# Site Footer (Notchset): prompt.md (v1.0.0)

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

A marketing site's footer in three layouts: columns (brand, a release-notes signup, link columns and a status row with a 60-day uptime strip and a data-region switch), minimal (one row with a status pill), and wordmark (the columns over a giant wordmark whose letters rise in turn).

## 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/blocks/site-footer.tsx`; shared code: `lib/beautiful-ui/notchset/instrument.tsx`, `lib/beautiful-ui/notchset/root.ts`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `segmented-control`, `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: `SiteFooter`, 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-signal`, `--notchset-sweep-to`, `--notchset-travel`). Never add Tailwind colour classes inside the component.

```tsx
import { SiteFooter } from "@/components/ui/notchset/blocks/site-footer";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `SiteFooter` | `site-footer` | The footer, in one of three layouts. |

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/blocks/site-footer.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
- footer, site footer, marketing footer, status page link, uptime, newsletter footer, data region, wordmark footer, Notchset
- The bottom of a marketing or docs site
- A product that wants its status and uptime one glance away

### Not when
- Inside an app's workspace: use the App Shell's own footer areas
- A single legal line is enough: a plain row reads faster

## Mistakes
- Point status at a real status page and keep the days honest: a strip that's always green stops meaning anything
- Persist the region choice if links follow it

## Usage

```tsx
import { SiteFooter } from "@/components/ui/notchset/blocks/site-footer";

export function Footer() {
  return (
    <SiteFooter
      brand={{ name: "Relay", href: "/" }}
      tagline="Trace, test and ship AI agents."
      columns={[
        { title: "PRODUCT", links: [{ label: "Traces", href: "/traces" }, { label: "Pricing", href: "/pricing" }] },
        { title: "COMPANY", links: [{ label: "Careers", href: "/careers", badge: "4 OPEN" }] },
      ]}
      legal={[{ label: "Privacy", href: "/privacy" }, { label: "Terms", href: "/terms" }]}
      copyright="© 2026 RELAY LABS"
      status={{ label: "ALL SYSTEMS NORMAL", href: "https://status.relay.dev" }}
      signup={{
        title: "RELEASE NOTES, ONCE A MONTH",
        note: "ONE EMAIL A MONTH · UNSUBSCRIBE ANYTIME",
        success: "SUBSCRIBED · CHECK YOUR INBOX",
        onSubscribe: (email) => fetch("/api/newsletter", { method: "POST", body: JSON.stringify({ email }) }).then((r) => { if (!r.ok) throw new Error(); }),
      }}
    />
  );
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `variant` | `"columns" \| "minimal" \| "wordmark"` |  | The layout. Default columns. |
| `brand` | `{ name, href, mark? }` |  | The wordmark and its home link. |
| `columns / links / legal / social` | `{ label, href, external?, badge? }[]` |  | Link columns ({ title, links }), the minimal row's links, the legal line and social links. |
| `status` | `{ label, href, days?, uptime? }` |  | The live status link; days is the uptime strip (oldest first, { label, incident? }). |
| `region` | `{ options, value, onValueChange }` |  | An optional data-region switch. |
| `signup` | `{ title, note, success, onSubscribe }` |  | Release notes; resolve to subscribe, reject to show the failure line. |
| `copyright / tagline / wordmark` | `string / ReactNode / string` |  | The copyright line, the brand's line, and the wordmark layout's letters. |

Full docs: https://beautiful-ui.dev/components/site-footer

## 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 |
|---|---|
| Tab | Links, the signup and the region switch in order |
| ← → | Move between data regions |

## Performance

- Plain markup and CSS transitions; the wordmark observes once and stops.

## Responsive

- Four columns become two under 760px and one under 440px (container width); the status row wraps.

## Motion inventory

| Interaction | What moves |
|---|---|
| Link hover | A 1px underline grows from the left (260ms glide) |
| Uptime day | The hovered bar grows (160ms settle) |
| Wordmark | Letters rise in turn when it scrolls into view (720ms, 70ms apart) and lift 6px under the pointer |
| Signup | The scanner while sending, then a check |

## Accessibility contract (preserve when editing)
- Each link column is a nav named by its title; the minimal row is one nav named Footer
- The signup has a label, marks invalid input (aria-invalid) and announces its result (aria-live)
- The uptime strip is one image with a summary (days, uptime, incidents); the hover readout is extra
- The wordmark is decorative (aria-hidden); external links open in a new tab

## Install

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

```bash
npx shadcn@latest add https://beautiful-ui.dev/r/site-footer.json
```

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

```bash
npx shadcn@latest add https://beautiful-ui.dev/r/radix-nova/site-footer.json
```

Or add the `@beautiful-ui` registry to components.json and run `npx shadcn@latest add @beautiful-ui/site-footer`: the CLI picks the build from your style.

