XF 1.3 Membercard Width

Hey Guys.

This i'm hoping is really simple to find and edit, but I think I'm being silly and can't find it.

So I've just added new ranks for each of my user groups which went well and worked fine, however I notice when looking through threads the images are a little bit big an therefore go over the edge of the membercard (I think this is what it is called, it is the part to the left of the post that holds a users info) edges. I am looking to work out which part of coding/CSS I need to edit to increase the width of it.
Unfortunately that did not appear to help.

The part circled in red is what is causing the problem. So my first question is 1) Is there a way to centre that image? 2) How do it edit the width of the part circled in green?