Please, revert the changes that added a external border to the opera windows.
It was working properly on previous opera versions.
Why?
Its is a well know feature in any windows application that you can just move your cursor to the top right corner and click, to close a window, since windows 95 or early. Without having to AIM on the close button, same for restore and minimize, since you were able to move upwards while moving left or right, because there was no border between the window button and the end of the screen. Now you simple cant do it, as the top right corner is just a border, that affect the entire top screen position, as you can't click on anything on the absolute top position, which just make the usability worse for absolutely no gain what so ever.
And all windows framework, libraries made to build windows app and such, have this built in feature, as opera had it before.
Chrome have this working properly, notepad, steam, word, even java applications like minecraft and you name any other app.
The only way to not have it is to manually make it not work properly. I really don't see why would any one go out of the way to make user experience worse just by adding an external border to the opera windows frame.