# Kbd (Notchset): prompt.md (v1.0.0)

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

shadcn's Kbd and KbdGroup in Notchset: mono key caps with a 1px edge for buttons, menus and hints. Write keys once (mod+k) and they show for the platform (⌘ or Ctrl). Shortcut shows a combo and runs it, pressing its caps in as the keys go down; sequences like G then R wait 1.2s; shortcuts stay inside their scope and never fire while you type.

## 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/kbd.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: `Kbd`, `KbdGroup`, `KbdProvider`, `Shortcut`, `keyLabel`, `useIsMac`, `useShortcut`, 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-glide`, `--notchset-ease-key-down`, `--notchset-ease-key-up`, `--notchset-ease-travel`, `--notchset-fade`, `--notchset-focus-color`, `--notchset-focus-inset`, `--notchset-grow-to`, `--notchset-key-down`, `--notchset-key-up`, `--notchset-life-from`, `--notchset-life-ms`, `--notchset-node-blink`, `--notchset-node-bloom`, `--notchset-node-delay`, `--notchset-plate-color`, `--notchset-rise-from`, `--notchset-rule`, `--notchset-scan-to`, `--notchset-scroll`, `--notchset-sheet-from`, `--notchset-signal`, `--notchset-sweep-to`, `--notchset-travel`). Never add Tailwind colour classes inside the component.

```tsx
import { Kbd, KbdGroup, Shortcut } from "@/components/ui/notchset/kbd";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `Kbd` | `kbd` | One key cap. |
| `KbdGroup` | `kbd-group` | Caps side by side. |
| `Shortcut` | `shortcut` | A combo or sequence that shows and runs. |
| `KbdProvider / useShortcut` | `kbd` | Pin the platform; bind keys without a hint. |

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://notchset.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/kbd.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
- kbd, keyboard shortcut, hotkey, key cap, shortcut hint, command key, Notchset
- Showing the shortcut for an action in a button or menu
- A page with keyboard shortcuts and a ? sheet

### Not when
- Code or commands: use Code Block

## Mistakes
- Scope page shortcuts to their area so they don't fight the browser's
- Show the same shortcut you bind (write it once in keys)

## Usage

```tsx
import { Kbd, KbdGroup, Shortcut } from "@/components/ui/notchset/kbd";

export function SearchHint({ focus }: { focus: () => void }) {
  return (
    <>
      <KbdGroup><Kbd k="mod" /><Kbd k="k" /></KbdGroup>
      <Shortcut keys="mod+k" onTrigger={focus} />
    </>
  );
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `k (Kbd)` | `string` |  | A key name (mod, shift, enter, k) shown for the platform. |
| `keys (Shortcut)` | `string` |  | A combo (mod+k) or a sequence (g r). |
| `onTrigger (Shortcut)` | `() => void` |  | Runs on the keys; without it the shortcut is only a hint. |
| `scope (Shortcut, useShortcut)` | `RefObject<HTMLElement>` |  | Fire only while focus is inside this element. |
| `platform (KbdProvider)` | `'auto' \| 'mac' \| 'windows'` |  | Pin the symbols; auto reads the device. |

Full docs: https://notchset.dev/components/kbd

## 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://notchset.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| Your keys | Run the action; the caps press in |

## Performance

- One keydown listener per Shortcut, removed on unmount.

## Responsive

- Caps don't wrap; hide hints on touch screens if they add nothing.

## Motion inventory

| Interaction | What moves |
|---|---|
| Press | The caps move down 1px and fill (140ms) |

## Accessibility contract (preserve when editing)
- A Shortcut is read as its keys (⌘ + K, G then R)
- Letter shortcuts never fire inside text fields

## Install

Base UI project (a base-* style in components.json):

```bash
npx shadcn@latest add https://notchset.dev/r/kbd.json
```

Radix project (a radix-*, new-york or default style):

```bash
npx shadcn@latest add https://notchset.dev/r/radix-nova/kbd.json
```

Or add the `@notchset` registry to components.json and run `npx shadcn@latest add @notchset/kbd`: the CLI picks the build from your style.

