Snoopy: I second that... maybe using a color for the text background, to make sure the foreground contrasts with the background.

Also, is there any chance the "pairs" of the squares we can move to be highlighted as well? It makes it hard to try and find a number between almost 100 others when they're spread out randomly... I remember someone suggesting it using javascript when you over each of the possibilities... butI think it would be fine if the possible pairs were just statically highlighted using plain old HTML... at least they'd be easier to find.