A book and set of layout primitives (Stack, Sidebar, Switcher and more) that adapt to their space without media queries.

A book and website by Heydon Pickering and Andy Bell on building layouts from small, composable primitives that adapt to their content without breakpoints. Layouts covered include Stack, Box, Center, Cluster, Sidebar, Switcher, Cover, Grid, Frame, Reel, Imposter, Icon and Container.
Each layout has an explanation, a code generator and a custom element version. The Stack, Sidebar and Switcher layouts and the introductory rudiments are free to read.
Buying it gets you all site content and generators (available offline), the book as EPUB, the full set of layouts as custom elements and free updates.
gridclamp()