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

## Source (Base UI build)

### components/ui/notchset/kbd.tsx

```tsx
"use client";

/**
 * Kbd (Notchset) v1.0.0 · Notchset
 * Docs: https://notchset.dev/components/kbd
 * MIT licensed: free to use, change and share.
 */

import * as React from "react";
import { cn } from "@/lib/utils";
import { composing, useLatest } from "@/lib/beautiful-ui/notchset/instrument";

/*
 * Notchset Kbd (one build: no primitive). shadcn's Kbd and KbdGroup, in Notchset: key caps in mono 12px
 * with a 1px edge, for buttons, menus and hints. Keys are written once ("mod+k", "shift+enter") and shown
 * for the platform (⌘ or Ctrl, ⌥ or Alt, ↵ or Enter); KbdProvider pins a platform. Shortcut shows a
 * combo and runs it: its caps press in (1px, filled, 140ms) when the keys go down. A sequence ("g r")
 * waits 1.2s for its second key. Shortcuts fire only inside their scope and never while you type.
 */

export type KbdPlatform = "auto" | "mac" | "windows";
const PlatformContext = React.createContext<KbdPlatform>("auto");

function KbdProvider({ platform, children }: { platform: KbdPlatform; children: React.ReactNode }) {
  return <PlatformContext value={platform}>{children}</PlatformContext>;
}

const macQuery = () => /Mac|iPhone|iPad/.test(navigator.platform || navigator.userAgent);
/** True on Apple platforms (server render: false, then corrected on the client). */
function useIsMac(platform: KbdPlatform = "auto") {
  const auto = React.useSyncExternalStore(
    () => () => {},
    macQuery,
    () => false,
  );
  return platform === "auto" ? auto : platform === "mac";
}

const MAC: Record<string, string> = { mod: "⌘", cmd: "⌘", meta: "⌘", ctrl: "⌃", alt: "⌥", option: "⌥", shift: "⇧", enter: "↵", return: "↵", backspace: "⌫", delete: "⌦", escape: "Esc", esc: "Esc", tab: "⇥", up: "↑", down: "↓", left: "←", right: "→", space: "Space" };
const WIN: Record<string, string> = { mod: "Ctrl", cmd: "Ctrl", meta: "Win", ctrl: "Ctrl", alt: "Alt", option: "Alt", shift: "Shift", enter: "Enter", return: "Enter", backspace: "Backspace", delete: "Del", escape: "Esc", esc: "Esc", tab: "Tab", up: "↑", down: "↓", left: "←", right: "→", space: "Space" };

/** One key's label for the platform: "mod" → ⌘ or Ctrl; letters upper-case. */
function keyLabel(key: string, mac: boolean) {
  const k = key.trim().toLowerCase();
  return (mac ? MAC : WIN)[k] ?? (k.length === 1 ? k.toUpperCase() : key);
}

const kbdClass =
  "inline-flex h-5 min-w-5 flex-none items-center justify-center border border-solid border-[var(--notchset-control-edge,var(--input))] bg-background px-1 font-mono text-[12px] leading-none font-medium whitespace-nowrap text-foreground transition-[background-color,color,translate,border-color] duration-[140ms] ease-linear data-[pressed]:translate-y-px data-[pressed]:border-primary data-[pressed]:bg-primary data-[pressed]:text-primary-foreground";

/** A key cap. Give it `k` ("mod", "enter", "k") for the platform's label, or children as written. */
function Kbd({ k, pressed, className, children, ...props }: React.ComponentProps<"kbd"> & { k?: string; pressed?: boolean }) {
  const mac = useIsMac(React.useContext(PlatformContext));
  return (
    <kbd data-slot="kbd" data-pressed={pressed || undefined} className={cn(kbdClass, className)} {...props}>
      {k ? keyLabel(k, mac) : children}
    </kbd>
  );
}

function KbdGroup({ className, ...props }: React.ComponentProps<"span">) {
  return <span data-slot="kbd-group" className={cn("inline-flex items-center gap-1", className)} {...props} />;
}

type Step = { mod: boolean; ctrl: boolean; alt: boolean; shift: boolean; key: string; parts: string[] };
/** "mod+shift+k" → a step; "g r" → two steps. */
function parse(keys: string): Step[] {
  return keys
    .trim()
    .split(/\s+/)
    .map((combo) => {
      const parts = combo.split("+").filter(Boolean);
      const lower = parts.map((p) => p.toLowerCase());
      const key = lower.find((p) => !["mod", "cmd", "meta", "ctrl", "alt", "option", "shift"].includes(p)) ?? "";
