Arabic fonts are not supported by defalut you need an api for that so this is what i did to change to arabic font:

1. add this line to the head :
Code:
Only registered members can view the code.
or you can choose other fonts from here : https://fonts.google.com/?subset=arabic

2. go to style.css change font family in the body to

example :

Code:
Only registered members can view the code.
3. try on different browsers to see results