Video in Header module

Hi,
I want to put a video instead of the form in the Header module (simplicity template).
I have tried tu embed a video with the iframe method but it is impossible to resize the frame or to center. With div tags the responsive mode is no more functioning.

What css could I modify to obtain the desired effect?

Thank you.

Nobody has an idea how to align center an iframe tag in the header section (instead of the form fields - simplicity template)?

I have tried many things but doesn't work!

Thank you for your help.

Georges

Could you please provide me with a URL to your website, either here or via PM (click the “Private Message” text underneath my avatar) so that I may analyze it? It is a lot easier for us to diagnose issues when we have a live site to examine.