.method-card {
            background: #f9fafc;
            border-radius: 12px;
            padding: 1.2rem;
            margin-bottom: 1.5rem;
            border: 1px solid #e2e8f0;
            transition: 0.2s;
            position: relative;
        }
        .method-card:hover {
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
        }
        .period-badge {
            font-size: 2rem;
            font-weight: 700;
            color: #0d6efd;
            font-family: monospace;
        }
        .wave-canvas {
            width: 100%;
            background: #fefefe;
            border-radius: 12px;
            border: 1px solid #dee2e6;
            margin-top: 20px;
        }
        .legend {
            display: flex;
            justify-content: center;
            gap: 1.5rem;
            margin-top: 10px;
        }
        .legend-color {
            width: 18px;
            height: 18px;
            display: inline-block;
            border-radius: 2px;
        }
        .warning-tooltip {
            font-size: 0.75rem;
            color: #b85c00;
            background: #fff3e0;
            border-radius: 12px;
            padding: 0.2rem 0.5rem;
            display: inline-block;
            margin-top: 0.5rem;
        }