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

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

A toast() call and a Toaster in Notchset: toasts stack without overlapping, newest at the bottom, three at a time, each with a node, a mono meta line, an Undo that sends its inverse, and a 2px countdown line that pauses while you hover.

## 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/toast.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: `Toaster`, `toast`, `useToasts`, 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 { Toaster, toast } from "@/components/ui/notchset/toast";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `Toaster` | `toaster` | The stack. |
| `toast` | `toast` | One notice. |

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/toast.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
- toast, toaster, notification, snackbar, undo, sonner, Notchset
- Confirming an action that just happened, with an Undo when it can be reversed
- In place of shadcn's Sonner: the same toast() call

### Not when
- Conditions that need attention until fixed: use Alert
- Errors that block work: show them where they happened

## Mistakes
- Place one Toaster: every toast() call shows in it

## Usage

```tsx
"use client";

import { Toaster, toast } from "@/components/ui/notchset/toast";
import { Button } from "@/components/ui/notchset/button";

// Once, in your root layout (inside <body>).
export function AppToaster() {
  return <Toaster />;
}

export function PromoteButton({ rollback }: { rollback: () => void }) {
  return (
    <Button
      onClick={() =>
        toast("Planner v14 is live", {
          meta: "PROD · 100% TRAFFIC",
          action: { label: "Undo", onClick: rollback, then: { title: "Rolled back to v13" } },
        })
      }
    >
      Promote v14
    </Button>
  );
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `toast(title, options)` | `{ meta?, tone?: 'default' \| 'warn', action?: { label, onClick?, then? }, duration? }` |  | Shows a toast; returns its id. `then` replaces it after the action (an Undo's inverse). |
| `toast.dismiss(id?)` | `function` |  | Dismiss one, or all. |
| `Toaster` | `{ max?, duration?, label?, dismissLabel?, hotkey? }` |  | Place once. 3 visible, 5000ms, Alt+T focuses the stack. |

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

## 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 |
|---|---|
| Alt+T | Focus the stack |
| Esc | Dismiss the focused toast |

## Performance

- One store for the page; each toast holds one timer, paused (not polled) while the stack is hovered.
- The countdown line is a CSS animation on transform; stacking moves are transforms.

## Responsive

- 340px, never wider than the screen less 32px; titles and meta truncate on one line each.

## Motion inventory

| Interaction | What moves |
|---|---|
| Enter | Rises 20px into place (420ms) as it fades in |
| Stack | Older toasts slide up 72px (420ms); the region grows (360ms) |
| Exit | Shrinks to .96 and fades (260ms) |
| Countdown | A 2px line runs out along the bottom over the toast's life; it keeps time with motion off |

## Accessibility contract (preserve when editing)
- A labelled region; each toast is a status (an alert when it warns)
- Hovering or focusing the stack pauses every countdown
- Alt+T moves focus to the newest toast; Esc dismisses the focused one
- Hidden toasts beyond the three visible are inert

## Install

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

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

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

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

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

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

## Source (Base UI build)

### components/ui/notchset/toast.tsx

```tsx
"use client";

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

import * as React from "react";
import { cn } from "@/lib/utils";
import { NOTCHSET_ROOT, OWN_SOUND, playCue, useComposedRefs } from "@/lib/beautiful-ui/notchset/instrument";

/*
 * Notchset Toast (no primitive, one file for both builds). A `toast()` call, like
 * sonner's, and a <Toaster /> to place once. Toasts stack without overlapping: newest at the bottom,
 * 64px each on a 72px pitch, at most three visible, older ones sliding up (420ms) as the region grows
 * (360ms). Each has an 11px node, a title, a mono meta line, an optional action (Undo replaces the
 * toast with its inverse) and a dismiss key, and a 2px countdown line along its bottom edge. Hovering
 * or focusing the stack pauses every countdown. Alt+T moves focus to the stack; Esc dismisses a toast.
 */

export type ToastTone = "default" | "warn";
export type ToastContent = { title: string; meta?: string; tone?: ToastTone };
export type ToastOptions = Omit<ToastContent, "title"> & {
  /** One action key; `then` is the toast that replaces this one after it runs (an Undo's inverse). */
  action?: { label: string; onClick?: () => void; then?: ToastContent };
  /** Milliseconds before it clears (5000). */
  duration?: number;
  id?: number;
};
// gen: one per push. A toast re-sent under the same id is a new generation: it restarts its
// lifetime, and a removal scheduled for the old one never takes the new one with it.
type ToastRecord = ToastContent & ToastOptions & { id: number; gen: number; out: boolean };

// ---------------------------------------------------------------------------------------------
// The store: one list for the page; every Toaster reads it.
// ---------------------------------------------------------------------------------------------

let records: ToastRecord[] = [];
let seq = 0;
let gens = 0;
const listeners = new Set<() => void>();
const EMPTY: ToastRecord[] = [];
const emit = () => listeners.forEach((l) => l());
const set = (next: ToastRecord[]) => {
  records = next;
  emit();
};

function push(input: ToastContent & ToastOptions) {
  // Automatic ids skip any id a caller has used, so the two never collide.
  let id = input.id;
  if (id === undefined) {
    do id = ++seq;
    while (records.some((t) => t.id === id));
  }
  // Keep a few beyond the visible three so older ones can slide out of sight, not vanish.
  set([...records.filter((t) => !t.out && t.id !== id), { ...input, id, gen: ++gens, out: false }].slice(-5));
  return id;
}

function dismiss(id?: number) {
  const going = records.filter((t) => !t.out && (id === undefined || t.id === id)).map((t) => t.gen);
  if (!going.length) return;
  set(records.map((t) => (going.includes(t.gen) ? { ...t, out: true } : t)));
  // The exit runs 260ms, then those generations leave the list (a replacement sent meanwhile stays).
  setTimeout(() => set(records.filter((t) => !going.includes(t.gen))), 260);
}

/** Show a toast. `toast("Planner v14 is live", { meta, tone, action, duration })`, or one object. */
function toast(title: string | (ToastContent & ToastOptions), options: ToastOptions = {}) {
  return push(typeof title === "string" ? { ...options, title } : title);
}
toast.dismiss = dismiss;

const subscribe = (l: () => void) => {
  listeners.add(l);
  return () => listeners.delete(l);
};

/** The toasts on screen now (not leaving), oldest first: for a count or a status line. */
function useToasts() {
  const list = React.useSyncExternalStore(
    subscribe,
    () => records,
    () => EMPTY,
  );
  return React.useMemo(() => list.filter((t) => !t.out), [list]);
}

// ---------------------------------------------------------------------------------------------
// The stack
// ---------------------------------------------------------------------------------------------

const PITCH = 72;
const HEIGHT = 64;

function Toaster({
  max: maxProp = 3,
  duration = 5000,
  label = "Notifications",
  dismissLabel = "Dismiss",
  hotkey = "t",
  className,
  ref,
  onPointerEnter,
  onPointerLeave,
  onFocus,
  onBlur,
  ...props
}: Omit<React.ComponentProps<"section">, "children"> & {
  /** Visible at once (3, at most 5: the store keeps five). */
  max?: number;
  /** Default life of a toast in ms (5000). */
  duration?: number;
  label?: string;
  dismissLabel?: string;
  /** Alt + this key focuses the stack ("t"); empty to turn it off. */
  hotkey?: string;
}) {
  const list = React.useSyncExternalStore(
    subscribe,
    () => records,
    () => EMPTY,
  );
  const max = Number.isFinite(maxProp) ? Math.min(5, Math.max(1, Math.trunc(maxProp))) : 3;
  const region = React.useRef<HTMLElement>(null);
  const refs = useComposedRefs<HTMLElement>(ref, region);
  // Hover and focus pause separately: leaving with the pointer while a toast holds focus keeps it paused.
  const [hovered, setHovered] = React.useState(false);
  const [focused, setFocused] = React.useState(false);
  const paused = hovered || focused;
  const live = list.filter((t) => !t.out);
  const n = Math.min(live.length, max);
  // Where focus was before Alt+T: it goes back there when the last focused toast leaves.
  const origin = React.useRef<HTMLElement | null>(null);
  const passFocus = React.useCallback(() => {
    const next = [...(region.current?.querySelectorAll<HTMLElement>("[data-slot=toast]:not([aria-hidden]):not([inert]) button") ?? [])].at(-1);
    (next ?? (origin.current?.isConnected ? origin.current : null))?.focus();
  }, []);

  // A new toast sounds once: a rise, or the signal for a warning.
  const lastSounded = React.useRef(0);
  React.useEffect(() => {
    const newest = live[live.length - 1];
    if (!newest || newest.id <= lastSounded.current) return;
    lastSounded.current = newest.id;
    playCue(region.current, newest.tone === "warn" ? "signal" : "tap");
  }, [live]);

