Support page text HUGE

Not sure where this should go since the problem shows up in both Safari and Firefox, but I'm getting HUGE text - with lots of white space to the right and left of the text. Here is an example:

How to unlock your iPhone for use with another carrier - Apple Support

When I go to that page in either Safari or Firefox (on both my 2013 iMac and 2008 Macbook), my screen only shows a tiny part of the first letter. It is way over on the lower left. If I made the window a little smaller, I wouldn't see any of the text without scrolling. When I do scroll, only two lines of text show at a time and I have to scroll horizontally to read the whole line.

Strangely, when I tried Chrome, it looked fine.

This affects other support pages too, though I haven't checked more than a few. I reported this originally on the Firefox forums and others had problems too - yet one person did not. No idea what is going on.