Use Scss it is worth it!
There is a Scss folder here You can watch main scss file which will import all necessary scss partials, also Foundation scss files.
In ABC you are able to run only one-word command to achieve Sass compiling and watching for changes. And you don't need to do any additional work.
We have used Grunt task and Node based Sass compilation. To use it just go to ABC theme folder and run
(sudo) npm install then run
grunt. From now on, all your changes in the .scss files will be compiled into .css files. You can check how it looks like here: https://github.com/juliancwirko/abc/blob/master/Gruntfile.js
As you can see there is Sass config section. You can set up the output style of your final .css file, sourcemaps for Sass and of course file names with paths.
For more information check out grunt-sass task: https://github.com/sindresorhus/grunt-sass and read more about working with ABC theme here: http://julian.io/ghost-theming-with-zurb-foundation-and-scss/