A few points...
- The first line of defense with EVERY computer when it does something unexpected or different is to shut it down and reboot. About 90% of the time this will fix whatever was the problem.
- In this case, since it is related to a web site, the next action to take is to clear the cache and cookies in your web browser, then open the page again.
- There is no "CSS error" in play here. If you are seeing a different font on the "SEARCH" working, it is a browser issue. Here's what the top bar looks like on my machine in Firefox, Safari, and Internet Exploder: