Need help coding den!

I am greatly out of practice with CSS coding, and keep managing to break my den code just by trying to mess with colors! I think currently it's just a lack of understanding where goes where, and I had it working but trying to fix the issues, I managed to break it again.

Currently I'm really just trying to get it to work again so I can reupload and then get help figuring out where I need to be putting stuff (unless you can guide me just by looking at the code?) 

Please help! I ran it through CSS Lint but it didn't find anything that suggested the code itself is broken so I'm assuming it's just how it's trying to apply to the den? Here's the link.

https://www.dropbox.com/s/9vtwuc7nux18cau/Wolvden.css?dl=0

I probably can’t help but letting you know that it says the file has been deleted when I click on it