#2 Apr 27, 2017 20:49
Don't worry - found the answer. Dead easy when you look! Simply chose the Collection, then went into Skin/Layout/Layout Settings, chose the appropriate Column size and everything changes like magic!
The lesson I learned here is that although I am used to working in CSS, I should trust the b2evolution techies to have built a simple solution into the package instead of automatically looking for a stylesheet to change. Thanks guys.