What problem does it solve? Building software that works across languages, regions, and writing systems requires solving language detection, translation fallback, pluralization, RTL layout, font coverage, and translation quality assurance — this Skill provides the architecture and code patterns for all of them. ## Core Features & Use Cases - Language Detection & Fallback: Implements a detection cascade (user preference, identity provider, Accept-Language header) with CLDR-style fallback chains and BCP 47 locale matching. - Translation & Formatting Patterns: Provides ICU MessageFormat pluralization, locale-aware date/number/currency formatting, and dialect inheritance trees for regional variants like Manezinho Portuguese. - RTL, Fonts & LQA: Covers CSS logical properties for right-to-left languages, Noto font selection per script, pseudo-localization testing, and severity-tiered localization QA. - Use Case: When adding Spanish and Arabic support to a Next.js app, use this Skill to configure next-intl middleware, set up Accept-Language detection, handle RTL layout with logical CSS properties, and write automated tests verifying translation key coverage. ## Quick Start Use the localization skill to set up next-intl middleware with Accept-Language detection and fallback chains for my Next.js app supporting English, Spanish, and Arabic.
