Button in Masthead changes position on different pages

Hello
I have placed a button in the masthead which works fine on the home page of my site. However, on other pages it is in a different position and covers the logo image.
It seems this occurs because some of the pages are default width and others are full width stretched. Please is there a way to make sure the button stays on the right hand side on all pages?

It would also be great if I could adjust the height of the button.

Thank you.

The page I need help with: [log in to see the link]