Foldable devices create new user interaction patterns that traditional responsive design alone cannot fully address.
The Device Posture API provides a standard way to model a device's state as either 'continuous' for flat screens or 'folded' for bent screens.
Detect a device's fold state using the `navigator.devicePosture.type` property in JavaScript or the `device-posture` media query in CSS.
The Viewport Segments API complements the Device Posture API by providing CSS properties to query the dimensions of logical screen segments.
Web standards evolve through stages like Working Draft and Candidate Recommendation, with community review at each step.
New web APIs undergo rigorous review to minimize privacy risks like fingerprinting while maximizing accessibility opportunities.
A practical demonstration shows how a web app's UI adapts to a device folding, with the API available in Samsung Internet and behind a flag in Chrome.
Developers can influence the future of the web platform by filing GitHub issues or joining W3C community and working groups.
Questions on testing without a physical device, future support for multi-fold devices, and how fold breakpoints are determined are addressed.
Jobs that call for the skills explored in this talk.