So,
I installed Opera 22.0 today for debugging a website's new CSS without having the ability to access the server. This means I gotta check the CSS file with different browsers by importing it via web development tools. With Firefox this works great, Chrome works too, Opera.. not so much. What I read is that Opera already has an option to add user stylesheets, but when I read the help:
http://help.opera.com/Mac/12.10/en/stylemodes.html

I do not find 'Preferences', there are only Settings. I can't find 'Advanced' in settings. When right clicking a page I can't find 'Edit site preferences'.

Am I to take from this that the browser gets updated more frequently than it's docs?