  React.useEffect(() => {
    if (!hotkey) return;
    const onKey = (e: KeyboardEvent) => {
      if (e.altKey && e.code === `Key${hotkey.toUpperCase()}`) {
        e.preventDefault();
        // The newest toast still on show (not hidden past the visible limit, not leaving).
        const live = [...(region.current?.querySelectorAll<HTMLElement>("[data-slot=toast]:not([aria-hidden]):not([inert])") ?? [])];
        const target = live.at(-1)?.querySelector<HTMLElement>("button");
        if (!target) return;
        if (!region.current?.contains(document.activeElement)) origin.current = document.activeElement as HTMLElement | null;
        target.focus();
      }
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  }, [hotkey]);

  return (
    <section
      {...props}
      {...NOTCHSET_ROOT}
      ref={refs}
      aria-label={hotkey ? `${label} (Alt+${hotkey.toUpperCase()})` : label}
      data-slot="toaster"
      className={cn(
        "pointer-events-none fixed end-6 bottom-6 z-[100] w-[340px] max-w-[calc(100vw-32px)] transition-[height] duration-[360ms] ease-[var(--notchset-ease-unfold)]",
        className,
      )}
      style={{ height: n ? HEIGHT + (n - 1) * PITCH : 0 }}
      onPointerEnter={(e) => {
        onPointerEnter?.(e);
        setHovered(true);
      }}
      onPointerLeave={(e) => {
        onPointerLeave?.(e);
        setHovered(false);
      }}
      onFocus={(e) => {
        onFocus?.(e);
        setFocused(true);
      }}
      onBlur={(e) => {
        onBlur?.(e);
        if (!e.currentTarget.contains(e.relatedTarget as Node | null)) setFocused(false);
      }}
    >
      <ol className="m-0 list-none p-0">
        {list.map((t) => {
          const i = t.out ? -1 : live.length - 1 - live.findIndex((x) => x.id === t.id);
          return <ToastItem key={t.id} toast={t} index={i} hidden={i >= max} paused={paused} duration={t.duration ?? duration} dismissLabel={dismissLabel} onLeave={passFocus} />;
        })}
      </ol>
    </section>
  );
}

function ToastItem({ toast: t, index, hidden, paused, duration, dismissLabel, onLeave }: { toast: ToastRecord; index: number; hidden: boolean; paused: boolean; duration: number; dismissLabel: string; onLeave: () => void }) {
  const item = React.useRef<HTMLLIElement>(null);
  // Leaving (or hidden past the limit) while it holds focus: focus moves on before the toast goes inert.
  React.useLayoutEffect(() => {
    if ((t.out || hidden) && item.current?.contains(document.activeElement)) onLeave();
  }, [t.out, hidden, onLeave]);
  const warn = t.tone === "warn";
  // Where it sat when it began to leave: it fades out in place.
  const [lastIndex, setLastIndex] = React.useState(index);
  if (index >= 0 && index !== lastIndex) setLastIndex(index);
  const y = -(index >= 0 ? index : lastIndex) * PITCH;

  // The countdown: runs while not paused; a resume always leaves at least 1.2s.
  const [life, setLife] = React.useState({ remaining: duration, run: 0 });
  const started = React.useRef(0);
  const lifeRef = React.useRef(life);
  React.useEffect(() => {
    lifeRef.current = life;
  });
  // A new generation (the same id sent again with new content) starts a full life.
  const gen = React.useRef(t.gen);
  React.useEffect(() => {
    if (gen.current === t.gen) return;
    gen.current = t.gen;
    lifeRef.current = { remaining: duration, run: lifeRef.current.run + 1 };
    setLife(lifeRef.current);
  }, [t.gen, duration]);
  React.useEffect(() => {
    if (t.out) return;
    if (paused) return;
    started.current = performance.now();
    const timer = setTimeout(() => dismiss(t.id), lifeRef.current.remaining);
    return () => {
      clearTimeout(timer);
      const left = lifeRef.current.remaining - (performance.now() - started.current);
      // Paused (or reset): bank what's left, at least 1.2s, for the next run of the line.
      setLife((l) => ({ remaining: Math.max(1200, left), run: l.run + 1 }));
    };
  }, [paused, t.out, t.id, t.gen]);

