Which files need to be edited to change the category layout and thumbnail sizes?

As much as I try to figure out how to change the thumbnail size on any category webpage, I can’t figure out where to change this. I want to change where they are positioned on the page, their size, and add a white border around them.

I’ve tried changing the thumbnail size in functions.php, modifying the style.css, modifying category.php, and the various associated loop.php and loop-xxx.php files. Are there any other files I should be looking at?

Thanks!
– Ada

• This topic was modified 12 years, 9 months ago by ako.