From a comment by Monica Cellio amplifying a comment from msh210:
Control (or command) 0 resets to the default, and from there you can use + or - to get to the size you want. I find that this approach can get me past weird states more quickly than trying to figure out what went wrong.
The problem is that the Georgia font, which is used for this site, doesn't have a Hebrew implementation, and therefore the font that is used is the next in line of declaration - Times New Roman - which doesn't look good in Hebrew.
As far as I know, Arial font is the recommendation for Hebrew on the web. While I haven't tried this method, there is a way to ...