@christianv I tried renaming calcentral.scss to ...erb.scss and wrapping these, but Rails crashes. It looks like you can use it for some variable interpolations, but not for conditional blocks like this, which is annoying. This guy has a solution, but it requires another script:

http://www.krautcomputing.com/blog/2012/03/27/how-to-compile-custom-sass-stylesheets-dynamically-during-runtime/