There are a few issues with the mobile/responsive version of CF I would like to talk about.
First, the mobile CF doesn't use the whole screen. You know, the mobile devices have small screens, and not using all this small space is a bit of a problem and it looks not that good. The forum have to expand and use every valuable pixel.
Second, the categories have to be removed from the frontpage (mobile only). Imagine you have a forum with hundreds of categories and the user has to scroll.....scroll....and scroll....and than can see the recent topics. The categories could go into that menu button on the NavBar.
Third, the topic title, when you are inside the topic is there twice. First on the linktree and than again on the top of the topic. I think, when you are inside the topic you don't need to click the title of the topic again. It makes no sense and takes again valuable space.
And, that search bar is ugly. Codoforum is a beautiful forum, but the search bar is a no-go. It is ugly and takes a lot of space. It have to be replaced with a nice buton or a small search field on the top. Right into the NavBar. Like the modern websites do now.
PS: An autosave thing is very welcome here. I closed the tab when writing the post and had to write it again. ;)