Comparing multiple elements at the same time (Pinning)
To compare multiple elements at the same time, you can pin the CSS windows by pressing the "space bar" key. It's useful to check for differences and to edit the CSS.
It makes your compliance work easier. Pinned windows are movable all over the screen and easy to use.
PS: For shortcuts to work - such as the space bar key to pin, the page needs to be focused. If the page is not focused, you'll have to click somewhere first. Or always open the extension via the shortcut, that way the page starts focused.