.result-btu {
            font-size: 3.5rem;
            font-weight: 700;
            color: var(--primary-color, #0d6efd);
            line-height: 1.2;
        }
        .result-btu-label {
            font-size: 1.2rem;
            color: var(--text-muted, #6c757d);
        }
        .btu-range {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0.25rem 0;
        }
        .btu-range .range-bar {
            flex: 1;
            height: 8px;
            background: #e9ecef;
            border-radius: 4px;
            margin: 0 1rem;
            position: relative;
        }
        .btu-range .range-bar .fill {
            height: 100%;
            background: linear-gradient(90deg, #0d6efd, #0dcaf0);
            border-radius: 4px;
            transition: width 0.4s ease;
        }
        .btu-range .range-bar .marker {
            position: absolute;
            top: -6px;
            width: 18px;
            height: 18px;
            background: #dc3545;
            border: 2px solid #fff;
            border-radius: 50%;
            box-shadow: 0 0 8px rgba(220, 53, 69, 0.4);
            transform: translateX(-50%);
            transition: left 0.4s ease;
        }
        .btu-range .min-label,
        .btu-range .max-label {
            font-size: 0.8rem;
            color: var(--text-muted, #6c757d);
            white-space: nowrap;
        }
        .result-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
            gap: 1rem;
            margin: 1.5rem 0;
        }
        .result-grid .stat-card {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 1rem;
            text-align: center;
            border: 1px solid #e9ecef;
        }
        .result-grid .stat-card .stat-value {
            font-size: 1.6rem;
            font-weight: 600;
            color: var(--primary-color, #0d6efd);
        }
        .result-grid .stat-card .stat-label {
            font-size: 0.85rem;
            color: var(--text-muted, #6c757d);
        }
        .efficiency-badge {
            display: inline-block;
            padding: 0.4rem 1rem;
            border-radius: 30px;
            font-weight: 600;
            font-size: 0.9rem;
        }
        .efficiency-badge.excellent {
            background: #d1e7dd;
            color: #0f5132;
        }
        .efficiency-badge.good {
            background: #cfe2ff;
            color: #084298;
        }
        .efficiency-badge.fair {
            background: #fff3cd;
            color: #856404;
        }
        .efficiency-badge.poor {
            background: #f8d7da;
            color: #842029;
        }
        .factor-breakdown {
            margin: 1.5rem 0;
        }
        .factor-item {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            padding: 0.4rem 0;
            border-bottom: 1px solid #f0f0f0;
        }
        .factor-item .factor-label {
            width: 120px;
            font-weight: 500;
        }
        .factor-item .factor-bar {
            flex: 1;
            height: 6px;
            background: #e9ecef;
            border-radius: 3px;
            overflow: hidden;
        }
        .factor-item .factor-bar .factor-fill {
            height: 100%;
            border-radius: 3px;
            transition: width 0.6s ease;
        }
        .factor-item .factor-value {
            width: 60px;
            text-align: right;
            font-size: 0.9rem;
            color: var(--text-muted, #6c757d);
        }
        .preset-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin: 1rem 0;
        }
        .preset-btn {
            background: rgba(13, 110, 253, 0.08);
            border: 1px solid rgba(13, 110, 253, 0.2);
            border-radius: 30px;
            padding: 0.4rem 1rem;
            font-size: 0.85rem;
            color: var(--primary-color, #0d6efd);
            cursor: pointer;
            transition: all 0.2s;
        }
        .preset-btn:hover {
            background: rgba(13, 110, 253, 0.18);
            transform: translateY(-2px);
        }
        .chart-container.tall {
            height: 280px;
        }
        .disclaimer-box {
            font-size: 0.85rem;
            background: #f0f4f8;
            border-left: 4px solid var(--primary-color, #0d6efd);
            padding: 1rem 1.2rem;
            border-radius: 0 8px 8px 0;
            margin: 1.5rem 0;
        }
        .property-table th,
        .property-table td {
            padding: 0.75rem;
            text-align: left;
            border: 1px solid var(--border-color, #dee2e6);
        }
        .tool-header .lead {
            font-size: 1.1rem;
            font-weight: 400;
        }
        @media (max-width: 576px) {
            .result-btu {
                font-size: 2.5rem;
            }
            .result-grid {
                grid-template-columns: 1fr 1fr;
            }
            .factor-item .factor-label {
                width: 80px;
                font-size: 0.85rem;
            }
        }