:root {
            --primary-color: #2c7da0;
            --secondary-color: #a9d6e5;
            --accent-color: #01497c;
            --light-gray: #f8f9fa;
            --border-color: #eaeaea;
            --text-color: #333;
            --text-muted: #6c757d;
            --success-color: #28a745;
            --warning-color: #ffc107;
            --spectroscopy-color: #2c7da0;
        }
         
        
        .page-header {
            background: linear-gradient(135deg, rgba(169, 214, 229, 0.4) 0%, rgba(44, 125, 160, 0.4) 100%);
            padding: 1.5rem 0;
            margin-bottom: 2rem;
            border-bottom: 1px solid rgba(44, 125, 160, 0.2);
            position: relative;
            overflow: hidden;     color: var(--text-color);
        }
  
        .breadcrumb {
            background-color: transparent;
            padding: 0.5rem 0;
            margin-bottom: 0.5rem;
        }
        
        .breadcrumb-item a {
            color: var(--text-muted);
            text-decoration: none;
        }
        
        .breadcrumb-item.active {
            color: var(--text-color);
        }
         
        
        /* IR Summary */
        .spectral-summary {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1.5rem;
            margin: 2rem 0;
        }
        
        .spectral-item {
            background: white;
            border-radius: 8px;
            padding: 1.5rem;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .spectral-item h4 {
            font-size: 1rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }
        
        .spectral-item .value {
            font-size: 1.5rem;
            font-weight: 700;
            color: var(--spectroscopy-color);
        }
        
        .spectral-item .detail {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
        }
        
        
        
        /* Spectrum examples */
        .spectrum-examples {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin-top: 1rem;
        }
        
        .spectrum-example {
            background-color: rgba(138, 43, 226, 0.1);
            border: 1px solid rgba(138, 43, 226, 0.2);
            border-radius: 4px;
            padding: 0.5rem 1rem;
            font-family: monospace;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .spectrum-example:hover {
            background-color: rgba(138, 43, 226, 0.2);
            transform: translateY(-2px);
        }
         
        /* Functional groups table */
        .functional-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.5rem 0;
        }
        
        .functional-table th, .functional-table td {
            padding: 0.75rem;
            text-align: left;
            border-bottom: 1px solid var(--border-color);
        }
        
        .functional-table th {
            background-color: var(--light-gray);
            font-weight: 600;
        }
        
        .functional-table tr:hover {
            background-color: rgba(138, 43, 226, 0.05);
        }
    
        /* Drawing canvas */
        .spectrum-canvas-container {
            position: relative;
            border: 1px solid #ddd;
            border-radius: 6px;
            margin: 1rem 0;
            overflow: hidden;
        }
        
        .spectrum-canvas {
            width: 100%;
            height: 300px;
            background-color: white;
            cursor: crosshair;
        }
        
        .canvas-controls {
            display: flex;
            justify-content: space-between;
            padding: 0.75rem;
            background-color: var(--light-gray);
            border-top: 1px solid #ddd;
        }
        
        .wavenumber-axis {
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            height: 30px;
            background-color: rgba(255,255,255,0.8);
            display: flex;
            justify-content: space-between;
            padding: 0 10px;
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        
        /* Upload area */
        .upload-area {
            border: 2px dashed #ddd;
            border-radius: 6px;
            padding: 2rem;
            text-align: center;
            margin: 1rem 0;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .upload-area:hover {
            border-color: var(--spectroscopy-color);
            background-color: rgba(138, 43, 226, 0.05);
        }
        
        .upload-area i {
            font-size: 3rem;
            color: var(--text-muted);
            margin-bottom: 1rem;
        }
        
        /* Peak identification */
        .peak-list {
            max-height: 300px;
            overflow-y: auto;
            margin: 1rem 0;
            border: 1px solid var(--border-color);
            border-radius: 6px;
        }
        
        .peak-item {
            padding: 0.75rem;
            border-bottom: 1px solid var(--border-color);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .peak-item:last-child {
            border-bottom: none;
        }
        
        .peak-wavenumber {
            font-weight: 600;
            color: var(--spectroscopy-color);
        }
        
        .peak-intensity {
            font-size: 0.9rem;
            color: var(--text-muted);
        }
        
        .peak-functional-group {
            font-size: 0.9rem;
            background-color: rgba(138, 43, 226, 0.1);
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
        }
        
        /* Enhanced features */
        .export-options {
            display: flex;
            gap: 0.5rem;
            margin-top: 1rem;
        }
        
        .compound-structure {
            text-align: center;
            margin: 1rem 0;
            padding: 1rem;
            background-color: white;
            border-radius: 6px;
            border: 1px solid var(--border-color);
        }
        
        .spectrum-comparison {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1rem;
            margin: 1.5rem 0;
        }
        
        @media (max-width: 768px) {
            .spectrum-comparison {
                grid-template-columns: 1fr;
            }
        }
        
        .enhancement-badge {
            position: absolute;
            top: 10px;
            right: 10px;
            background-color: #ffc107;
            color: #212529;
            padding: 0.25rem 0.5rem;
            border-radius: 4px;
            font-size: 0.75rem;
            font-weight: 600;
        }