Sass is one kind of CSS Preprocessor, it can make CSS development simple and maintainable. But to show its real power we may need to have Compass.This article is to introduce Compass. Once you learn Compass, your CSS development efficiency will be largely improved.Here we assume you have mastered the major uses of CSS, if you know Sass, then it's better. It's still ok if you don't know Sass.1. What is Compass?In simple, Compass it the toolkit of Sass.Sass itself is only a compiler, Compass encapsulates some templates and modules based on Sass. The relationship between Sass and Compass is simil...