HACKING

Summary
-------

* Do not edit the CSS directly, edit the source SCSS files and process them with SASS (run 
  `./parse-sass.sh` when you have the required software installed, as described below)
* To be able to use the latest/adequate version of sass, install sassc.

  On Ubuntu, this is done with 'sudo apt install sassc'

  On Fedora F20, this is done with 'sudo dnf install sassc'

  from the same directory this HACKING resides in.

How to tweak the theme
----------------------

Adwaita is a complex theme, so to keep it maintainable it's written and processed in SASS. The
generated CSS is then transformed into a gresource file during gtk build and used at runtime in a 
non-legible or editable form.

It is very likely your change will happen in the _common.scss file. That's where all the widget 
selectors are defined. Here's a rundown of the "supporting" stylesheets, that are unlikely to be the 
right place for a drive by stylesheet fix:

_colors.scss        - global color definitions. We keep the number of defined colors to a necessary minimum, 
                      most colors are derived form a handful of basics. It covers both the light variant and
                      the dark variant.

_colors-public.scss - SCSS colors exported through gtk to allow for 3rd party apps color mixing.

_drawing.scss       - drawing helper mixings/functions to allow easier definition of widget drawing under
                      specific context. This is why Adwaita isn't 15000 LOC.

_common.scss        - actual definitions of style for each widget. This is where you are likely to add/remove
                      your changes.
                      
You can read about SASS at http://sass-lang.com/documentation/. Once you make your changes to the
_common.scss file, you can either run the ./parse-sass.sh script or keep SASS watching for changes as you
edit.