I want to control how much top margin of my persona I can see.
I like my persona but I cant see much of it and would like to reduce the browser section from the top so that I can see more of the Persona theme.
Add some Toolbars to see the entire height of the persona image = 3000px by 200px (I don't think the full width of the Persona image can be seen on anything except a wide screen TV display).
Firefox comes with 3 Toolbars, the Menu bar, the Navigation bar, and the Bookmarks toolbar. It may vary depending on your operating system and whether you have Large or Small toolbar icons selected, but on my system I need to have 10 toolbars showing to see the full height of the Persona I have selected. YMMV
View > Toolbars - Customize Then hit the Add New Toolbar button, name that new toolbar (I named them Spacer 1 -7), and then add a single Space to each new Toolbar. Repeat until you have 7 more Toolbars. When you're done - hit the Done button.