ok lets see what can be said here.
The header + Navigation are big.. You can definitely improve that , and your header is not expanding accordingly , leaving a big black spot on the right side ! , which just seems like a waste of valuable space ( ULTRA VALUABLE on the header ) ...
The rest of the forums are "ok" Nothing impressive however , it can sure need a face-(forum)-lift , i would say , starting from header, working on to the forum views and topic views , with some more customization on the icons

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footer is good , i like it .
Regards