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

## Source (Base UI build)

### components/ui/notchset/blocks/site-footer.tsx

```tsx
"use client";

import * as React from "react";
import { cn } from "@/lib/utils";
import { SegmentedControl } from "@/components/ui/notchset/segmented-control";
import { NOTCHSET_ROOT, OWN_SOUND, Scanner, motionOff, playCue } from "@/lib/beautiful-ui/notchset/instrument";

/*
 * Notchset Site Footer (a block, one file for both builds). A marketing site's footer in three layouts:
 * columns (brand, a release-notes signup, link columns, and a status row with a 60-day uptime strip and
 * a data-region switch), minimal (one row with the status pill), and wordmark (the columns over a giant
 * wordmark whose letters rise in turn). Links underline from the left on hover.
 */

export type FooterLink = { label: string; href: string; external?: boolean; badge?: string };
export type FooterColumn = { title: string; links: readonly FooterLink[] };
/** One day of the uptime strip, oldest first. An incident day is taller and in signal. */
export type UptimeDay = { label: string; incident?: string };

export type SiteFooterProps = Omit<React.ComponentProps<"footer">, "children"> & {
  variant?: "columns" | "minimal" | "wordmark";
  brand: { name: string; href: string; mark?: React.ReactNode };
  tagline?: React.ReactNode;
  columns?: readonly FooterColumn[];
  /** The minimal layout's links. */
  links?: readonly FooterLink[];
  legal?: readonly FooterLink[];
  social?: readonly FooterLink[];
  copyright: string;
  status?: { label: string; href: string; days?: readonly UptimeDay[]; uptime?: string };
  /** A data-region switch (US / EU): links can follow it. */
  region?: { options: readonly { value: string; label: string }[]; value: string; onValueChange: (value: string) => void };
  /** The release-notes signup; resolve to subscribe, reject to show the failure line. Hidden in the wordmark layout. */
  signup?: { title: string; note: string; success: string; onSubscribe: (email: string) => Promise<unknown> };
  /** The wordmark layout's giant letters (defaults to the brand name). */
  wordmark?: string;
};

const linkClass = cn(
  `notchset-focus`,
  "[--notchset-focus-inset:-3px] bg-[linear-gradient(currentColor,currentColor)] bg-[length:0%_1px] bg-[position:0_100%] bg-no-repeat pb-0.5 text-foreground no-underline transition-[background-size] duration-[260ms] ease-(--notchset-ease-glide) hover:bg-[length:100%_1px] focus-visible:bg-[length:100%_1px]",
);
const monoLabel = "font-mono text-[10px] tracking-[0.12em] uppercase";
const EMAIL = /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/;

function StatusPill({ status, bordered }: { status: NonNullable<SiteFooterProps["status"]>; bordered?: boolean }) {
  return (
    <a
      href={status.href}
      className={cn(
        `notchset-focus`,
        "[--notchset-focus-inset:-3px] flex items-center gap-2 font-mono text-[10px] font-medium tracking-[0.1em] whitespace-nowrap text-foreground uppercase no-underline",
        bordered && "h-7 border border-solid border-[var(--notchset-rule,var(--border))] px-2.5",
      )}
    >
      <span aria-hidden className="size-[7px] rounded-full bg-foreground motion-safe:animate-pulse" />
      {status.label}
    </a>
  );
}

function UptimeStrip({ days, uptime }: { days: readonly UptimeDay[]; uptime?: string }) {
  const [hover, setHover] = React.useState(-1);
  const incidents = days.filter((d) => d.incident).length;
  const day = days[hover];
  return (
    <div className="relative flex items-center gap-2.5" onMouseLeave={() => setHover(-1)}>
      <div role="img" aria-label={`Uptime for the last ${days.length} days${uptime ? `: ${uptime}` : ""}. ${incidents} incident${incidents === 1 ? "" : "s"}.`} className="flex h-[18px] items-center gap-[2px]">
        {days.map((d, i) => (
          <span
            key={d.label}
            onMouseEnter={() => setHover(i)}
            className={cn(
              "w-[3px] transition-[height,background-color] duration-[160ms,var(--notchset-fade)] ease-[var(--notchset-ease-settle),var(--notchset-ease-fade)]",
              d.incident ? "bg-[var(--notchset-signal,var(--destructive))]" : hover === i ? "bg-foreground" : "bg-[var(--notchset-control-edge,var(--input))]",
            )}
            style={{ height: hover === i ? 18 : d.incident ? 14 : 10 }}
          />
        ))}
      </div>
      {uptime && <span className="font-mono text-[10px] tracking-[0.06em] whitespace-nowrap text-muted-foreground">{uptime}</span>}
      {day && (
        <span
          aria-hidden
          className={cn(
            "pointer-events-none absolute bottom-[calc(100%+8px)] start-0 z-10 border border-solid bg-background px-2 py-1 font-mono text-[10px] tracking-[0.06em] whitespace-nowrap",
