Custom PDF Export issue with top-right and margin-right

I’ve tried to minimize the top-right section in the header of the title page with „margin-right: 0cm;” and „margin-right: -2cm;” in @top-right but it didn’t work.
My question to you is: Is it even possible to minimize the top-right section to zero and how?
I’ve tried this in the Global PDF-Layout and the Global PDF Format Template.

background-image: url('http://myimage.png');
background-repeat: no-repeat;
background-position: 100% 60%;
margin-right: 0cm;

Thank You