* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            padding: 20px;
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            background: rgba(255, 255, 255, 0.95);
            border-radius: 20px;
            padding: 30px;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
            backdrop-filter: blur(10px);
        }
        
        .header {
            text-align: center;
            margin-bottom: 40px;
            padding-bottom: 20px;
            border-bottom: 3px solid #667eea;
        }
        
        .header h1 {
            color: #2d3748;
            font-size: 2.5rem;
            margin-bottom: 10px;
            font-weight: 700;
        }
        
        .header p {
            color: #4a5568;
            font-size: 1.2rem;
            margin-bottom: 5px;
        }
        
        .subtitle {
            color: #667eea;
            font-weight: 600;
            font-size: 1.1rem;
        }
        
        .erd-container {
            display: flex;
            flex-direction: column;
            gap: 30px;
            margin-bottom: 40px;
        }
        
        .diagram-section {
            background: white;
            border-radius: 15px;
            padding: 25px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
            border: 2px solid #e2e8f0;
        }
        
        .section-title {
            color: #2d3748;
            font-size: 1.5rem;
            margin-bottom: 20px;
            font-weight: 600;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .icon {
            width: 24px;
            height: 24px;
            background: #667eea;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: bold;
            font-size: 14px;
        }
        
        .tables-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 25px;
            margin-bottom: 30px;
        }
        
        .table-entity {
            background: linear-gradient(145deg, #f7fafc, #edf2f7);
            border-radius: 12px;
            border: 2px solid #cbd5e0;
            overflow: hidden;
            transition: all 0.3s ease;
            position: relative;
        }
        
        .table-entity:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 35px rgba(102, 126, 234, 0.15);
            border-color: #667eea;
        }
        
        .table-header {
            background: linear-gradient(135deg, #667eea, #764ba2);
            color: white;
            padding: 15px;
            font-weight: 700;
            font-size: 1.1rem;
            text-align: center;
            position: relative;
        }
        
        .table-header::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 0;
            border-left: 10px solid transparent;
            border-right: 10px solid transparent;
            border-top: 10px solid #764ba2;
        }
        
        .table-fields {
            padding: 0;
        }
        
        .field-row {
            display: flex;
            align-items: center;
            padding: 12px 15px;
            border-bottom: 1px solid #e2e8f0;
            transition: background-color 0.2s ease;
        }
        
        .field-row:hover {
            background-color: rgba(102, 126, 234, 0.05);
        }
        
        .field-row:last-child {
            border-bottom: none;
        }
        
        .field-name {
            font-weight: 600;
            color: #2d3748;
            flex: 1;
            font-size: 0.95rem;
        }
        
        .field-type {
            color: #4a5568;
            font-size: 0.85rem;
            background: #f1f5f9;
            padding: 4px 8px;
            border-radius: 6px;
            margin-left: 10px;
        }
        
        .pk {
            background: linear-gradient(135deg, #f093fb, #f5576c);
            color: white;
        }
        
        .fk {
            background: linear-gradient(135deg, #4facfe, #00f2fe);
            color: white;
        }
        
        .key-indicator {
            width: 8px;
            height: 8px;
            border-radius: 50%;
            margin-right: 8px;
            flex-shrink: 0;
        }
        
        .pk-indicator {
            background: linear-gradient(135deg, #f093fb, #f5576c);
            box-shadow: 0 0 10px rgba(240, 147, 251, 0.5);
        }
        
        .fk-indicator {
            background: linear-gradient(135deg, #4facfe, #00f2fe);
            box-shadow: 0 0 10px rgba(79, 172, 254, 0.5);
        }
        
        .relationships-container {
            background: white;
            border-radius: 15px;
            padding: 25px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
            border: 2px solid #e2e8f0;
        }
        
        .relationship-item {
            display: flex;
            align-items: center;
            padding: 15px;
            margin-bottom: 15px;
            background: linear-gradient(135deg, #f8fafc, #f1f5f9);
            border-radius: 10px;
            border-left: 4px solid #667eea;
            transition: all 0.3s ease;
        }
        
        .relationship-item:hover {
            background: linear-gradient(135deg, #edf2f7, #e2e8f0);
            transform: translateX(5px);
        }
        
        .relationship-text {
            color: #2d3748;
            font-weight: 500;
            flex: 1;
        }
        
        .cardinality {
            background: linear-gradient(135deg, #667eea, #764ba2);
            color: white;
            padding: 6px 12px;
            border-radius: 20px;
            font-size: 0.85rem;
            font-weight: 600;
            margin-left: 15px;
        }
        
        .legend {
            display: flex;
            justify-content: center;
            gap: 30px;
            margin-top: 30px;
            padding: 20px;
            background: linear-gradient(135deg, #f8fafc, #f1f5f9);
            border-radius: 12px;
            border: 1px solid #e2e8f0;
        }
        
        .legend-item {
            display: flex;
            align-items: center;
            gap: 8px;
            font-weight: 500;
            color: #2d3748;
        }
        
        .business-rules {
            background: white;
            border-radius: 15px;
            padding: 25px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
            border: 2px solid #e2e8f0;
            margin-top: 30px;
        }
        
        .rules-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 20px;
        }
        
        .rule-category {
            background: linear-gradient(135deg, #f8fafc, #f1f5f9);
            border-radius: 10px;
            padding: 20px;
            border-left: 4px solid #667eea;
        }
        
        .rule-category h4 {
            color: #2d3748;
            margin-bottom: 15px;
            font-size: 1.1rem;
            font-weight: 600;
        }
        
        .rule-list {
            list-style: none;
        }
        
        .rule-list li {
            color: #4a5568;
            margin-bottom: 8px;
            padding-left: 15px;
            position: relative;
            font-size: 0.95rem;
        }
        
        .rule-list li::before {
            content: '✓';
            position: absolute;
            left: 0;
            color: #667eea;
            font-weight: bold;
        }
        
        @media (max-width: 768px) {
            .tables-grid {
                grid-template-columns: 1fr;
            }
            
            .legend {
                flex-direction: column;
                gap: 15px;
            }
            
            .header h1 {
                font-size: 2rem;
            }
        }