Shut the site down in your browser. You're seeing the default for tPF. Every browser has setting for fonts, colors and style. It usually doesn't matter but your browser was changed by something. Your re-installation is a different matter.
I like Verdana for reading and all my browsers show me that. If it gets overridden I see what ever the web master wants. Computers do funny things a lot of the time. No reason for it but I wouldn't want a computer driving my car.
The problem is solved so to hell with it anyway.