.formula {
            font-family: 'Courier New', 'SF Mono', monospace;
            font-size: 1.1rem;
            background: #f1f3f5;
            padding: 0.3rem 0.6rem;
            border-radius: 6px;
        }
        .preset-btn-group {
            display: flex;
            flex-wrap: wrap;
            gap: 0.6rem;
            margin: 0.8rem 0;
        }
        .preset-btn {
            background: #f8f9fa;
            border: 1px solid #dee2e6;
            border-radius: 40px;
            padding: 0.3rem 0.9rem;
            font-size: 0.85rem;
            transition: all 0.2s;
            cursor: pointer;
        }
        .preset-btn:hover {
            background: #e9ecef;
            transform: translateY(-2px);
            border-color: #0d6efd;
        }
        .mode-selector {
            background: #eef2ff;
            border-radius: 48px;
            padding: 0.2rem;
            display: inline-flex;
        }
        .mode-btn {
            border: none;
            background: transparent;
            padding: 0.5rem 1.2rem;
            border-radius: 40px;
            font-weight: 500;
            transition: 0.2s;
        }
        .mode-btn.active {
            background: #0d6efd;
            color: white;
            box-shadow: 0 2px 6px rgba(13,110,253,0.3);
        }
        .canvas-chart {
            width: 100%;
            background: #ffffff;
            border-radius: 12px;
            border: 1px solid #e2e8f0;
            margin-top: 1rem;
        }
        .legend-inline {
            display: flex;
            gap: 1.5rem;
            justify-content: center;
            margin-top: 0.5rem;
            font-size: 0.8rem;
        }
        .badge-ref {
            background-color: #f1f5f9;
            color: #1e293b;
            font-weight: normal;
        }
        .unit-note {
            font-size: 0.85rem;
            color: #475569;
        }
        hr {
            margin: 1rem 0;
        }