How do you customize the login/sign-up page layout?

I'm going crazy! How do I change the layout for the login/signup pages? I tried adding a sessions_controller.rb and defining it there, but it didn't change.

Not sure if this is what you wanted but most of the code for those pages is in these files:

App layout: app/views/layouts/application.html.erb
Form block: app/views/devise/shared/_form_block.html.erb
Login content: app/views/devise/sessions/new.html.erb
Signup content: app/views/devise/registrations/new.html.erb