;
            return div.innerHTML;
        }
        
        // Event listeners
        document.getElementById('btn-run-all').addEventListener('click', runAllCells);
        document.getElementById('btn-restart-kernel').addEventListener('click', restartKernel);
        document.getElementById('btn-interrupt').addEventListener('click', interruptKernel);
        document.getElementById('btn-save').addEventListener('click', () => {
            console.log('Save functionality to be implemented');
        });