1.) this is Better Battlelog, not Battlelog. We can't fix this issue.
2.) check your LOCAL Browser settings, i think you have disabled CSS in your browser settings AND/OR you have changed the setting to only show HTML code, no CSS and no JS.
3.) if 2. doesn't help, pls try it in the official Battlelog Forum on
http://battlelog.battlefield.com/forum
:-)
GreatApo
Open battlelog with on other browser. If the css runs there, then your browser settings have disabled the css OR you have install an addon that does so.