  const act = () => {
    t.action?.onClick?.();
    dismiss(t.id);
    const then = t.action?.then;
    if (then) setTimeout(() => push({ ...then }), 120);
  };

  return (
    <li
      {...OWN_SOUND}
      ref={item}
      data-slot="toast"
      data-tone={warn ? "warn" : "default"}
      role={warn ? "alert" : "status"}
      aria-hidden={hidden || undefined}
      inert={hidden || t.out || undefined}
      tabIndex={-1}
      onKeyDown={(e) => {
        if (e.key === "Escape") dismiss(t.id);
      }}
      className={cn(
        "pointer-events-auto absolute inset-x-0 bottom-0 h-16 transition-[translate,opacity] duration-[420ms,200ms] ease-[cubic-bezier(.34,1.3,.5,1),linear] outline-none",
        hidden && "opacity-0",
      )}
      style={{ translate: `0 ${y}px`, zIndex: 10 - Math.max(0, index) }}
    >
      <div
        className={cn(
          "relative flex h-full items-center gap-3 border border-solid bg-background ps-3.5 pe-2 text-foreground",
          warn ? "border-[var(--notchset-signal-text,var(--destructive))]" : "border-foreground",
          t.out
            ? "motion-safe:animate-[notchset-toast-out_260ms_var(--notchset-ease-travel)_both]"
            : "motion-safe:animate-[notchset-fade-in_200ms_linear_both,notchset-toast-in_420ms_cubic-bezier(.34,1.3,.5,1)_both]",
        )}
      >
        <svg aria-hidden width="11" height="11" viewBox="0 0 11 11" className={cn("flex-none overflow-visible", warn ? "text-[var(--notchset-signal,var(--destructive))]" : "text-foreground")}>
          <circle cx="5.5" cy="5.5" r="4" fill="none" stroke="currentColor" strokeWidth="1" />
          <circle cx="5.5" cy="5.5" r="2.2" fill="currentColor" />
        </svg>
        <div className="flex min-w-0 flex-1 flex-col gap-1">
          <span data-slot="toast-title" className="truncate font-sans text-[13.5px] leading-[1.2] font-medium">
            {t.title}
          </span>
          {t.meta && (
            <span data-slot="toast-meta" className="truncate font-mono text-[10px] tracking-[0.06em] text-muted-foreground">
              {t.meta}
            </span>
          )}
        </div>
        {t.action && (
          <button
            type="button"
            onClick={act}
            className={cn(
              `notchset-focus`,
              "h-7 flex-none cursor-pointer border border-solid border-foreground bg-transparent px-[9px] font-mono text-[11px] font-medium tracking-[0.08em] text-foreground uppercase transition-[background-color] duration-(--notchset-fade) ease-(--notchset-ease-fade) hover:bg-accent",
            )}
          >
            {t.action.label}
          </button>
        )}
        <button
          type="button"
          aria-label={dismissLabel}
          onClick={() => dismiss(t.id)}
          className={cn(
            `notchset-focus`,
            "[--notchset-focus-inset:-3px] flex size-7 flex-none cursor-pointer items-center justify-center border-0 bg-transparent p-0 text-muted-foreground transition-[color] duration-(--notchset-fade) ease-(--notchset-ease-fade) hover:text-foreground pointer-coarse:size-11",
          )}
        >
          <svg aria-hidden width="9" height="9" viewBox="0 0 10 10">
            <path fill="none" d="M1.5 1.5 L8.5 8.5 M8.5 1.5 L1.5 8.5" stroke="currentColor" strokeWidth="1.3" />
          </svg>
        </button>
        {!t.out && (
          <span
            key={life.run}
            aria-hidden
            className={cn(
              `notchset-life`,
              "absolute start-0 -bottom-px h-0.5 w-full origin-left animate-[notchset-life_var(--notchset-life-ms)_linear_both] rtl:origin-right",
              warn ? "bg-[var(--notchset-signal,var(--destructive))]" : "bg-foreground",
            )}
            style={
              {
                "--notchset-life-ms": `${life.remaining}ms`,
                "--notchset-life-from": Math.min(1, life.remaining / duration),
                animationPlayState: paused ? "paused" : "running",
              } as React.CSSProperties
            }
          />
        )}
      </div>
    </li>
  );
}

export { Toaster, toast, useToasts };
```

### 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.
