600;
            padding: 0.75rem 1.5rem;
            border-radius: 6px;
            transition: all 0.3s;
        }
        
        .btn-primary:hover {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            transform: translateY(-1px);
        }
        
        .btn-outline-secondary {
            font-weight: 600;
            border-radius: 6px;
            padding: 0.75rem 1.5rem;
        }
        
        /* Result Area */
        .result-container {
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 1.5rem;
            margin-top: 1.5rem;
            position: relative;
            border: 1px solid var(--border-color);
        }
        
        .result-title {
            font-weight: 600;
            margin-bottom: 0.75rem;
            color: var(--pregnancy-pink);
        }
        
        .result-content {
            word-break: break-all;
            padding: 12px;
            background-color: white;
            border-radius: 4px;
            border: 1px solid #eee;
            font-size: 0.95rem;
        }
        
        .summary-card {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .summary-value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--pregnancy-pink);
            margin-bottom: 0.5rem;
        }
        
        .summary-label {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        /* Chart Container */
        .chart-container {
            position: relative;
            height: 400px;
            width: 100%;
            margin: 2rem 0;
        }
        
        /* Pregnancy Summary */
        .pregnancy-summary {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        
        .pregnancy-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);
        }
        
        .pregnancy-item h4 {
            font-size: 1rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        
        .pregnancy-item .value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--pregnancy-pink);
        }
        
        .pregnancy-item .detail {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
        
        /* Content Sections */
        .section-title {
            font-weight: 600;
            margin-bottom: 1rem;
            color: var(--pregnancy-pink);
            padding-bottom: 0.5rem;
            border-bottom: 1px solid var(--border-color);
        }
        
        .usage-step {
            display: flex;
            margin-bottom: 1.5rem;
            align-items: flex-start;
        }
        
        .step-number {
            width: 28px;
            height: 28px;
            background-color: var(--pregnancy-pink);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 1rem;
            flex-shrink: 0;
            font-weight: 600;
            font-size: 0.9rem;
        }
        
        .info-box {
            background-color: rgba(231, 84, 128, 0.05);
            border-left: 3px solid var(--pregnancy-pink);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        
        .medical-info-box {
            background-color: rgba(33, 150, 243, 0.05);
            border-left: 3px solid var(--pregnancy-blue);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
        
        /* Related Tools */
        .related-tools {
            background-color: white;
            border-radius: 8px;
            border: 1px solid var(--border-color); 
            margin-bottom: 1.5rem;
        }
        
        .related-title {
            font-weight: 600;
            margin-bottom: 1.25rem;
            padding-bottom: 0.75rem; 
            color: var(--pregnancy-pink);
        }
        
        .related-tool {
            display: flex;
            align-items: center;
            padding: 0.75rem 0;
            border-bottom: 1px solid var(--border-color);
            transition: background-color 0.3s;
        }
        
        .related-tool:hover {
            background-color: var(--light-gray);
        }
        
        .related-tool:last-child {
            border-bottom: none;
        }
        
        .related-icon {
            width: 36px;
            height: 36px;
            border-radius: 6px;
            background-color: rgba(231, 84, 128, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 1rem;
            color: var(--pregnancy-pink);
        }
        
        .related-name {
            font-weight: 500;
            margin-bottom: 0.25rem;
        }
        
        .related-desc {
            color: var(--text-muted);
            font-size: 0.9rem;
        }
        
        /* Ad Container */
        .ad-container {
            background-color: var(--light-gray);
            border-radius: 8px;
            padding: 1.5rem;
            margin-bottom: 1.5rem;
            text-align: center;
            border: 1px solid var(--border-color);
        }
        
        .ad-label {
            font-size: 0.75rem;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 1px;
            margin-bottom: 0.5rem;
        }
        
        .ad-placeholder {
            width: 100%;
            height: 250px;
            background-color: #f0f4f8;
            border: 1px dashed #dee2e6;
            border-radius: 6px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-muted);
            font-weight: 500;
        }
        
        /* Footer */
        .footer {
            background-color: var(--light-gray); 
            margin-top: 3rem;
            border-top: 1px solid var(--border-color);
        }
        
        /* Responsive Adjustments */
        @media (max-width: 768px) {
            .tool-card {
                padding: 1.5rem;
            }
            
