I just honestly measured it with a ruler - in Firefox, from 25 centimeters of the height of my screen, more than 5 eat up toolbars, tabs and other bells and whistles on top (6 lines) and below (status bar and Windows taskbar). You can enlarge the screen: View -> Full screen mode (F11), but even then the address bar and tabs on top, the status bar on the bottom will remain visible.
Daniel Glazman and his
FullerScreen extension will
help us . After installation, select the same menu item “View -> Fullscreen Mode” and enjoy the absolutely full screen - nothing but the site being viewed and, for long pages, the scroll bar on the right.
To return from the “most complete” to the standard full-screen mode, simply move the mouse to the edge of the screen from the top or bottom. The address bar, tabs and status bar appear. To return all your favorite panels to the screen - click on the “Restore” button in the upper right corner.
You can go to Tools -> Add-ons, select the FullerScreen settings and adjust it for yourself. For example, you can turn off the ascent of the status bar if you do not want to watch the endless "Waiting for an answer ... Transferring data ... Done ..." when navigating from page to page. Or increase the width of the bar at the top and bottom of the screen, to which you need to reach with a mouse so that the address bar and tabs appear.
By the way, you can open a new site in the same or in a new tab without leaving our “super-full” screen using Ctrl-L. Search - Ctrl-K. Switch between tabs - as usual, Ctrl-1, Ctrl-2 ...