.mode-selector {
            margin-bottom: 1.5rem;
            border-bottom: 2px solid #e9ecef;
            padding-bottom: 0.5rem;
        }
        .mode-btn {
            margin-right: 1rem;
            padding: 0.5rem 1.2rem;
            font-weight: 500;
            border-radius: 30px;
            transition: all 0.2s;
        }
        .mode-btn.active {
            background-color: var(--primary-color, #0d6efd);
            color: white;
        }
        .formula-card {
            background: #f1f8ff;
            border-radius: 16px;
            padding: 1rem;
            margin: 1rem 0;
            font-family: 'Courier New', monospace;
        }
        .result-highlight {
            font-size: 2.2rem;
            font-weight: 700;
            color: #0d6efd;
        }
        .unit-note {
            font-size: 0.85rem;
            color: #6c757d;
        }
        .graph-container {
            background: #ffffff;
            border-radius: 16px;
            padding: 1rem;
            margin-top: 1rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }
        .legend-color {
            width: 16px;
            height: 16px;
            border-radius: 50%;
            display: inline-block;
        }
        .legend-color.emf { background-color: #dc3545; }
        .legend-color.voltage { background-color: #198754; }