Pretty good so far.
Suggestions (just suggestions): Possibly a randomly loaded image in the background (there is a tutorial on this site for it somewhere).
Also, you have Contact and Klients. You could possibly switch them to Clients and Kontakt (contact in German).
Keep up the good work!
Also, I am moving this to the Site Check forum because that is what that area is meant for… to check sites and give your opinion and suggestions.