Yeah, for me being a noob it was hard to learn as I didn't know what and where to start. Not much material, at least not in my native language and suitable for a kid. So I learned by brute-force. I applied each and every auto-complete CSS-statement and looked what it did. I didn't know or think of there actually being a reference somewhere online. But testing them, I found the "cool" ones (especially border style, applied it to everything!) and could use them.