I have a wordpress blog " www.freelancing4arab.com", I want to change the theme font, I edit the css but nothing changed, obviously my blog is in Arabic so I want to use a cool arabic font.

So what do you think ? what was the problem? why the changes didn't take place ?

And can I use a special font I mean a font that the user doesn't have on there machine but it's uploaded on my server - I know it's possible but I want to know how - 

This is my website css file : <http://freelancing4arab.com/wp-content/themes/WebColors/style.css>