In the first I would like to thank the developer of Montezuma theme. It is so nice and handy.
But Unfortunately it didn't support right to left languages as my language - Arabic.
I tried to put rtl.css in the main folder of the theme, but it didn't work... I think it's not good idea to edit the orginal css files.. I am looking for a way, where I can add a new rtl.css file to customize my theme look. Any help?