# Animation Vocabulary

Turn a vague description of a motion or effect into the precise term, so the user knows what to ask for.

## Quick Start

The user describes an effect loosely. You return the matching term(s) in this format:

```
**Stagger** — Animate several items one after another with a small delay between each, creating a cascade.
```

If several terms could fit, list the best match first, then 1–2 alternates with a one-line note on how they differ.

## Instructions

1. **Read for intent, not keywords.** Users describe what they *see* or *feel* ("springy", "slides off", "draws itself in"), not the technical name. Map the sensation to the glossary below.
2. **Quote the glossary verbatim.** Its descriptions are authoritative — use them as-is, don't paraphrase.
3. **Disambiguate close terms.** When two compete (*Clip-path* vs *Mask*, *Pop in* vs *Bounce*, *Shared element transition* vs *Layout animation*), contrast them so the user can pick.
4. **When nothing matches exactly,** name the closest term and say plainly it's an approximation, or describe the effect in the glossary's vocabulary (e.g. "that's a *stagger* of *scale-in* entrances").
5. **Stay within this glossary.** If a term genuinely isn't here, say so rather than inventing one — though you may explain the concept using these words.
6. **Keep it tight.** A naming question wants a name, not an essay. Lead with the term; expand only if asked.

## Examples

**Example 1 — feel-based**
User: "What's it called when a popover seems to grow out of the button you clicked instead of from its middle?"
Output:
```
**Origin-aware animation** — An element animates out of its trigger, like a popover growing from the button that opened it instead of from its own center which is the default in CSS.
```

**Example 2 — disambiguation**
User: "The thing where one image turns into another image."
Output:
```
**Morph** — One shape smoothly turns into another shape, e.g. Dynamic Island.

Close alternates:
- **Crossfade** — if they simply fade over each other in the same spot.
- **Shared element transition** — if an element travels and transforms from one position into another.
```

**Example 3 — physics feel**
User: "That iOS scroll where it resists and snaps back when you pull too far."
Output:
```
**Rubber-banding** — Resistance and snap-back when you drag past a boundary (the iOS overscroll feel).
```

## Glossary

_A curated snapshot mirroring the project's `/vocabulary` page; keep the two in sync when either changes._

### Entrances & Exits — how elements appear and disappear
- **Fade in / Fade out** — Element appears or disappears by changing opacity.
- **Slide in** — Element enters by sliding in from off-screen (left, right, top, or bottom).
- **Scale in** — Element grows from smaller to full size as it appears, often paired with a fade.
- **Pop in** — Element appears with a slight overshoot, like it bounces into place.
- **Reveal** — Content is uncovered gradually, often by animating a clip-path or mask.
- **Enter / Exit** — The animation an element plays when it's added to or removed from the screen.

### Sequencing & Timing — coordinating multiple elements or moments
- **Keyframes** — Defined points in an animation (0%, 50%, 100%) that the browser fills the gaps between.
- **Interpolation / Tween** — Generating all the in-between frames between a start and end value, so motion is continuous.
- **Stagger** — Animate several items one after another with a small delay between each, creating a cascade.
- **Orchestration** — Deliberately timing multiple animations so they feel like one coordinated motion.
- **Delay** — Time before an animation starts.
- **Duration** — How long an animation takes.
- **Fill mode** — Whether an element keeps its first or last frame's styles before the animation starts or after it ends (e.g. forwards).
- **Stepped animation** — An animation that is divided into discrete steps, like a countdown timer.

### Movement & Transforms — changing an element's position, size, or angle
- **Translate** — Move an element along the X or Y axis.
- **Scale** — Make an element bigger or smaller.
- **Rotate** — Spin an element around a point.
- **Skew** — Slant an element along the X or Y axis, shearing it out of its rectangular shape.
- **3D tilt / Flip** — Rotate in 3D space (rotateX / rotateY) to add depth.
- **Perspective** — How strong the 3D effect looks — a lower value exaggerates depth, like the viewer is closer.
- **Transform origin** — The anchor point a scale or rotation grows or spins from.
- **Origin-aware animation** — An element animates out of its trigger, like a popover growing from the button that opened it instead of from its own center which is the default in CSS.

### Transitions Between States — connecting one state, view, or element to another
- **Crossfade** — One element fades out as another fades in, in the same spot.
- **Continuity transition** — A change that keeps the user oriented by visually connecting before and a

…