Define our own CSS coding styles

The page http://docs.moodle.org/dev/CSS_coding_style defines some of our Coding Style for CSS, but it should contain more details.

The following links seem to be a good source of information:

• https://github.com/csswizardry/CSS-Guidelines
• http://docs.moodle.org/dev/Standardize_classnames_and_layout_to_facilitate_theming
• http://docs.moodle.org/dev/Perth_Hackfest_October_2012/Responsive_design_and_Theming