Casper Navigation hiding on scroll?

Maybe I’m missing something, but when I installed Ghost and I selected Casper for my site, I was under the impression that the nav will hide and the post title will be shown instead when the reader scrolls through the page, just like it happens in the “Select Theme” section on the editor.

On scroll, it hides and shows the post title:

But in reality that never happens. The classes to make that work are present online in error.hbs, not in default.hbs.



On top of that, I can’t find sticky-nav-title.js anywhere on my assets folder.

So I’m a bit confused here. Why there are two different codes for the navigation? And how do I make the default “hide navigation on scroll” work?