: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;
            --calculus-blue: #4a6fa5;
            --calculus-green: #3a7d34;
            --calculus-purple: #6f42c1;
        }
         
        .page-header {
            background: linear-gradient(135deg, rgba(169, 214, 229, 0.4) 0%, rgba(74, 111, 165, 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);
        }
         
        .calculus-info-box {
            background-color: rgba(111, 66, 193, 0.05);
            border-left: 3px solid var(--calculus-purple);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1.5rem 0;
        }
   
        /* 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(--calculus-blue);
            color: white;
        }
         
        .slider-value {
            background-color: var(--calculus-blue);
            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(74, 111, 165, 0.05);
        }
        
        /* Calculus-specific styling */
        .calculus-alert {
            background-color: rgba(111, 66, 193, 0.1);
            border-left: 4px solid var(--calculus-purple);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        .normal-range {
            color: var(--calculus-green);
            font-weight: 600;
        }
        
        .abnormal-range {
            color: #dc3545;
            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(74, 111, 165, 0.05);
        }
        
        .generating-indicator {
            display: none;
            text-align: center;
            padding: 1rem;
            color: var(--text-muted);
        }
        
        /* Function input styling */
        .function-input-group {
            display: flex;
            align-items: center;
            margin-bottom: 1rem;
        }
        
        .function-input {
            flex: 1;
            margin-right: 1rem;
        }
        
        .function-preview {
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 6px;
            padding: 0.75rem;
            margin: 1rem 0;
            font-family: 'Courier New', monospace;
            text-align: center;
        }
        
        .axis-toggle {
            display: flex;
            background-color: var(--light-gray);
            border-radius: 6px;
            padding: 4px;
            margin-bottom: 1.5rem;
        }
        
        .axis-btn {
            flex: 1;
            text-align: center;
            padding: 0.75rem;
            border-radius: 4px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
        }
        
        .axis-btn.active {
            background-color: var(--calculus-blue);
            color: white;
        }
        
        .formula-box {
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 6px;
            padding: 1rem;
            margin: 1rem 0;
            font-family: 'Courier New', monospace;
            text-align: center;
        }
        
        .math-expression {
            font-family: 'Cambria Math', 'Times New Roman', serif;
            font-size: 1.1rem;
        }
        
        .surface-area-visual {
            width: 100%;
            height: 200px;
            background-color: #f0f4f8;
            border-radius: 8px;
            margin: 1.5rem 0;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-muted);
            border: 1px dashed #dee2e6;
        }
        
        .example-box {
            background-color: rgba(74, 111, 165, 0.05);
            border-radius: 8px;
            padding: 1.5rem;
            margin: 1.5rem 0;
            border: 1px solid rgba(74, 111, 165, 0.2);
        }
        
        .example-title {
            font-weight: 600;
            color: var(--calculus-blue);
            margin-bottom: 0.75rem;
        }
        
        .integral-symbol {
            font-size: 1.5rem;
            vertical-align: middle;
            margin: 0 0.25rem;
        }
        
        .variable-input {
            width: 80px;
        }
        
        .calculus-chart-container {
            position: relative;
            height: 300px;
            width: 100%;
            margin: 1.5rem 0;
        }
        
        .example-btn {
            background-color: rgba(74, 111, 165, 0.1);
            color: var(--calculus-blue);
            border: 1px solid rgba(74, 111, 165, 0.3);
            border-radius: 4px;
            padding: 0.25rem 0.5rem;
            margin: 0.25rem;
            font-size: 0.9rem;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .example-btn:hover {
            background-color: rgba(74, 111, 165, 0.2);
        }
        
        .derivative-note {
            background-color: rgba(58, 125, 52, 0.05);
            border-left: 3px solid var(--calculus-green);
            padding: 1rem;
            border-radius: 0 4px 4px 0;
            margin: 1rem 0;
        }
        
        .coordinate-system {
            position: relative;
            width: 100%;
            height: 200px;
            border-left: 2px solid #333;
            border-bottom: 2px solid #333;
            margin: 1.5rem 0;
            background-color: #f8f9fa;
        }
        
        .axis-label {
            position: absolute;
            font-weight: 600;
        }
        
        .x-axis-label {
            bottom: -25px;
            right: 10px;
        }
        
        .y-axis-label {
            top: 10px;
            left: -25px;
        }
        
        .function-graph {
            position: absolute;
            width: 100%;
            height: 100%;
        }
        
        /* Symbolic math styling */
        .symbolic-result {
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 6px;
            padding: 1rem;
            margin: 1rem 0;
            font-family: 'Cambria Math', 'Times New Roman', serif;
            font-size: 1.1rem;
        }
        
        .symbolic-step {
            margin: 0.5rem 0;
            padding: 0.5rem;
            border-left: 2px solid var(--calculus-purple);
            background-color: rgba(111, 66, 193, 0.05);
        }
        
        .calculation-step {
            margin: 1rem 0;
            padding: 1rem;
            border-radius: 6px;
            background-color: #f8f9fa;
            border: 1px solid #dee2e6;
        }
        
        .symbolic-error {
            background-color: rgba(220, 53, 69, 0.1);
            border-left: 3px solid #dc3545;
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }
        
        .symbolic-success {
            background-color: rgba(40, 167, 69, 0.1);
            border-left: 3px solid var(--calculus-green);
            padding: 1rem;
            margin: 1rem 0;
            border-radius: 0 4px 4px 0;
        }