Ah, yes, the Linux (Cinnamon, GNOME) taskbar--never dawned on me. I have two huge monitors so this is about as far away from the open Opera window as you can get. And I usually use the open-window title bar for this. Thank you very much for two workable solutions!
I almost forgot to mention that this feature in Cinnamon at least is called "the panel" rather than "the taskbar" which is a term probably of Windows origin as well as being more descriptive.