      return { mod: lower.some((p) => p === "mod" || p === "cmd" || p === "meta"), ctrl: lower.includes("ctrl"), alt: lower.includes("alt") || lower.includes("option"), shift: lower.includes("shift"), key, parts };
    });
}
const NAMED: Record<string, string> = { enter: "enter", return: "enter", esc: "escape", escape: "escape", space: " ", up: "arrowup", down: "arrowdown", left: "arrowleft", right: "arrowright", backspace: "backspace", delete: "delete", tab: "tab" };
function matches(e: KeyboardEvent, s: Step, mac: boolean) {
  const key = e.key.toLowerCase();
  const want = NAMED[s.key] ?? s.key;
  // "?" arrives with Shift held: a printable symbol matches by itself.
  const symbol = want.length === 1 && !/[a-z0-9]/.test(want);
  if (key !== want) return false;
  const modDown = mac ? e.metaKey : e.ctrlKey;
  if (s.mod !== modDown || s.alt !== e.altKey) return false;
  if (!symbol && s.shift !== e.shiftKey) return false;
  if (s.ctrl && !e.ctrlKey) return false;
  return true;
}

/**
 * Runs `run` on the keys (a combo, or a sequence like "g r" with 1.2s for the second key) while focus is
 * inside `scope` (or anywhere when it is omitted), never while typing unless the combo has a modifier.
 * Returns which step is pressed (for the caps) and whether a sequence is waiting.
 */
function useShortcut(keys: string, run: () => void, { scope, enabled = true }: { scope?: React.RefObject<HTMLElement | null>; enabled?: boolean } = {}) {
  const platform = React.useContext(PlatformContext);
  const mac = useIsMac(platform);
  const latest = useLatest(run);
  const [pressed, setPressed] = React.useState(-1);
  const [waiting, setWaiting] = React.useState(false);
  React.useEffect(() => {
    if (!enabled) return;
    const steps = parse(keys);
    let at = 0;
    let timer: ReturnType<typeof setTimeout> | undefined;
    let release: ReturnType<typeof setTimeout> | undefined;
    const reset = () => {
      at = 0;
      setWaiting(false);
    };
    const onKey = (e: KeyboardEvent) => {
      if (composing(e) || e.repeat) return;
      // Keys sent to the window itself have no element target.
      const target = e.target instanceof Element ? e.target : null;
      if (scope?.current && !(target && scope.current.contains(target))) return;
      const step = steps[at]!;
      const typing = target?.closest("input, textarea, select, [contenteditable=true]");
      if (typing && !step.mod && !step.ctrl && !step.alt) return;
      if (!matches(e, step, mac)) {
        if (at > 0) reset();
        return;
      }
      e.preventDefault();
      clearTimeout(timer);
      clearTimeout(release);
      setPressed(at);
      release = setTimeout(() => setPressed(-1), 140);
      if (at < steps.length - 1) {
        at++;
        setWaiting(true);
        timer = setTimeout(reset, 1200);
        return;
      }
      reset();
      latest.current();
    };
    window.addEventListener("keydown", onKey);
    return () => {
      window.removeEventListener("keydown", onKey);
      clearTimeout(timer);
      clearTimeout(release);
    };
  }, [keys, mac, scope, enabled, latest]);
  return { pressed, waiting };
}

/**
 * A shortcut hint that also runs: the caps for `keys` ("mod+k", "g r"), pressed in while the keys go
 * down. Without onTrigger it is only a hint.
 */
function Shortcut({
  keys,
  onTrigger,
  scope,
  className,
  ...props
}: Omit<React.ComponentProps<"span">, "children"> & { keys: string; onTrigger?: () => void; scope?: React.RefObject<HTMLElement | null> }) {
  const { pressed } = useShortcut(keys, () => onTrigger?.(), { scope, enabled: Boolean(onTrigger) });
  const mac = useIsMac(React.useContext(PlatformContext));
  const steps = parse(keys);
  const label = steps.map((s) => s.parts.map((p) => keyLabel(p, mac)).join(" + ")).join(" then ");
  return (
    <span data-slot="shortcut" role="img" aria-label={label} className={cn("inline-flex items-center gap-1.5", className)} {...props}>
      {steps.map((s, i) => (
        <KbdGroup key={i} aria-hidden>
          {s.parts.map((p) => (
            <Kbd key={p} k={p} pressed={pressed === i} />
          ))}
        </KbdGroup>
      ))}
    </span>
  );
}

export { Kbd, KbdGroup, KbdProvider, Shortcut, keyLabel, useIsMac, useShortcut };
```

