Ztx14 Motion Cursor Follow

---
name: ztx14-motion-cursor-follow
description: Apply a focused implementation and verification workflow for custom cursor following in Isometric, React, responsive motion, or interactive UI work.
---

# Custom Cursor Following

## Activation
Use this skill when the task includes **custom cursor following**, a related review, a bug report, or a regression test. Load the Isometric master skill first for site-specific installation and source conventions, then only other specialists that are directly relevant.

## Scope and implementation contract
Implement a nonessential cursor follower that never obscures targets, steals input, or replaces the native cursor by default.

Use Pointer Events when appropriate, derive coordinates from current element bounds, coalesce high-frequency input, and keep animation ownership separate from semantic component state. Support pointercancel, focus, touch, and reduced motion; do not make essential meaning mouse-only.

## Execution sequence
1. **Inspect evidence.** Identify the real component, event/state path, installed source, app conventions, and available test commands. Record uncertain assumptions instead of silently filling gaps.
2. **Define the behavior.** Write down the expected initial, active, interrupted, cancelled, and resting states for this specific task. Name the property or state owner before editing.
3. **Implement narrowly.** Apply the smallest safe change that achieves the focus above. Reuse local utilities, tokens, and existing engine behavior before adding a dependency. Preserve unrelated files and styles.
4. **Cover input variants.** Exercise pointer/mouse where applicable, touch or coarse pointer, keyboard/focus, and an equivalent non-hover path. Check reduced-motion behavior and both light/dark themes when relevant.
5. **Measure and verify.** Run the applicable test, type check, and production build. Capture a deterministic screenshot or repeatable interaction trace for visible behavior. If a browser/device is unavailable, mark that check `NOT_TESTED`.

## Acceptance gates
- The behavior is implemented in real source code, not merely described in prose.
- Target selection and visible state match after repeated, rapid, interrupted, and cancelled interactions.
- The responsive layout remains usable at 320, 390, 768, and 1280 CSS px or the project’s actual breakpoints.
- Reduced motion keeps the same information and task outcome without unnecessary continuous movement.
- No new console error, hydration mismatch, stale event listener, idle animation loop, or accidental layout shift is introduced.
- The report names changed files, commands actually run, evidence captured, unresolved issues, and any limitation.

## Failure patterns to avoid
Do not run layout reads per frame, attach competing per-object loops, or let hover be the only way to access information.
- Avoid changing an unrelated theme, route, dependency, or interaction simply to make the local example easier.
- Do not claim success based solely on a source edit; distinguish code inspection, automated tests, and real-browser validation.

## References
- https://developer.mozilla.org/en-US/docs/Web/API/Pointer_events
- https://developer.mozilla.org/en-US/docs/Web/API/Element/pointermove_event
- https://developer.mozilla.org/en-US/docs/Web/API/PointerEvent/getCoalescedEvents
- https://motion.dev/docs/react-use-spring