Very good "Your browser is not compliant page." The Opera browser is CSS3, 3D Transform, Node.js capable. If you are doing certification using a browser check, do the following: Tell the user their website is not optimized for their browser, suggest the browsers as you have it on your site, then provide the user with the option to continue ahead with their current browser.
In the future, could you just put a small warning, instead of blocking page completely?
I don't mind if I get page without some 3D transition, but a complete block gives an "F*U" impression, even if you are just working on making it perfect.
Here is a link to the logo so you can add it: (http://media.opera.com/media/images/icon/Opera_512x512.png)
Edited to be more constructive and helpful in addressing the issue.