On a standard Macbook - a 1280 x 800 screen resolution - web designers only have access to a minuscule 560px - a full 240 pixels are taken by the default sized dock, the top bar, the default Firefox browser buttons, etc. So - part of this is Firefox’s fault, but the dock - by default - is just gigantic.
Eh. I’m just annoyed that I don’t get to have a full 30% of the window. :wasted: