/animate

name: animate
description: "Motion design pass — adds purposeful animations or removes excessive ones, respecting MOTION_INTENSITY and the project's animation stack. Use when the user asks to add animation, \"make it feel smoother\", fix janky transitions, or trim motion that's distracting. Invoke when the user asks for animate on their UI, or mentions 'animate' alongside design / UI / frontend work."

<!-- HARNESS MIRROR — do not edit here. Canonical source: skills/ or commands/. After editing source, copy into cli/assets/<harness>/ and repo-root harness mirrors. -->

**Context:** this sub-skill is one lens of the broader `ui-craft` skill. If the `ui-craft` skill is also installed, read its SKILL.md first for Discovery + Anti-Slop + Craft Test, then apply the specific lens below.

Add or fix animations in `$ARGUMENTS`. Load the `ui-craft` skill.

**Step 1 — Decision Ladder**: run the Decision Ladder from `references/motion.md` first. Anything that fails it gets removed, not improved.

**Step 2 — Pick the library**:

• If user opted into a stack during Discovery → read `references/stack.md`. Use the matching section (Motion, GSAP, or Three.js). Never mix libraries on the same property.
• Otherwise → CSS transitions / `@keyframes` / `animation-timeline: view()` only.

**Step 3 — Apply motion budget**:

| Element | Budget | |---|---| | Color/opacity | 100-150ms | | Small UI (tooltips, dropdowns) | 150-200ms | | Medium UI (modals, panels) | 200-300ms | | Large UI (page transitions, drawers) | 300-400ms |

Exit ≈ 75% of entrance duration (shorter, same `ease-out` — or a flatter tail like `cubic-bezier(0.4, 0, 1, 1)` for a softer exit). Never `ease-in` on UI (see `references/motion.md`). `cubic-bezier(0.22, 1, 0.36, 1)` is a safe spring-like default.

**Step 4 — Multi-stage sequences** → read `../examples/animation-storyboard.md`. Stagger 30-80ms, not 200ms.

**Step 5 — Respect the knobs**:

• `MOTION_INTENSITY ≤ 3` → hover states only, no entrances, no scroll-triggered.
• `MOTION_INTENSITY 4-7` → standard entrances + hover, one scroll reveal max per section.
• `MOTION_INTENSITY 8+` → scroll-linked, page transitions, magnetic cursor OK (still honor reduced-motion).

**Output**: edit code directly. After each file, print the Review Format table. Flag any animation you removed and why.

**Next step:** `/polish` — the compound details around the motion you just added (rung 1).