Strengthen interfaces against edge cases, errors, internationalization issues, and real-world usage scenarios that break idealized designs. Treat edge cases as design input, not as cleanup after the happy path already shipped. Consult the semantic color reference when designing error, warning, success, and info states so semantic color stays clear and not purely decorative. Consult the status communication reference when hardening notification flows, activity feeds, summaries, or alert settings against fatigue and interruption overload. Consult the image treatment when hardening user-uploaded…