# Expandable Card (Notchset): prompt.md (v1.0.0)

- id: `expandable-card` · version 1.0.0 · component · pro (Pro)
- category: Navigation
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/expandable-card`
- npm dependencies: none
- registry dependencies: utils, https://beautiful-ui.dev/r/notchset-foundation.json
- docs: https://beautiful-ui.dev/components/expandable-card
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

A card whose whole header opens it: a kicker, a title, a progress track of nodes and a count that flips as steps complete, and a chevron key that sinks onto its plate. Inside, checkable steps stagger in; checking one blooms its node and extends the track.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: none beyond React.
- Files: `components/ui/notchset/expandable-card.tsx`; shared code: `lib/beautiful-ui/notchset/instrument.tsx`, `lib/beautiful-ui/notchset/root.ts`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `notchset-foundation`.
- Builds: one set of files for both, but its dependencies come in Base UI and Radix builds. Install the one that matches the project (see Install): a free item's bare URL installs the Base UI build of it and its dependencies.
- Exports to keep: `ExpandableCard`, and every exported type.
- CSS: the install adds the notchset foundation (tokens, keyframes, motion levels) to your global stylesheet once. Nothing to import by hand.
- Re-running `add` (or `--overwrite`) re-applies those rules: put overrides in your own CSS, never in the installed rules.
- Tokens: retheme with the `--notchset-*` custom properties (`--notchset-check`, `--notchset-control-edge`, `--notchset-draw-from`, `--notchset-ease-bloom`, `--notchset-ease-travel`, `--notchset-fade`, `--notchset-focus-color`, `--notchset-focus-inset`, `--notchset-life-from`, `--notchset-life-ms`, `--notchset-node-blink`, `--notchset-node-bloom`, `--notchset-node-delay`, `--notchset-plate-color`, `--notchset-rise-from`, `--notchset-rule`, `--notchset-scroll`, `--notchset-signal`, `--notchset-sweep-to`). Never add Tailwind colour classes inside the component.

```tsx
import { ExpandableCard, type ExpandableStep } from "@/components/ui/notchset/expandable-card";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `ExpandableCard` | `expandable-card` | The card. |
| `Trigger` | `expandable-card-trigger` | The header button. |

Style a part with `[data-slot="<slot>"]` selectors or its `className`; keep the attributes when editing.

## Sound
- Keep every `data-slot` and `data-sound` attribute: the sound layer reads them.
- Installing this item adds no audio. Nothing plays until the app mounts `SoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/notchset-sound.json`, import from `@/components/ui/notchset/sound-provider`); `useSound()` gives `muted` and `setMuted` for a mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/notchset/expandable-card.tsx` as the reference implementation before changing or recreating anything, and match it: sizes, colours per theme, motion timings, copy and behaviour.
- If you deviate (a prop you can't honour, a style you changed, a dependency you swapped), say so in your reply, part by part.
- Keep the accessibility contract, the keyboard map and the motion levels listed below.

## Use it when
- expandable card, checklist card, rollout steps, progress checklist, collapsible card, Notchset
- A rollout, onboarding or review checklist that people come back to

### Not when
- Plain content that opens: use Accordion

## Mistakes
- Control steps by passing new done values; the card keeps the user's checks otherwise

## Usage

```tsx
"use client";

import * as React from "react";
import { ExpandableCard, type ExpandableStep } from "@/components/ui/notchset/expandable-card";

export function RolloutChecklist() {
  const [steps, setSteps] = React.useState<ExpandableStep[]>([
    { label: "Run planner-core evals", meta: "88.9%", done: true },
    { label: "Canary at 5%", meta: "24H" },
    { label: "Promote to 100%" },
  ]);
  return (
    <ExpandableCard
      kicker="Migration · Aug 14"
      title="Atlas 3 Flash rollout"
      steps={steps}
      onStepChange={(i, done) => setSteps((s) => s.map((step, k) => (k === i ? { ...step, done } : step)))}
    />
  );
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `title / kicker` | `ReactNode` |  | The header. |
| `steps` | `{ label, meta?, done? }[]` |  | The checklist. |
| `open / defaultOpen / onOpenChange` | `boolean / (open) => void` |  | The open state. |
| `onStepChange` | `(index, done) => void` |  | A step was checked or unchecked. |
| `labels` | `{ progress, complete, justNow }` |  | The words; {done} and {n} are filled in. |

Full docs: https://beautiful-ui.dev/components/expandable-card

## Customising
- Colours: the component reads your shadcn tokens (`--background`, `--foreground`, `--border` …), refined by the `--notchset-*` tokens. The signal colour is `--notchset-signal` (it falls back to `--destructive`). Set tokens on `:root`, or on any container to retheme one area.
- Dark mode follows the `.dark` class on an ancestor (the shadcn and next-themes convention).
- Update later by re-running the install with `--overwrite` (review the diff if you edited it). Changelog: https://beautiful-ui.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| Enter / Space (header) | Open or close |
| Tab | Through the steps |
| Space (step) | Check or uncheck |

## Performance

- Checking a step is local state and one CSS transition; the count flips only when it changes.

## Responsive

- Fills its container; step labels truncate in their row.
- Rows grow to 44px on touch screens.

## Motion inventory

| Interaction | What moves |
|---|---|
| Open | The body unfolds over 460ms; steps stagger in 40ms apart; the key sinks 2px and the chevron turns 180° |
| Check | The node blooms to r 2.4 over 360ms and the track extends over 420ms; the count flips |

## Accessibility contract (preserve when editing)
- The header is one button with aria-expanded and aria-controls
- Steps are checkboxes (role=checkbox, Space toggles)
- The count is a polite live region

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/expandable-card
```

Pro item: needs the `@beautiful-ui-pro` registry in `components.json` and `BEAUTIFUL_UI_TOKEN` in `.env.local` (https://beautiful-ui.dev/account). Setup: https://beautiful-ui.dev/docs/pro. Your components.json `style` picks the build: radix-*, new-york and default get Radix, base-* gets Base UI.

## Credits
- Built on shadcn/ui (https://ui.shadcn.com)

The notchset foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://beautiful-ui.dev/r/notchset-foundation.json.