Formatting has disappeared

I loaded WordPress for a client the end of May 2007, and it was working just fine. (We were using the default theme.) Yesterday, for no apparent reason, all of the formatting disappeared. The hosting company (GoDaddy) can’t seem to find anything wrong, and I’ve re-loaded all of the WordPress files to no avail. I’m stumped and would gratefully welcome and appreciate any advice.

https://www.cohen-center.com