Motion Principles Decide how something should move so it feels right — independent of the tool used to build it. This skill answers timing, easing, spacing, weight, and rhythm. It does not pick a tech stack; it produces concrete numbers (durations, cubic-bezier curves, stagger offsets, spring configs) ready to hand to any implementation. When to use - Motion feels stiff, floaty, mechanical, robotic, or cheap and needs diagnosis. - Choosing a clip or transition's duration, easing curve, and stagger offset. - Reviewing whether motion respects physics intuition (weight, follow-through, arcs). -…