Sounds like certain links are being blocked. It might be worth trying to download (browse to) just the CSS of affected pages in case it gives you a useful error message.
I don't know your technical level, so apologies if I'm teaching you to suck eggs
In most web browsers, you can see the source of a page your viewing (the HTML). In Chrome, it's the Spanner icon -> Tools -> View Source.
There should be a piece of code that starts <link near the top that includes a reference to a CSS file such as site.css. This is the link to the CSS file. There will probably be more than one.
Take the link and paste it on the end of the website address. i.e. If your on
www.ea.com and the CSS file in linked as /css/site.css enter :
www.ea.com/css/site.css into your browser and see if you get an error message (404 not found etc).
I've just looked at the EA site and they are using a CDN (content delivery network) to distribute much of the code. These are run by third parties who may be having issues. This is one of the CSS files from the site.
http://cdn.easf.www.easports.com/uk/football/static/css/bundle/easf_en_GB.css
Also, if you've recently upgrade or installed an AntiVirus program, this may be causing issues too.
Hope this helps
Steve