Sidebar and inset panel
A workspace sidebar on the window colour with search, quick create and an account menu, and every page in one rounded panel beside it.
App shells
Icon rail sidebar
The same shell with the sidebar folded into an icon rail that explains itself with tooltips and morphs back to full width.
Settings mode
The sidebar switches to a settings rail with a way back to the app, beside a settings page of rows that save as you change them.