Preview and layout of UI elements

Hi, everybody, I have 2 questions.

  1. Is it possible to make a full screen in the viewing mode? I want to understand whether the user interface elements are located correctly.
  2. The second question follows from the first. When I use a built-in UI element, such as a health bar,and change the size of the window wider / narrower, the health bar also changes its location on the screen. And when I take the usual progress bar, or any other UI element when changing the size of the window, it remains in place. I have tried all possible settings, but the problem has not been solved. I will be very grateful for any advice or a link to solve this problem.

F11 for full-screen.

With UI elements, make note of where each element, as well as any container object it might be placed in, as to where it's docked and aligned, and then tweak the numbers from there.

Great, thank you very much, I finally figured it out.