MyBB Community Forums

I'm wondering how I can make a site like MyBB.com with MyBB?

By this I mean that the frontpage has information for what the site is about. Then there are other pages like "Features" "Docs" "Download" etc. Is there a particular plugin for this or is it natively built it? How would I style the pages to look good with minimal CSS knowledge?

These pages are not done with MyBB.

What CMS is it?

We used to use a custom CMS, the MyBB website is now hosted on Github pages. The Community Forums just has a custom theme to feel consistent.

Wouldn't it be nice to be able to build a somewhat similar site with Mybb?

MyBB is a forum engine, not a CMS, even if some plugins allows to add custom pages.
I think having an engine doing everything is a bad way, I prefer a good forum engine and a separate good CMS for other contents than only one engine who is bad on all its features.

BTW, having a look on CSS and HTML of non-forum pages can help doing a mybb-site-like.