            .pregnancy-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(--pregnancy-pink);
            color: white;
        }
        
        /* Toast notifications */
        .toast-container {
            position: fixed;
            bottom: 20px;
            right: 20px;
            z-index: 1050;
        }
        
        /* Action buttons */
        .action-btn {
            background-color: white;
            border: 1px solid var(--border-color);
            border-radius: 6px;
            padding: 0.5rem 1rem;
            margin-left: 0.5rem;
            transition: all 0.3s;
            color: var(--text-color);
        }
        
        .action-btn:hover {
            background-color: var(--light-gray);
            color: var(--pregnancy-pink);
        }
        
        /* Range slider styling */
        .form-range {
            width: 100%;
            height: 1rem;
            padding: 0;
            background-color: transparent;
            -webkit-appearance: none;
        }
        
        .form-range:focus {
            outline: none;
        }
        
        .form-range::-webkit-slider-thumb {
            width: 1rem;
            height: 1rem;
            margin-top: -0.5rem;
            background-color: var(--pregnancy-pink);
            border: 0;
            border-radius: 1rem;
            -webkit-appearance: none;
        }
        
        .form-range::-webkit-slider-runnable-track {
            width: 100%;
            height: 0.5rem;
            cursor: pointer;
            animate: 0.2s;
            background: var(--light-gray);
            border-radius: 0.5rem;
        }
        
        .slider-value {
            background-color: var(--pregnancy-pink);
            color: white;
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
            font-size: 0.8rem;
            margin-left: 0.5rem;
        }
        
        /* Input group styling */
        .input-group {
            margin-bottom: 1rem;
        }
        
        /* 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(231, 84, 128, 0.05);
        }
        
        /* Pregnancy-specific styling */
        .pregnancy-alert {
            background-color: rgba(33, 150, 243, 0.1);
            border-left: 4px solid var(--pregnancy-blue);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        .normal-range {
            color: var(--pregnancy-green);
            font-weight: 600;
        }
        
        .abnormal-range {
            color: var(--pregnancy-pink);
            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(231, 84, 128, 0.05);
        }
        
        .generating-indicator {
            display: none;
            text-align: center;
            padding: 1rem;
            color: var(--text-muted);
        }
        
        /* Pregnancy specific styles */
        .pregnancy-input-group {
            display: flex;
            align-items: center;
            margin-bottom: 1rem;
        }
        
        .pregnancy-input {
            width: 120px;
            margin-right: 1rem;
        }
        
        .pregnancy-separator {
            font-size: 1.5rem;
            font-weight: bold;
            color: var(--text-muted);
            margin: 0 0.5rem;
        }
        
        .pregnancy-classification {
            padding: 1rem;
            border-radius: 8px;
            margin: 1rem 0;
            border-left: 5px solid;
        }
        
        .pregnancy-trimester1 {
            background-color: rgba(231, 84, 128, 0.1);
            border-left-color: var(--pregnancy-pink);
        }
        
        .pregnancy-trimester2 {
            background-color: rgba(33, 150, 243, 0.1);
            border-left-color: var(--pregnancy-blue);
        }
        
        .pregnancy-trimester3 {
            background-color: rgba(76, 175, 80, 0.1);
            border-left-color: var(--pregnancy-green);
        }
        
        .pregnancy-chart-container {
            position: relative;
            height: 300px;
            width: 100%;
            margin: 1.5rem 0;
        }
        
        .pregnancy-status-indicator {
            display: inline-block;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            margin-right: 8px;
        }
        
        .status-trimester1 {
            background-color: var(--pregnancy-pink);
        }
        
        .status-trimester2 {
            background-color: var(--pregnancy-blue);
        }
        
        .status-trimester3 {
            background-color: var(--pregnancy-green);
        }
        
        /* Week tracker styles */
        .week-tracker {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            margin: 1.5rem 0;
        }
        
        .week-item {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s;
            background-color: #f0f0f0;
            color: #666;
        }
        
        .week-item:hover {
            transform: scale(1.1);
        }
        
        .week-item.current {
            background-color: var(--pregnancy-pink);
            color: white;
            transform: scale(1.1);
            box-shadow: 0 4px 8px rgba(231, 84, 128, 0.3);
        }
        
