Refactoring Legacy CSS Without the Tears

Before refactoring an old stylesheet, I want to know which pages it serves. A selector that looks unused in one template may matter somewhere else entirely.

I'd start with a contained component, capture the states it needs to support, and compare them after each change. Remove duplication when it's understood, rather than replacing the whole file on sight. The aim is to make the next edit less risky. A smaller stylesheet is welcome, but it isn't proof that the job is done.