.preset-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 0.6rem;
            margin: 1rem 0;
        }
        .preset-btn {
            background: #f0f4f8;
            border: 1px solid #cbd5e1;
            border-radius: 40px;
            padding: 0.4rem 1rem;
            font-size: 0.85rem;
            font-weight: 500;
            transition: all 0.2s;
            color: #1e3a5f;
        }
        .preset-btn:hover {
            background: #e2e8f0;
            transform: translateY(-1px);
            border-color: #2c7da0;
        }
        .pie-container {
            background: #ffffff;
            border-radius: 12px;
            padding: 1rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
        }
        canvas#massPieCanvas {
            width: 100%;
            max-width: 280px;
            height: auto;
            background: #fefefe;
            margin: 0 auto;
            display: block;
        }
        .legend-pie {
            display: flex;
            justify-content: center;
            gap: 1.5rem;
            margin-top: 0.8rem;
            font-size: 0.85rem;
        }
        .legend-color-box {
            width: 14px;
            height: 14px;
            display: inline-block;
            border-radius: 2px;
            margin-right: 6px;
        }
        .result-card {
            background: #f8fafc;
            border-radius: 16px;
            padding: 1.2rem;
            margin-top: 1rem;
        }
        .input-group-custom {
            margin-bottom: 1rem;
        }
        .authority-badge {
            background: #ecfdf5;
            border-left: 3px solid #10b981;
            padding: 0.75rem 1rem;
            border-radius: 0.5rem;
        }
        .chemistry-fact {
            background: #fef9e3;
            border-radius: 12px;
            padding: 1rem;
            margin: 1rem 0;
        }
        .property-table td, .tooltip-custom {
            border-bottom: 1px dashed #6c757d;
            cursor: help;
        }