website: www.bh-init.com

am trying to change the font size when a user selects arabic languge.
my english font size is perfect but when its switched to arabic the font size is really small, am trying to modify the arabic font size without changing the english font size but i cant seem to get it work.

i know i can change the font sizes using stylesheet but if i do that my english font will also change and the website is going to look ugly in english languge