Show HN: I decided to document and share my high-level CSS best practices 14 years ago
> When building components try and keep a DRY, OO frame of mind.
Two different things here. OO can mean having excessive numbers of things (files, objects) to do something that can be done more clearly and consisely without them, and it could be argued that having additional files is less DRY if you don't need to provide the same amount of code. So it is good to be DRY before OO.