The BBC Global Experience Language (GEL) Technical Guides are a series of framework-agnostic, code-centric recommendations and examples for building GEL design patterns in websites. They illustrate how to create websites that comply with all BBC guidelines and industry best practice, giving special emphasis to accessibility.
Heydon Pickering (author of Inclusive Components and co-creator of Every Layout) has implemented and documented over 25 of the BBC's design patterns. These are sure to be loaded with best practices and clever tricks for making resilient, accessible modern UI components. (via @heydonworks)