n selectCell(cellId) {
            document.querySelectorAll('.cell').forEach(c => c.classList.remove('selected'));
            const cell = document.querySelector(`[data-cell-id="${cellId}"]`);
            if (cell) {
                cell.classList.add('selected');
                currentCellId = cellId;
                cell.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
            }
        }
        
        function selectNextCell(cellId) {
            const cell = document.querySelector(`[d