Marcelo Brongo on "[Plugin: Contact Form 7] How can I change the position of my "submit" buttom in my "contact form 7"?"

I have tried several changes but nothing works. I have tried to change into CSS STYLE margin px, eliminate margin line, put a new line in the bottom of CSS, change class button,.....nothing have worked!!! :-(
I also made severals searchs in google and visualize lots of youtube tutorial but without success!
http://www.corax.cat/contactar-2?lang=en