This is probably not directly a J! problem so if you vote for closing, I'll remove the question.
Joomla 3.3.6 Offline page – there is a login form displayed, but it is not editable, although its HTML looks fine. Even cursor remains in arrow shape over input boxes, it is not changed into
I. Nothing can be typed into text boxes and blue button doesn't respond. I thought it is a browser issue but I can see the same in multiple browsers.