Shubhie Panicker: CSS module system in Google+
Why modular CSS? In large scale apps managing CSS dependencies is cumbersome. Lack of granular CSS deps leads to pulling in unnecessary CSS on page render causing bloat. When refactoring code, the CSS order can change disfiguring the rendered page. Also, since it’s hard to know which CSS effects which parts of the page, all of the CSS is bundled together and downloaded at initialization, so the initial page load time is slowed down.