Surely anyone will agree that GWT badly requires a better CSS report. While the CSS resources introduced in GWT where a major step forward, CSS3 is here and it would really be great to have Closure Stylesheets working with GWT:
Closure Stylesheets is an extension to CSS that adds variables, functions, conditionals, and mixins to standard CSS. The tool also supports minification, linting, RTL flipping, and CSS class renaming.
GSS is a open source project at Github that brings a lot of CSS magic to GWT. It is planned to merge into GWT 3.0, but you can use it right now.
Unlike stated in the Github page, GSS does not require a trunk version of GWT as soon as you start using GWT 2.6â€¦