The shell theme I've personally used for months. It contains only slight variations from horst3180's original Arc shell theme, and so just about all credit goes to him. I made a few variations I think contribute to the consistency and visual appeal, most noticeably the dash, panel and legacy tray. This was made & tested only on GNOME 3.20 on Fedora 24.
Get the original theme here: github.com/horst3180/Arc-theme