### lib/beautiful-ui/notchset/instrument.tsx

```tsx
"use client";

import * as React from "react";
import { createPortal } from "react-dom";
import { cn } from "@/lib/utils";

/*
 * Notchset instrument parts, shared by every member of a pack: the node (a round light that reports
 * state), the legend printed above a control, the plate a key presses onto, the traced check, the
 * five-tick scanner, and the glyph flip that lands a changed label left to right. Nodes and checks
 * are inline SVG (round at every DPR); the CSS lives in the Notchset foundation. Also: the one motion
 * policy (reduced motion or a data-motion="off" ancestor), ref composition, the portal container
 * and the sound attributes every Notchset root carries.
 */

// ---------------------------------------------------------------------------------------------
// Motion, refs, portals, sound
// ---------------------------------------------------------------------------------------------

/**
 * Whether motion is off for an element, kept live: it follows the OS reduced-motion setting and any
 * data-motion attribute change above it, so a preference switched mid-playback stops decoration at once.
 */
export function useMotionOff(ref: React.RefObject<Element | null>) {
  const [off, setOff] = React.useState(false);
  React.useEffect(() => {
    const read = () => setOff(motionOff(ref.current));
    const r = requestAnimationFrame(read);
    const mq = window.matchMedia?.("(prefers-reduced-motion: reduce)");
    mq?.addEventListener?.("change", read);
    const mo = new MutationObserver(read);
    mo.observe(document.documentElement, { attributes: true, attributeFilter: ["data-motion"], subtree: true });
    return () => {
      cancelAnimationFrame(r);
      mq?.removeEventListener?.("change", read);
      mo.disconnect();
    };
  }, [ref]);
  return off;
}

/**
 * The microphone, or a rejection after `timeoutMs` (a prompt left open, a denied permission). A stream
 * that arrives after the timeout is stopped at once, so a late "Allow" never leaves the mic on.
 */
export function requestMic(timeoutMs = 5000): Promise<MediaStream> {
  if (typeof navigator === "undefined" || !navigator.mediaDevices?.getUserMedia) return Promise.reject(new Error("no mic"));
  const ask = navigator.mediaDevices.getUserMedia({ audio: true });
  return new Promise((resolve, reject) => {
    let late = false;
    const t = setTimeout(() => {
      late = true;
      reject(new Error("timeout"));
    }, timeoutMs);
    ask.then(
      (stream) => {
        clearTimeout(t);
        if (late) stream.getTracks().forEach((track) => track.stop());
        else resolve(stream);
      },
      (err) => {
        clearTimeout(t);
        reject(err);
      },
    );
  });
}

/** True under prefers-reduced-motion or inside a data-motion="off" scope. Checked when an effect runs. */
export function motionOff(el: Element | null | undefined) {
  if (typeof window === "undefined") return true;
  if (window.matchMedia?.("(prefers-reduced-motion: reduce)").matches) return true;
  return Boolean(el?.closest('[data-motion="off"]'));
}

function assignRef<T>(ref: React.Ref<T> | undefined, node: T | null): () => void {
  if (typeof ref === "function") {
    const cleanup = ref(node);
    return typeof cleanup === "function" ? cleanup : () => ref(null);
  }
  if (ref) (ref as React.RefObject<T | null>).current = node;
  return () => {
    if (ref) (ref as React.RefObject<T | null>).current = null;
  };
}

/**
 * Puts text on the clipboard. Resolves true once it is there and false when the browser refuses (no
 * permission, an insecure page, no clipboard API), so a "copied" state is only ever shown for a copy.
 */
export async function copyText(text: string): Promise<boolean> {
  try {
    await navigator.clipboard.writeText(text);
    return true;
  } catch {
    return false;
  }
}

/** The glide easing shared by travelling marks (selection blocks, highlights, runs). */
export const GLIDE = "cubic-bezier(.65,0,.35,1)";

