Resizing dropdowns (and other form elements)

[Ryan Nash]

I have quite a wide inline form, which I want to keep in a single line because it creates a record which fills a single row on a table.

I'd like to shrink things a bit. I know that mini, small, medium etc. exist for most form elements like inputs, but what about dropdown boxes?
Can they be manually sized with CSS to match the size of the other inputs?

Also, I'm getting slightly buggy behaviour where the fields overlap (not visually but with padding) and cut off each others boarders, until you click one, then it sort of gets brought to the front with all it's boarders visible.