Hi, I am trying to get a fixed border across the site, like this example

http://www.sagmeisterwalsh.com/

I found this tutorial

http://css-tricks.com/body-border/

but I cant make it work for the whole site, since I don't know where to drop the HTML part of the code, I have made it worked using the Raw HTML, but then Is very unstable and would need to apply on each page. 

Wondering if there is a way to drop this on index so it would work across any page.

thanks

Lucas