body {
            background-color: #f8f9fa;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        .demo-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
        }
        
        .demo-header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 40px 20px;
            border-radius: 10px;
            margin-bottom: 30px;
            text-align: center;
        }
        
        .demo-section {
            background: white;
            border-radius: 10px;
            padding: 30px;
            margin-bottom: 20px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }
        
        .form-control, .form-select {
            border-radius: 8px;
            border: 2px solid #e9ecef;
            transition: border-color 0.3s ease;
        }
        
        .form-control:focus, .form-select:focus {
            border-color: #667eea;
            box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
        }
        
        .btn-primary {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            border: none;
            border-radius: 8px;
            padding: 12px 30px;
            font-weight: 600;
            transition: all 0.3s ease;
        }
        
        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
        }
        
        .output-container {
            background-color: #f8f9fa;
            border: 2px solid #e9ecef;
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
            min-height: 200px;
            font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
            font-size: 14px;
            white-space: pre-wrap;
            overflow-x: auto;
        }
        
        .loading {
            text-align: center;
            color: #6c757d;
            font-style: italic;
        }
        
        .error {
            color: #dc3545;
            background-color: #f8d7da;
            border: 1px solid #f5c6cb;
            border-radius: 5px;
            padding: 10px;
            margin-top: 10px;
        }
        
        .success {
            color: #155724;
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            border-radius: 5px;
            padding: 10px;
            margin-top: 10px;
        }
        
        .example-twee {
            background-color: #f1f3f4;
            border-left: 4px solid #667eea;
            padding: 15px;
            margin: 15px 0;
            border-radius: 0 8px 8px 0;
        }
        
        .format-info {
            background-color: #e7f3ff;
            border: 1px solid #b8daff;
            border-radius: 8px;
            padding: 15px;
            margin-top: 15px;
        }