Make Interfaces Feel Better

Salvaged from a stale community PR and polished up. This gives Claude concrete patterns for UI refinement: concentric radius math for nested rounded corners, optical centering for asymmetric icons, tabular numerals for counters, text-wrap balance and pretty for short content, transition property scoping instead of transition all, and hit area expansion with pseudo-elements. It outputs before/after tables when reviewing changes. Useful when something feels off but you can't articulate why, or when you're building controls and want to skip the flat prototype look. The checklist format makes it easy to audit existing work without overthinking every detail.