Great tutorials. I'm 61 years young and I've tried to teach myself to code many times in the past, but the problem is that when you get hung up on something there was no real good way to extricate yourself from the problem. So, I would just give up. Your lessons hopefully will change all that.
That being said, I also had problems with getting my css files to render. I read every post above, and tried the unblocking and refreshing the web page etc. etc., and nothing worked.
But this is how I solved my problem: Somewhere above you posted this link:
By following the directions and "unhiding" the file extensions, I found that my styles.css file was actually named styles.css.css. How this happened I have no idea, but I never would have been able to find it if I hadn't "unhid" the file extension.
I simply removed the last .css so it reads styles.css and everying renders fine.
Hope this helps some people.
(By the way; how do I change my avitar--I couldn't find anything on the page to help)