No matter how big font I set for titlebar, the height of the titlebar is not changed at all. I don't see any editbox where I could enter the desired height of titlebar.
So far, I only found workaround, that you should edit window's button (close, maximize, and so on) from current theme. However this is tiresome, because if you decide, that the new height is not OK, and it should be 1 px bigger, you have to rescale the buttons (whole set) again.
I am looking for something theme independent, and straightforward.