child styles

I am a WordPress user who is soon going to migrate his blog to Xenforo as a CMS. In WordPress, we have child themes for any kind of custom CSS, fonts, or snippets so that we don't lose changes when the parent theme or core is updated. Does Xenforo have similar functionality?

I have made a bunch of style changes, and have my forum looking pretty much the way I want. Now I have learned that it is better to first create a child style before making customizations. Is there a way i can move my customizations to a child style without losing them? Thanks in advance.