Shells
The page frame itself. rastrillo new writes one of these as templates/layout.html; a page fills its content hole and overrides whichever chrome blocks it needs. Each demo below is a whole page at its own URL: open one to see it at full width, where the sidebar's rail and the topbar's footer actually have room.
column
The plain centred page every scaffolded app starts on: a skip link, a title, and the content column.
topbar
Brand, navigation and an account menu across the top, with a footer under the page.
sidebar
A navigation rail beside the page. On a phone, the rail is an index page and every other page has a back control. No JavaScript needed.
console
A bar across the top and a navigation rail down the side at once, the shape most admin consoles are. On a phone, the bar's menu opens as a card and the rail is an index page. No JavaScript needed.
stage
One card in the middle of a full-page backdrop, for a screen that stands alone. The sign-in screen is what it is for.