# Resizable (Lumen Halo): prompt.md (v1.0.0)

- id: `lumen-resizable` · version 1.0.0 · component · pro (All-Access)
- category: Layout
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/lumen-resizable`
- npm dependencies: react-resizable-panels@^4
- registry dependencies: utils, https://beautiful-ui.dev/r/lumen-foundation.json
- docs: https://beautiful-ui.dev/components/lumen-resizable
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

Panes divided by a hairline that lights into a filament under the pointer and glows in the accent while you drag it; the grip is three small cells, and the arrows move it from the keyboard. shadcn's Resizable, cut from Lumen glass.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: `react-resizable-panels@^4`.
- Files: `components/ui/lumen/resizable.tsx`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `lumen-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: `ResizablePanelGroup`, `ResizablePanel`, `ResizableHandle`, and every exported type.
- CSS: the install merges this item's rules (the registry `css` field) into your global stylesheet, in `@layer components`, and adds the lumen foundation (tokens, keyframes, motion levels) 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 `--lumen-*` custom properties (`--lumen-accent`, `--lumen-accent-text`, `--lumen-bad`, `--lumen-bad-text`, `--lumen-focus`, `--lumen-good`, `--lumen-good-text`, `--lumen-hairline`, `--lumen-ink`, `--lumen-muted-ink`, `--lumen-series-1`, `--lumen-series-2`, `--lumen-series-3`, `--lumen-series-4`, `--lumen-series-5`, `--lumen-series-6`, `--lumen-warn`, `--lumen-warn-text`); this item's CSS also reads `--lumen-radius-k`. Never add Tailwind colour classes inside the component.

```tsx
import { ResizableHandle, ResizablePanel, ResizablePanelGroup } from "@/components/ui/lumen/resizable";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `ResizablePanelGroup` | `resizable-panel-group` | The group. |
| `ResizablePanel` | `resizable-panel` | A pane. |
| `ResizableHandle` | `resizable-handle` | The divider. |

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 `GlassSoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/glass-sound.json`, import from `@/components/beautiful-ui/glass-sound`); `GlassSoundToggle` is its mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/lumen/resizable.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
- resizable panels, split view, split pane, panel group, adjustable layout, sidebar resize, shadcn resizable, Lumen
- A list beside its detail
- An editor with a preview, or a chart above its table

### Not when
- Phones: switch to one pane with a sheet for the detail
- A layout people shouldn't change

## Mistakes
- Set minSize so panes never collapse into unreadable slivers

## Usage

```tsx
import { ResizableHandle, ResizablePanel, ResizablePanelGroup } from "@/components/ui/lumen/resizable";

<ResizablePanelGroup orientation="horizontal">
  <ResizablePanel defaultSize="30%" minSize="20%">Accounts</ResizablePanel>
  <ResizableHandle withHandle />
  <ResizablePanel>Detail</ResizablePanel>
</ResizablePanelGroup>
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `ResizablePanelGroup orientation` | `"horizontal" \| "vertical"` | `"horizontal"` | Side by side, or stacked. |
| `ResizablePanel defaultSize / minSize / maxSize` | `number \| string` |  | Percentages or px (react-resizable-panels 4). |
| `ResizableHandle withHandle` | `boolean` |  | Show the grip. |

Full docs: https://beautiful-ui.dev/components/lumen-resizable

## Customising
- Colours: set the `--lumen-*` tokens on `:root`, or on a container with the `lumen-scope` class to retheme one area. Add the `lumen-inherit` class to follow your shadcn palette instead (`--chart-N`, `--destructive`).
- 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 |
|---|---|
| ← → / ↑ ↓ | Resize |
| Home / End | To the minimum or maximum |

## Motion inventory

| Interaction | What moves |
|---|---|
| Hover | The hairline lights into a filament |
| Drag | It glows in the accent |

## Accessibility contract (preserve when editing)
- Each divider is a separator with its value (react-resizable-panels)
- Keyboard resizing with the arrows, Home and End

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/lumen-resizable
```

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)
- react-resizable-panels (https://github.com/bvaughn/react-resizable-panels)

The lumen 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/lumen-foundation.json.