Which style element is responsible for positioning?

Hello,

which style element is responsible for the padding from the upper left corner? For example, in help.antville.org, the title graphic ("ANTVILLE HELP" plus lot of dots) is not exactly positioned in the upper left corner of the browser window.

Instead of this:

I would like to have it this way:

Tried to change parameters in the stylesheet, but this did not help.

Thanks!