        .week-item.past {
            background-color: var(--pregnancy-blue);
            color: white;
        }
        
        .week-item.future {
            background-color: #f0f0f0;
            color: #999;
        }
        
        /* Development info styles */
        .development-info {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
        }
        
        .development-image {
            width: 100%;
            max-width: 300px;
            height: auto;
            border-radius: 8px;
            margin: 1rem 0;
            display: block;
            background-color: #f5f5f5;
            border: 1px solid #eee;
        }
        
        .symptom-list {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        .symptom-item {
            background-color: rgba(231, 84, 128, 0.05);
            padding: 1rem;
            border-radius: 6px;
            border-left: 3px solid var(--pregnancy-pink);
        }
        
        .symptom-item h5 {
            color: var(--pregnancy-pink);
            margin-bottom: 0.5rem;
            font-size: 1rem;
        }
        
        /* Timeline styles */
        .timeline {
            position: relative;
            max-width: 800px;
            margin: 2rem auto;
        }
        
        .timeline::after {
            content: '';
            position: absolute;
            width: 4px;
            background-color: var(--pregnancy-pink);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -2px;
        }
        
        .timeline-item {
            padding: 10px 40px;
            position: relative;
            background-color: inherit;
            width: 50%;
            box-sizing: border-box;
        }
        
        .timeline-item::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            right: -10px;
            background-color: white;
            border: 4px solid var(--pregnancy-pink);
            top: 15px;
            border-radius: 50%;
            z-index: 1;
        }
        
        .left {
            left: 0;
        }
        
        .right {
            left: 50%;
        }
        
        .right::after {
            left: -10px;
        }
        
        .timeline-content {
            padding: 20px;
            background-color: white;
            position: relative;
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        
        @media screen and (max-width: 768px) {
            .timeline::after {
                left: 31px;
            }
            
            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }
            
            .timeline-item::after {
                left: 21px;
            }
            
            .right {
                left: 0%;
            }
        }
        
        /* Accessibility improvements */
        .sr-only {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0,0,0,0);
            border: 0;
        }
        
        /* Loading animation improvements */
        .loading-overlay {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: rgba(255,255,255,0.8);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 1000;
            border-radius: 8px;
        }
        
        .spinner {
            width: 40px;
            height: 40px;
            border: 4px solid rgba(231, 84, 128, 0.1);
            border-radius: 50%;
            border-top-color: var(--pregnancy-pink);
            animation: spin 1s ease-in-out infinite;
        }
        
        @keyframes spin {
            to { transform: rotate(360deg); }
        }
        
        /* High risk pregnancy warning */
        .high-risk-warning {
            background-color: rgba(255, 193, 7, 0.15);
            border-left: 4px solid var(--warning-color);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        /* Multiple pregnancy styling */
        .multiple-pregnancy {
            background-color: rgba(156, 39, 176, 0.1);
            border-left: 4px solid var(--pregnancy-purple);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        /* Ultrasound adjustment styling */
        .ultrasound-adjustment {
            background-color: rgba(0, 150, 136, 0.1);
            border-left: 4px solid var(--pregnancy-teal);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        /* Personalization section */
        .personalization-section {
            background-color: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
        }
        
        /* Print styles */
        @media print {
            .navbar, .page-header, .related-tools, .ad-container, .footer, .action-btn, .btn {
                display: none !important;
            }
            
            .tool-card, .result-container {
                box-shadow: none;
                border: 1px solid #ddd;
            }
            
            body {
                background-color: white;
                font-size: 12pt;
            }
            
            .container {
                max-width: 100%;
            }
        }
        
        /* Dark mode support */
        @media (prefers-color-scheme: dark) {
            body {
                background-color: #121212;
                color: #e0e0e0;
            }
            
            .tool-card, .related-tools, .personalization-section {
                background-color: #1e1e1e;
                border-color: #333;
            }
            
            .form-control {
                background-color: #2d2d2d;
                border-color: #444;
                color: #e0e0e0;
            }
            
            .form-control:focus {
                background-color: #2d2d2d;
                border-color: var(--pregnancy-pink);
                color: #e0e0e0;
            }
            
            .result-container {
                background-color: #1a1a1a;
            }
        }