Firefox Compatibility Issues?

I am currently using Safari to write this question.

Firefox, other than the fact that it doesn't support full screen, seems to have some compatibility issues I cannot seem to troubleshoot. Alignment of websites is off. On Facebook, it seems to load up in pure HTML form (no pictures...all the text is on the left). Also, the Google home can't even load up the logo.

Does anyone know how I can fix this? Thanks!