透明桌边界有tr背景

I use :nth-child(odd/even) selector to make different background for table rows for better readability. And now I have to set "border-spacing" or "border-color: transparent" for my table, to make background visible thru the space between cells. The problem is, that horizontal spacing should be different for different columns - the last column should have larger spacing than whole table (marked with red in the sample below). How can I do that? Have no idea. Please help. Thank you!I use :nth-child(odd/even) selector to make dif