New Adaptive theme should be default

[pixel]

The theme automatically adjusts to the color scheme and simply gets out of the way. It should be default imo.

[braver]

If it were the default, I would say it shouldn’t use the non-standard title bar on macOS since it disables merging multiple windows. I like how the sidebar and panels match the color scheme though, but those tabs are super handy, especially in full screen, and there is no practical reason to disable them.