* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #e4edf5 100%);
            color: #333;
            line-height: 1.6;
            padding: 20px;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
        }
        
        header {
            text-align: center;
            padding: 30px 20px;
            background: linear-gradient(90deg, #1a3a6c 0%, #2c5282 100%);
            color: white;
            border-radius: 10px 10px 0 0;
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
            margin-bottom: 30px;
        }
        
        header h1 {
            font-size: 2.8rem;
            margin-bottom: 15px;
            text-transform: uppercase;
            letter-spacing: 1.5px;
        }
        
        header .subtitle {
            font-size: 1.4rem;
            opacity: 0.9;
            font-weight: 300;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .news-meta {
            display: flex;
            justify-content: center;
            margin-top: 20px;
            font-size: 0.9rem;
            opacity: 0.8;
        }
        
        .news-meta span {
            margin: 0 15px;
        }
        
        .content-wrapper {
            display: flex;
            gap: 30px;
            margin-bottom: 40px;
        }
        
        .main-content {
            flex: 3;
            background: white;
            border-radius: 10px;
            padding: 30px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
        }
        
        .sidebar {
            flex: 1;
            background: white;
            border-radius: 10px;
            padding: 25px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            align-self: flex-start;
        }
        
        .section {
            margin-bottom: 40px;
        }
        
        .section h2 {
            color: #2c5282;
            font-size: 1.8rem;
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 2px solid #e2e8f0;
            display: flex;
            align-items: center;
        }
        
        .section h2 i {
            margin-right: 10px;
            color: #4299e1;
        }
        
        .highlight-box {
            background: #ebf8ff;
            border-left: 4px solid #4299e1;
            padding: 20px;
            margin: 20px 0;
            border-radius: 0 5px 5px 0;
        }
        
        .feature-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
            margin-top: 15px;
        }
        
        .feature-card {
            background: #f8fafc;
            border-radius: 8px;
            padding: 20px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.05);
            transition: transform 0.3s ease;
        }
        
        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        }
        
        .feature-card h3 {
            color: #2c5282;
            margin-bottom: 10px;
            display: flex;
            align-items: center;
        }
        
        .feature-card h3 i {
            margin-right: 10px;
            color: #4299e1;
        }
        
        .feature-card ul {
            padding-left: 20px;
        }
        
        .feature-card li {
            margin-bottom: 8px;
        }
        
        .application-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-top: 15px;
        }
        
        .application-card {
            background: #fff;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            padding: 20px;
            text-align: center;
            transition: all 0.3s ease;
        }
        
        .application-card:hover {
            border-color: #4299e1;
            box-shadow: 0 5px 15px rgba(66, 153, 225, 0.1);
        }
        
        .application-icon {
            font-size: 2.5rem;
            color: #2c5282;
            margin-bottom: 15px;
        }
        
        .application-card h3 {
            color: #2c5282;
            margin-bottom: 10px;
        }
        
        .chemical-structure {
            text-align: center;
            margin: 30px 0;
            padding: 20px;
            background: #f0f9ff;
            border-radius: 10px;
        }
        
        .chemical-structure h3 {
            color: #2c5282;
            margin-bottom: 15px;
        }
        
        .safety-section {
            background: #fffaf0;
            border-radius: 10px;
            padding: 25px;
            border-left: 4px solid #ecc94b;
            margin: 30px 0;
        }
        
        .safety-section h3 {
            color: #975a16;
            margin-bottom: 15px;
            display: flex;
            align-items: center;
        }
        
        .safety-section h3 i {
            margin-right: 10px;
        }
        
        .conclusion {
            background: #f0fff4;
            border-radius: 10px;
            padding: 25px;
            border-left: 4px solid #48bb78;
            margin-top: 30px;
            font-style: italic;
        }
        
        .conclusion p {
            font-size: 1.1rem;
            line-height: 1.7;
        }
        
        .sidebar h3 {
            color: #2c5282;
            margin-bottom: 20px;
            text-align: center;
            padding-bottom: 10px;
            border-bottom: 2px solid #e2e8f0;
        }
        
        .chemical-properties {
            margin-bottom: 30px;
        }
        
        .property {
            display: flex;
            justify-content: space-between;
            padding: 10px 0;
            border-bottom: 1px dashed #e2e8f0;
        }
        
        .property:last-child {
            border-bottom: none;
        }
        
        .property-name {
            font-weight: 600;
            color: #4a5568;
        }
        
        .property-value {
            color: #2c5282;
            font-weight: 500;
        }
        
        .decomposition-table {
            width: 100%;
            border-collapse: collapse;
            margin-top: 15px;
        }
        
        .decomposition-table th, 
        .decomposition-table td {
            padding: 10px;
            text-align: left;
            border-bottom: 1px solid #e2e8f0;
        }
        
        .decomposition-table th {
            background-color: #ebf8ff;
            color: #2c5282;
        }
        
        .decomposition-table tr:hover {
            background-color: #f7fafc;
        }
        
        footer {
            text-align: center;
            padding: 25px;
            background: #1a202c;
            color: #a0aec0;
            border-radius: 0 0 10px 10px;
            font-size: 0.9rem;
        }
        
        @media (max-width: 768px) {
            .content-wrapper {
                flex-direction: column;
            }
            
            header h1 {
                font-size: 2.2rem;
            }
            
            .feature-list {
                grid-template-columns: 1fr;
            }
        }
        /* Navigation Index Styles */
        .nav-index {
            background: white;
            border-radius: 8px;
            padding: 15px 25px;
            margin-bottom: 30px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.08);
            position: sticky;
            top: 20px;
            z-index: 100;
            border: 1px solid #e2e8f0;
        }
        
        .nav-index h3 {
            color: #2c5282;
            margin-bottom: 15px;
            display: flex;
            align-items: center;
            font-size: 1.3rem;
        }
        
        .nav-index h3 i {
            margin-right: 10px;
            color: #4299e1;
        }
        
        .index-links {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
        }
        
        .index-link {
            padding: 8px 15px;
            background: #f0f9ff;
            border-radius: 30px;
            text-decoration: none;
            color: #2c5282;
            font-size: 0.9rem;
            font-weight: 500;
            transition: all 0.3s ease;
            border: 1px solid #c5e3ff;
            display: flex;
            align-items: center;
        }
        
        .index-link i {
            margin-right: 8px;
            font-size: 0.8rem;
        }
        
        .index-link:hover {
            background: #4299e1;
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(66, 153, 225, 0.3);
        }