/** Base UI's className may be a function of state: merges ours with it in either form. */
export const withClass =
  <S,>(base: string, className: string | ((state: S) => string | undefined) | undefined) =>
  (state: S) =>
    cn(base, typeof className === "function" ? className(state) : className);

/** Composes two refs, keeping React 19 ref cleanups. */
export function useComposedRefs<T>(a: React.Ref<T> | undefined, b: React.Ref<T> | undefined): React.RefCallback<T> {
  return React.useCallback(
    (node: T | null) => {
      const release = [assignRef(a, node), assignRef(b, node)];
      return () => release.forEach((f) => f());
    },
    [a, b],
  );
}

/**
 * Runs each step on its own animation frame, in order (the first on the next frame), and returns one
 * cancel that stops whichever frame is pending. A no-op step just waits a frame: frames(set pre, wait,
 * go) lets the browser paint the start state before the transition begins.
 */
export function frames(...steps: (() => void)[]): () => void {
  let id = 0;
  let i = 0;
  const tick = () => {
    steps[i++]?.();
    if (i < steps.length) id = requestAnimationFrame(tick);
  };
  id = requestAnimationFrame(tick);
  return () => cancelAnimationFrame(id);
}
export const wait = () => {};

let idSeq = 0;
/** A unique id for something the user creates (a milestone, a note): random where the browser can, else a counter. */
export const newId = () => (typeof crypto !== "undefined" && "randomUUID" in crypto ? crypto.randomUUID() : `id-${Date.now()}-${++idSeq}`);

/**
 * True while an input method (Japanese, Chinese, Korean…) is composing: Enter, Tab and delimiters
 * then belong to the composition, not to the component. keyCode 229 covers Safari's late flag.
 */
export function composing(e: React.KeyboardEvent | KeyboardEvent) {
  const native = "nativeEvent" in e ? e.nativeEvent : e;
  return native.isComposing || native.keyCode === 229;
}

const hotkeyOwners = new Map<string, number[]>();
let hotkeySeq = 0;
/**
 * A page-wide shortcut ("/" or "mod+k", mod being ⌘ or Ctrl) with a single owner: when several
 * components claim the same key, only the one mounted last answers, so one press never opens two.
 * A plain key is ignored while typing in a field.
 */
export function useHotkey(combo: string | undefined, run: () => void) {
  const latest = useLatest(run);
  React.useEffect(() => {
    if (!combo) return;
    const me = ++hotkeySeq;
    const stack = hotkeyOwners.get(combo) ?? [];
    stack.push(me);
    hotkeyOwners.set(combo, stack);
    const mod = combo.startsWith("mod+");
    const key = (mod ? combo.slice(4) : combo).toLowerCase();
    const onKey = (e: KeyboardEvent) => {
      if (hotkeyOwners.get(combo)?.at(-1) !== me || e.key.toLowerCase() !== key) return;
      if (mod ? !(e.metaKey || e.ctrlKey) : e.metaKey || e.ctrlKey || e.altKey) return;
      if (!mod && (e.target as HTMLElement | null)?.closest("input, textarea, select, [contenteditable=true]")) return;
      e.preventDefault();
      latest.current();
    };
    window.addEventListener("keydown", onKey);
    return () => {
      window.removeEventListener("keydown", onKey);
      const s = hotkeyOwners.get(combo) ?? [];
      s.splice(s.indexOf(me), 1);
    };
  }, [combo, latest]);
}

/** Keeps the latest value in a ref, for callbacks read inside timers and animation frames. */
export function useLatest<T>(value: T) {
  const ref = React.useRef(value);
  React.useLayoutEffect(() => {
    ref.current = value;
  });
  return ref;
}

/*
 * Where Notchset overlays (menus, popovers, tooltips) portal to. Unset, document.body, as shadcn's
 * do. Provide an element to keep them inside a scoped theme: a preview, a widget, a shadow root.
 */
export const NotchsetPortalContext = React.createContext<HTMLElement | null>(null);
export function useNotchsetPortal(): HTMLElement | undefined {
  return React.useContext(NotchsetPortalContext) ?? undefined;
}

const subscribeNothing = () => () => {};

/**
 * A scope that turns motion or sound off for everything inside it, popups included. A plain
