execution-count').textContent = execCount;
            
            try {
                const response = await fetch('/api/execute', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        cell_id: cellId,
                        code: code,
                        execution_count: execCount
                    })
                });
                
                const result = await re