.input-group-custom {
            margin-bottom: 1rem;
        } 
        .deep-dive {
            margin: 1.8rem 0;
        }
        .deep-dive p {
            text-align: justify;
        }
        .unit-note {
            font-size: 0.9rem;
            color: #6c757d;
        }
        .coord-input {
            margin-bottom: 0.5rem;
        }
        .geometry-canvas {
            width: 100%;
            height: auto;
            background-color: #f9f9f9;
            border: 1px solid #ddd;
            border-radius: 8px;
            margin-top: 1.5rem;
            display: block;
        }
        .canvas-container {
            text-align: center;
            margin-top: 1rem;
        }
        .legend {
            display: flex;
            justify-content: center;
            gap: 2rem;
            margin: 0.5rem 0;
            font-size: 0.9rem;
            flex-wrap: wrap;
        }
        .legend-item {
            display: flex;
            align-items: center;
            gap: 0.3rem;
        }
        .legend-color {
            width: 16px;
            height: 16px;
            border-radius: 50%;
            display: inline-block;
        }
        .legend-color.green { background-color: #28a745; }
        .legend-color.blue { background-color: #0d6efd; }
        .legend-color.red { background-color: #dc3545; }
        .legend-color.purple { background-color: #9b59b6; }
        .legend-color.orange { background-color: #fd7e14; }
        .greek-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
            gap: 0.75rem;
            margin: 1rem 0;
        }
        .greek-card {
            background: #f8f9fa;
            border-radius: 6px;
            padding: 0.75rem 1rem;
            text-align: center;
            border: 1px solid #e9ecef;
        }
        .greek-card .symbol {
            font-size: 1.4rem;
            font-weight: 600;
            font-family: 'Cambria Math', serif;
        }
        .greek-card .value {
            font-size: 1.2rem;
            font-weight: 500;
            color: var(--primary-color);
        }
        .greek-card .label {
            font-size: 0.8rem;
            color: #6c757d;
        }
        .option-type-selector {
            display: flex;
            gap: 1rem;
            margin: 0.5rem 0 1rem 0;
        }
        .option-type-selector .form-check {
            margin-right: 1.5rem;
        }
        .result-section {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 1.5rem;
            margin-top: 1.5rem;
        }
        .highlight-price {
            font-size: 2.8rem;
            font-weight: 700;
            color: var(--primary-color);
        }
        .small-print {
            font-size: 0.8rem;
            color: #6c757d;
        }
        .formula-block {
            background: #ffffff;
            border: 1px solid #dee2e6;
            border-radius: 6px;
            padding: 1.2rem;
            margin: 1rem 0;
            font-family: 'Cambria Math', 'Latin Modern Math', serif;
            font-size: 1.15rem;
            text-align: center;
            overflow-x: auto;
        }
        .glossary-term {
            font-weight: 600;
            color: var(--accent-color);
        }
        .ref-list {
            columns: 2 280px;
            column-gap: 2rem;
            list-style: none;
            padding-left: 0;
        }
        .ref-list li {
            margin-bottom: 0.4rem;
            break-inside: avoid;
        }
        .ref-list li::before {
            content: "📘 ";
        }
        .sensitivity-table td, .sensitivity-table th {
            padding: 0.5rem;
            text-align: center;
        }
        @media (max-width: 768px) {
            .highlight-price {
                font-size: 2rem;
            }
            .greek-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }