How to centre row content?

[hoohum]

I have a php mysql site which has an admin page showing three drop downs. In each of the drop downs a product can be selected from a list. Once the admin page is saved, those 3 products are displayed on the home page in a 'featured products' row. The code to display them is set using the class 4u. So perfect, 3 product photos show side by side, or underneath each other on smartphones.

Only problem is, the administrator can just select two products and leave one blank. So the resulting display is two thumbnails aligned left on the page with a gap on the right.

I would like to centre the display if only one or two products are selected to make even gaps either side. I cannot do that.

Can the contents of a row with cells set with 4u class, be centre aligned somehow, or can some code be written that intelligently assigns 12u if one product is presented, 6u if two are presented and 4u if three are presented?

[morvy]

you can use offsets, so you need to calculate, if 3 items, offset 0, if 2 items, offset 2, if 1 item, offset 4 ..