CSStyle incompatible with Sass 3.4.22

It seems to have a problem in your library with my current version of Sass

``07 May 12:51:08 - error: Compiling of app/stylesheets/main.sass failed. DEPRECATION WARNING on line 50 of /Users/Loschcode/Google Drive/projects/panda-lo/website/app_front/node_modules/csstyle/csstyle.scss: #{} interpolation near operators will be simplified
in a future version of Sass. To preserve the current behavior, use quotes:

unquote("#{&}")```

Start with csstyle.scss around line 50 and reproduce the compilation of app/stylesheets/main.sass using Sass 3.4.22. Inspect the reported interpolation warning and determine the compatible change; done means the stylesheet compiles without this deprecation warning.

Written by the indexing model from the issue text.