The tabs don't hang in the top left corner but there's some space. I don't get this design decision. Also I dislike the hard dark outlines on some icons (e.g. for folders).
Which is configurable.
This adds a macOS-style title bar and flushes the tabs to the left of the window.
Btw: What I mean is the space left from the first tab, not the "drag space" on top.
The drag space should enable/disable both, the space left of the first tab, and above the tabs.