Thanks once again for helping.
I went back and tried to edit the h2 value, but that didn’t change anything. Then I saw this in the css:
It’s used in the page here:
The font size relates to the navigation text. So the text in the menu is 13px, but this styling spills over into the forum. So all the text in the forum is 13px too.
I then deleted fs3 from the css to see what would happen, and sure enough the text size in the forum went back to normal, but of course the navigation text became too small.
I tried to add fs4 (with a smaller font size) just above the forum in the html, but it has no effect, fs3 still dominates. So I think it just comes down to this…need to stop fs3 being expressed in the forum area. But don’t know how :(