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A window has many trimmings: title, menu, toolbar, search bar, status bar, scroll bars. At top, right, bottom, left.
They consume too much space (in my opinion). (e.g. 5-6 lines at top..)
Worse, the space (consumed by them) is empty (waste) to a great extent.
They could be glued together a bit. Auto-aligning. Into "one frame".
So my idea is a "one-line thick frame around the window enterieur".

Menu: menu is a tree, and in my opinion there is no absolute need to show 8-10 childs of the root, 2-3 would suffice (slight realign of the tree).
Search bar: (for example which is temporarily shown at bottom, taking up a whole line) could take space from the status bar (or from the menu bar, if there is no urlbar or some other "main textbox" at top).
Scroll bars: they do not need the whole line (side), 1/3 length enough.
Progress bars: the top border can be reused too (the space of the main searc bar, for example).

So let's them integrate, and when the top, right and bottom space is full (for example, in case of a small window), then start using the left border (for example for toolbar).