 * data-motion="off" wrapper can't reach a menu that portals to the body; this one also gives its
 * overlays a portal host carrying the same preferences (inside any outer scope's host), so motionOff
 * and the cues see them there too.
 */
export function NotchsetScope({ motion, sound, children, ...props }: React.ComponentProps<"div"> & { motion?: "off"; sound?: "off" }) {
  const outer = React.useContext(NotchsetPortalContext);
  const [host, setHost] = React.useState<HTMLElement | null>(null);
  const client = React.useSyncExternalStore(subscribeNothing, () => true, () => false);
  return (
    <div data-motion={motion} data-sound={sound} {...props}>
      <NotchsetPortalContext value={host ?? outer}>{children}</NotchsetPortalContext>
      {client && createPortal(<div ref={setHost} data-slot="notchset-scope-host" data-motion={motion} data-sound={sound} />, outer ?? document.body)}
    </div>
  );
}

export { NOTCHSET_ROOT, OWN_SOUND } from "@/lib/beautiful-ui/notchset/root";

// ---------------------------------------------------------------------------------------------
// Parts
// ---------------------------------------------------------------------------------------------

export type NodeState = "off" | "on" | "live" | "signal";

/** The node: a 9×9 ring whose dot blooms on (`on`), blinks (`live`) or turns signal. */
function Node({ state = "off", delay, className, style, ...props }: Omit<React.ComponentProps<"svg">, "children"> & { state?: NodeState; delay?: number }) {
  return (
    <svg
      aria-hidden
      data-slot="indicator"
      data-state={state}
      width="9"
      height="9"
      viewBox="0 0 9 9"
      className={cn(`notchset-node`, className)}
      style={delay ? ({ "--notchset-node-delay": `${delay}ms`, ...style } as React.CSSProperties) : style}
      {...props}
    >
      <circle data-slot="indicator-ring" cx="4.5" cy="4.5" r="3.25" fill="none" strokeWidth="1" />
      <circle data-slot="indicator-dot" cx="4.5" cy="4.5" />
    </svg>
  );
}

/** A small solid round mark (the node where a leader meets a popup, a pointer): SVG, round at every DPR. */
function Dot({ size = 7, className, style }: { size?: number; className?: string; style?: React.CSSProperties }) {
  return (
    <svg aria-hidden width={size} height={size} viewBox={`0 0 ${size} ${size}`} className={cn("pointer-events-none absolute overflow-visible", className)} style={style}>
      <circle cx={size / 2} cy={size / 2} r={size / 2} fill="currentColor" />
    </svg>
  );
}

/** The legend: a mono label above a control, with an optional node (or any trailing reading). */
function Legend({ label, node, children, className, ...props }: React.ComponentProps<"div"> & { label?: React.ReactNode; node?: NodeState }) {
  return (
    <div data-slot="legend" className={cn(`notchset-legend`, className)} {...props}>
      <span data-slot="legend-label">{label}</span>
      {(children != null || node) && (
        <span data-slot="legend-reading" className="flex items-center gap-2">
          {children}
          {node && <Node state={node} />}
        </span>
      )}
    </div>
  );
}

/** A key on its plate: the plate is an offset frame behind the child; `--notchset-plate-color` tints it. */
function Plated({ className, children, ...props }: React.ComponentProps<"span">) {
  return (
    <span data-slot="plated" className={cn("relative inline-flex", className)} {...props}>
      <span aria-hidden data-slot="plate" className={`notchset-plate`} />
      {children}
    </span>
  );
}

/**
 * The success check. Mounted, it traces itself in over --notchset-check (instant under reduced
 * motion); pass `drawn` to drive the trace yourself.
 */
function Check({ drawn, size = 16 }: { drawn?: boolean; size?: number }) {
  return (
    <svg aria-hidden data-slot="check" width={size} height={size} viewBox="0 0 24 24">
      <path
        d="M4 12.5 L9.5 18 L20 6"
        fill="none"
        stroke="currentColor"
        strokeWidth={1.75}
        strokeLinecap="square"
        pathLength={1}
