define four essential principles for accessible Bitcoin design: Perceivable: Information and user interface components must be presentable to users in ways they can perceive. (e.g., text alternatives, captions, adaptable formats). Operable: UI components must be operable by all users (e.g., keyboard navigation, seizure-safe designs, clear wayfinding). Understandable: Information and the operation of the user interface must be understandable (e.g readable, predictable, and help users avoid mistakes) - critical in Bitcoin apps. Robust: Content must work reliably with current and future user agents and assistive technologies using clean, standards-compliant code.