I'm using Google Docs, and I put some text in a header, and it is showing up very close to the top of the page. I want to position the text so that is vertically centered between the top of the page and the bottom of the top margin. For example, if the page has a top margin of 1", I want the text to show up around 0.5" from the very top of the page. This is similar to what Pages on OS X does by default. How can I do this?