        strokeDasharray={1}
        className={drawn === undefined ? `notchset-check-draw` : undefined}
        style={drawn === undefined ? undefined : { strokeDashoffset: drawn ? 0 : 1, transition: "stroke-dashoffset var(--notchset-check) var(--notchset-ease-travel)" }}
      />
    </svg>
  );
}

/** The scanner: five 1px ticks fading in turn while something works (static, centre lit, when motion is off). */
function Scanner({ height = 12 }: { height?: number }) {
  return (
    <span aria-hidden data-slot="scanner" className={cn(`notchset-scanner`, "inline-flex items-end gap-[2px]")} style={{ height }}>
      {[0.82, 0.66, 1, 0.66, 0.82].map((h, i) => (
        <span key={i} className="w-px bg-current" style={{ height: height * h, animationDelay: `${i * 140 - 700}ms` }} />
      ))}
    </span>
  );
}

// ---------------------------------------------------------------------------------------------
// Glyph flip: each character cycles through glyphs and lands at 110 + i·14ms, left to right
// ---------------------------------------------------------------------------------------------

const GLYPHS = "ABCDEFGHJKLMNPRSTUVWXYZ0123456789#/+=";
const STILL = new Set([" ", "·", "/", ".", ":"]);
const FLIP_CHARS = 24;

export function scramble(text: string, elapsed: number) {
  let out = "";
  for (let i = 0; i < text.length; i++) {
    const ch = text[i]!;
    // Characters past the 24th land with the 24th, so a long label flips as briefly as a short one.
    out += STILL.has(ch) || elapsed >= 110 + Math.min(i, FLIP_CHARS) * 14 ? ch : GLYPHS[(Math.floor(elapsed / 36) * 5 + i * 11) % GLYPHS.length];
  }
  return out;
}

/**
 * The text to show for `text`: when it changes, a few frames of glyphs that land left to right.
 * Runs on requestAnimationFrame only while a flip is active; the settled text is never state. Off
 * under reduced motion, inside data-motion="off" (pass the element) or with `off`.
 */
export function useGlyphFlip(text: string, { off = false, el }: { off?: boolean; el?: React.RefObject<Element | null> } = {}) {
  const [frame, setFrame] = React.useState<{ for: string; shown: string } | null>(null);
  const first = React.useRef(true);
  React.useEffect(() => {
    if (first.current) {
      first.current = false;
      return;
    }
    if (off || motionOff(el?.current)) return;
    let raf = 0;
    const t0 = performance.now();
    const end = 110 + Math.min(text.length, FLIP_CHARS) * 14 + 40;
    const step = (now: number) => {
      const elapsed = now - t0;
      if (elapsed >= end) {
        setFrame(null);
        return;
      }
      setFrame({ for: text, shown: scramble(text, elapsed) });
      raf = requestAnimationFrame(step);
    };
    raf = requestAnimationFrame(step);
    return () => cancelAnimationFrame(raf);
  }, [text, off, el]);
  // Turned off mid-flip, the label shows its text at once (the cancelled frame never lingers).
  return !off && frame && frame.for === text ? frame.shown : text;
}

/** A label that flips when its text changes; screen readers read the final text only. */
function FlipText({ children, off, className, ref: refProp, ...props }: Omit<React.ComponentProps<"span">, "children"> & { children: string; off?: boolean }) {
  const ref = React.useRef<HTMLSpanElement>(null);
  const refs = useComposedRefs<HTMLSpanElement>(refProp, ref);
  const shown = useGlyphFlip(children, { off, el: ref });
  return (
    <span {...props} ref={refs} data-slot="flip-text" className={cn("relative whitespace-nowrap", className)}>
      <span aria-hidden>{shown}</span>
      <span className="sr-only">{children}</span>
    </span>
  );
}

// ---------------------------------------------------------------------------------------------
// Sound: Notchset components announce cues; the page's beautiful-ui-sound layer (opt-in) plays them.
// ---------------------------------------------------------------------------------------------

/** The Notchset cues, in the shared sound layer's names (played in the mechanical voice). */
