On the large font topic: it is Chrome-based browsers specific, they override the font-size in the 'table' element with 'medium' value (I presume it's 16 px), while it should be 10px as specified in html / body styles. You have to explicitly add "font-size: 10px" to #portal-body (table) element to fix this bug.
told ya, the table layout for positioning is bad 
On the login function not working: it have to be a cookies/session problem. I presume, but I'm not sure, that web server was offline for some time, so old user cookies became obsolete and new ones cannot be set (because the old ones are still there). I logged in through an anonymous (private) window and it worked all right; then I removed all of the cookie data for ceonss.net domain, and it worked from a normal window too, including the "Return to previous page" button.
Still, having these server-side problems sucks. Maybe the server itself can be fine-tuned or maybe you should change your hosting company?
Sincerely yours,
100 years ago there was no such thing as a "computer".
