From what all was discussed yesterday I think this looks good. One other scenario idk if we want to also try fixing, is if the __header-content container only has the keyboard shortcuts container, the keyboard shortcuts get moved to the left similar to the lanuage tab was doing.

Screenshot and DOM of the "With shortcut menu and main header content" example:

vs removing the controls and header-main containers:

Note this isn't anything to block this PR from merging.

The changes look good to me and no other issues in a spot check. FWIW, longer term I'd advocate to put a header of some sort on the second and third examples since they are demonstrating height adjustments but they look different because they don't have the header.