Auto complete not working as expected

I’m new to Atom 2 and I’m also not an experienced developer (I can’t even consider myself a developer, but…).
I’ve been working with Brackets and now transitioning to Atom I’ve noticed that it doesn’t auto complete the same way as Brackets does:
1 - I have a CSS file linked to my document and even though I have a “btn” class, when I type “btn” it doesn’t auto suggest it
2 - When I type “btn” it shows me all options that contain those letters, separately. What I mean is that it’s showing me classes that contain a “b”, classes that contain a “t” and classes that contain an “n”.

Am I missing anything here? Doesn’t seem very intuitive and makes no sense that it works this way.

Any help is appreciated! :slight_smile:Thanks!