That when we're developing, you edit a sass file, and when you request the CSS file it compiles the SASS to CSS before serving the file. It has been a little while since I set it all up but I think for the SASS example I've made a gist[1] showing the settings you need to make it work. If I recall correctly the key bit is using the .scss as the source file. Then, in production make sure to set `PIPELINE = True` to stop compiling per request.

[1]: https://gist.github.com/Bockit/5408958