Website layout messed up

Well, we know what the problem is (missing CSS), but don't know why your machine blocks the file. Turn off blocking stuff (firewall, antivirus, adblocker, whatever) one by one with nothing else running and see if you can load the CSS file from my earlier post. As long as you can not load that page you can't view the layout properly.
 
Are you running adblock plus?
 
Try creating a new Firefox profile and see if it works there.
 
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