How do I move a window so that its title bar is above the visible screen area?

Solution 1:

Enter Full Screen does exactly that. Click the green button located in the top left of most windows or type the keyboard shortcut ⌘ Cmd + CTRL + F You will notice the title bar moves right out of the viewport.

But this can still produce a scrolling window if there is too much content.

Suggestion:

1. Drag the window down to the bottom of the screen.
2. Grab the edge of the window to stretch it taller until you reach the top of the screen.
3. Press Cmd + Shift + 4 then press spacebar once. Click whichever window you would like to capture. Before clicking a window you will notice hovering over a window will highlight it in blue and the mouse will change to a camera.

Unfortunately, you cannot repeat 1 and 2 if the window still contains too much content. This is because on the second attempt to move the stretched window down the window is automatically reformed to fit the screen.