I've re-tested this guide and couldn't replicate your issue.
You can resolve your issue by replacing all of the code in your Child Theme style.css file the code from this PasteBin page: http://pastebin.com/s02E0LZ9
This Diffchecker page shows what I changed: http://www.diffchecker.com/4azwj4nq - Your original stylesheet is on the left and the PasteBin one on the right. The red shows what I removed & green what I added.