A smart slugification utility that handles both Latin and non-Latin characters appropriately. For Latin strings it uses slugify() (e.g., 'E2E Testing' → 'e2e-testing'), while preserving non-Latin characters using lodash.kebabcase. This solves a common problem in web applications where proper Unicode handling in URLs/slugs is often overlooked. The function is self-contained, has zero dependencies beyond lodash.kebabcase and slugify, and could be extracted to any project with minimal modification.

Creates valid CSS identifiers for Astro's View Transitions API by properly encoding non-ASCII characters (as Unicode hex sequences) and replacing invalid ASCII special characters with hyphens. It ensures the resulting string is a valid CSS <custom-ident> by handling edge cases like leading digits and empty strings. This demonstrates non-obvious skill in navigating CSS identifier specifications and provides a reusable solution for any project using view transitions that needs to generate safe identifiers from arbitrary strings.

A comprehensive theme management system that handles theme persistence (localStorage), OS preference synchronization, accessibility updates (aria-label), Android browser chrome synchronization via theme-color meta tag, and View Transition compatibility to prevent flashes during navigation. It encapsulates all the complex logic needed for a robust dark/light mode implementation in a single, self-contained module that could be dropped into any web application with minimal adaptation (mainly adjusting the theme selector and storage key).