Hi narendrakd,
I'm sorry but we can't help you to design website and forum, we support dozens of questions and problems every day, our time is very limited and it's not enough for helping in site specific customization.
I can say wpForo works fine with almost all themes, you should choose whatever you want. If you got some problem with some theme just let us know, we'll try to help you solve it.
We use premium WordPress theme, but there should be lots of other themes similar to ours. But I have not an exact list of theme names which may fit your needs.
i`m trying to do the same thing but dont understand which theme style.css you are talking bout , are you talking bout the website theme or do you mean the wp-foro theme ?
And where on that theme page do you paste that code ?
Sorry for beeing a NooB 🙁
I meant active theme stile.css file.
You can also put it in Dashboard > Forums > Settings > Styles > Custom CSS Code textarea. Save it, delete all cache and do Ctrl+F5 on forum front.