What problem does it solve? Interfaces built and tested only with perfect data break in production when real users submit 100-character names, emoji, RTL text, trigger API errors, or lose network connectivity. This Skill provides a systematic checklist and code patterns to make UI resilient before release. ## Core Features & Use Cases - Edge-Case Assessment: Systematically test extreme text lengths, emoji/RTL/CJK characters, large datasets, empty states, and concurrent operations. - Hardening Patterns: Apply concrete CSS and JavaScript patterns for text overflow, RTL layout with logical properties, Intl-based date/number formatting, error recovery UI, and reduced-motion support. - Error & Network Resilience: Handle HTTP status codes (400/401/403/404/429/500), offline scenarios, race conditions, and double-submission with retry and rollback strategies. - Use Case: Before shipping a multilingual dashboard, run this Skill to verify German translations don't overflow buttons, Arabic renders right-to-left correctly, and a failed API call shows a retryable error instead of a blank screen. ## Quick Start Use the harden skill to review this interface for edge cases including long text, emoji, RTL languages, network failures, and empty states.
