transitions

Builds a complete CSS motion system — duration and easing tokens (fast 120ms micro-feedback, base 200ms, slow 320ms entrances; standard, decelerate and spring curves), enter/exit/emphasis patterns, stagger rules, and prefers-reduced-motion fallbacks — delivered as a copy-paste CSS/JS snippet library. Use when the user says "add animations", "make this feel smooth", "the transitions are janky", or "animate this modal…