It's very good, especially for a first theme.
The black tab title does not look right to me. How about using a png file and putting an opacity on it so you can slightly see the background through it (like the transparent highlights and popups).
You have a very good eye for design

Note: Be careful putting emails in the theme details. Themes are just archives when you upload them to the internet spam bots will crawl them and put any emails they find in a mail list. I got a lot of spam when i did this. So if you put your email i advise censoring it some how like me [a t] blah dot com.