In immersion, when clicking on a sentence to translate or revise, longer sentences cause the pop-up to appear at the side, and stretch the browser window.
This means, in order to see the pop-up window, it is necessary to scroll the screen to the side.
I suggest, that it would be better for window to pop-up above/below the sentence, at least with longer sentences-- as this would be far more comfortable on smaller laptop screens.
Needing to scroll up or down, on a webpage, is something we are all used to doing all the time, but scrolling left or right, is not, and is thus a bit uncomfortable, decreasing the appeal of immersion.
If it makes any difference, I'm using Windows XP Professional, and the latest version of Firefox.
Oh maybe it's XP, because that OS is soooo old! Also, I would recommend you to try another browser other than Firefox.
Microsoft still supports it; they won't stop supporting it until next year. If you want to talk of an old operating system, talk of the IBM PC DOS. Or MAYBE you could call Windows 98 old...
I saw Windows 8, and it looks too much like something that will try to do everything for me. I don't trust computers enough to give them that much freedom.
You're able to grab the window and move it to the center of the screen. Just click and hold down while you move the mouse, and slide it to the center.
As a side note, Firefox stinks. It works pretty well most of the time, but when it comes to security, not so good. I have seen emails that got hacked by simple web scripts when using Firefox; after that I promptly deleted Firefox from all my computers. I use Google Chrome: chrome.google.com