I have old (but wonderful, Apple equipment, Bulldog IP and Firefox and it's happening all over.
I've noticed the same thing. My Scrabble website downsized last week and it's now miniature.
Then the both the BBC and the Hotmail all of a sudden decreed they'd have a new wider screen.
I've only got a 10-year old purple iMac and the new sizing doesn't fit.
More scrolling... You can try the Text upsize option in your View menu, but that just means you have to scroll horizontally even more.
There is a little magnify thing you can download, but it takes for ever and doesn't work on MacOX10. Google magnifier.
I'm sure it'll all work out fine eventually. I reckon they're trying to tell us to go out and get a new 'puter.
Blame Bill Gates for stealing Apple's copyrights and making everything far too complicated (and making far too much money for doing so) >>I do!
xL