export const NOTCHSET_CUES = { tap: "tap", latch: "lock", signal: "destructive", confirm: "halt", done: "success", tick: "tick" } as const;
export type NotchsetCue = keyof typeof NOTCHSET_CUES;

export function playCue(el: Element | null, cue: NotchsetCue) {
  if (!el || typeof CustomEvent === "undefined" || el.closest('[data-sound="off"]')) return;
  el.dispatchEvent(new CustomEvent("beautiful-ui:sound", { bubbles: true, detail: { cue: NOTCHSET_CUES[cue] } }));
}

// ---------------------------------------------------------------------------------------------
// Shortcuts: "⌘↵" → "Meta+Enter Control+Enter" (aria-keyshortcuts)
// ---------------------------------------------------------------------------------------------

const KEY_NAMES: Record<string, string> = { "⌘": "Meta", "⌃": "Control", "⌥": "Alt", "⇧": "Shift", "↵": "Enter", "⏎": "Enter", "⎋": "Escape", "⌫": "Backspace", "⇥": "Tab", "␣": "Space" };

export function kbdToShortcut(kbd: string | undefined): string | undefined {
  if (!kbd) return undefined;
  const parts = [...kbd.replace(/\s+/g, "")].map((c) => KEY_NAMES[c] ?? c.toUpperCase());
  if (!parts.length) return undefined;
  const combo = parts.join("+");
  // ⌘ on a Mac is Ctrl elsewhere: announce both.
  return combo.includes("Meta") ? `${combo} ${combo.replace("Meta", "Control")}` : combo;
}

/**
 * Digits that roll: each digit is a 0–9 strip; the ones digit moves first and each digit to its left
 * 40ms later, counting digits only (620ms, a small overshoot). `delay` offsets the whole text. Other
 * characters (",", "$", "%", letters) sit still. Screen readers get the plain text. The one
 * implementation behind RollingNumber and the calendar's RollingLabel.
 */
export function DigitRoll({ text, height, delay = 0, className }: { text: string; height: number; delay?: number; className?: string }) {
  const chars = [...text];
  let k = 0;
  const order = chars.map((_, i) => (/\d/.test(chars[chars.length - 1 - i]!) ? k++ : 0)).reverse();
  return (
    <span className={cn("relative inline-flex flex-none overflow-hidden tabular-nums", className)} style={{ height, lineHeight: `${height}px` }}>
      <span className="sr-only">{text}</span>
      <span aria-hidden className="flex">
        {chars.map((d, i) =>
          /\d/.test(d) ? (
            <span
              key={chars.length - i}
              className="flex flex-col transition-transform duration-[620ms] ease-[cubic-bezier(.34,1.15,.5,1)] motion-reduce:transition-none"
              style={{ transform: `translateY(${-Number(d) * height}px)`, transitionDelay: `${delay + order[i]! * 40}ms` }}
            >
              {Array.from({ length: 10 }, (_, n) => (
                <span key={n} style={{ height }}>
                  {n}
                </span>
              ))}
            </span>
          ) : (
            <span key={`s${chars.length - i}`}>{d}</span>
          ),
        )}
      </span>
    </span>
  );
}

/** A number that rolls (DigitRoll at the readout's own size). `delay` offsets it (rows 60ms apart). */
function RollingNumber({ value, height = 32, delay = 0, className }: { value: string | number; height?: number; delay?: number; className?: string }) {
  return <DigitRoll text={String(value)} height={height} delay={delay} {...(className ? { className } : {})} />;
}

export { Check, Dot, FlipText, Legend, Node, Plated, RollingNumber, Scanner };
```

### lib/beautiful-ui/notchset/root.ts

```tsx
/*
 * Notchset's root attributes, server-safe (no client directive), so server components can spread
 * them too. Every Notchset root (and portalled popup) carries data-notchset (the motion policy's
 * scope), plays its own cues in the mechanical voice, and keeps the page's click layer out.
 */
export const NOTCHSET_ROOT = { "data-notchset": "", "data-sound": "none", "data-sound-voice": "analogue" } as const;

/** On every interactive element: it plays its own cues, so the page's click layer adds no tap. */
export const OWN_SOUND = { "data-sound": "none" } as const;
```

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