Can't say that I can help with your particular problem, but perhaps the thread I just started can help you identify a method you can use to figure this out. The assumption, of course, is that you have a basic understanding of HTML/CSS.
https://vborg.vbsupport.ru/showthread.php?t=240269
Get Firefox and the "Web Developer" add-on. With it you can inspect the on-screen elements and identify the CSS that you might want to study for changes.
-Martin