            day.incident ? "border-[var(--notchset-signal,var(--destructive))] text-[var(--notchset-signal-text,var(--destructive))]" : "border-foreground text-foreground",
          )}
        >
          {day.label} · {day.incident ?? "NO INCIDENTS"}
        </span>
      )}
    </div>
  );
}

function Signup({ signup }: { signup: NonNullable<SiteFooterProps["signup"]> }) {
  const [email, setEmail] = React.useState("");
  const [state, setState] = React.useState<{ kind: "idle" | "sending" | "done" | "error" | "failed"; message?: string }>({ kind: "idle" });
  const form = React.useRef<HTMLFormElement>(null);
  const submit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (state.kind === "sending") return;
    const value = email.trim();
    if (!EMAIL.test(value)) {
      playCue(form.current, "signal");
      setState({ kind: "error", message: value ? "THAT EMAIL LOOKS INCOMPLETE" : "ENTER AN EMAIL FIRST" });
      return;
    }
    setState({ kind: "sending" });
    try {
      await signup.onSubscribe(value);
      playCue(form.current, "done");
      setEmail("");
      setState({ kind: "done" });
    } catch {
      playCue(form.current, "signal");
      setState({ kind: "failed", message: "COULDN’T REACH THE SERVER · TRY AGAIN" });
    }
  };
  const bad = state.kind === "error" || state.kind === "failed";
  return (
    <form ref={form} noValidate onSubmit={submit} className="mt-1.5 flex max-w-[340px] flex-col gap-1.5">
      <span className={monoLabel}>{signup.title}</span>
      <div className={cn("flex h-10 border border-solid bg-[var(--notchset-field,var(--background))]", bad ? "border-[var(--notchset-signal,var(--destructive))]" : "border-[var(--notchset-control-edge,var(--input))]")}>
        <input
          type="email"
          aria-label={signup.title}
          aria-invalid={bad || undefined}
          value={email}
          onChange={(e) => {
            setEmail(e.target.value);
            if (state.kind !== "sending") setState({ kind: "idle" });
          }}
          readOnly={state.kind === "sending"}
          placeholder="you@company.com"
          spellCheck={false}
          className="min-w-0 flex-1 border-0 bg-transparent px-3 text-[14px] text-foreground outline-none placeholder:text-muted-foreground"
        />
        <button {...OWN_SOUND} type="submit" aria-label="Subscribe" aria-busy={state.kind === "sending" || undefined} className={cn(`notchset-focus`, "[--notchset-focus-inset:-3px] flex w-10 flex-none cursor-pointer items-center justify-center border-0 bg-foreground font-mono text-[14px] text-background")}>
          {state.kind === "sending" ? <Scanner height={9} /> : state.kind === "done" ? "✓" : "→"}
        </button>
      </div>
      <span aria-live="polite" className={cn("font-mono text-[10px] tracking-[0.08em]", bad ? "text-[var(--notchset-signal-text,var(--destructive))]" : state.kind === "done" ? "text-foreground" : "text-muted-foreground")}>
        {state.kind === "done" ? signup.success : (state.message ?? signup.note)}
      </span>
    </form>
  );
}

function Wordmark({ text }: { text: string }) {
  const ref = React.useRef<HTMLDivElement>(null);
  const [shown, setShown] = React.useState(false);
  React.useEffect(() => {
    const el = ref.current;
    if (!el) return;
    if (motionOff(el) || typeof IntersectionObserver !== "function") return setShown(true);
    const io = new IntersectionObserver((entries) => entries.some((e) => e.isIntersecting) && (setShown(true), io.disconnect()), { threshold: 0.2 });
    io.observe(el);
    return () => io.disconnect();
  }, []);
  return (
    <div ref={ref} aria-hidden className="mb-[-0.12em] flex justify-between border-0 border-t border-solid border-[var(--notchset-rule,var(--border))] px-5 select-none">
      {[...text].map((ch, i) => (
        <span key={`${ch}${i}`} className="block overflow-hidden pt-3">
          <span
            // Letters rise in turn (720ms, 70ms apart) and lift 6px under the pointer.
            className="block translate-y-(--rise) text-[clamp(96px,22vw,240px)] leading-[0.82] font-extrabold uppercase transition-[translate] duration-[720ms] ease-(--notchset-ease-unfold) [font-stretch:62%] [transition-delay:var(--stagger)] hover:-translate-y-1.5 hover:duration-(--notchset-key-up) hover:[transition-delay:0ms]"
            style={{ "--rise": shown ? "0%" : "105%", "--stagger": `${i * 70}ms` } as React.CSSProperties}
          >
            {ch}
          </span>
        </span>
      ))}
    </div>
  );
}

function SiteFooter({ variant = "columns", brand, tagline, columns = [], links = [], legal = [], social = [], copyright, status, region, signup, wordmark, className, ...props }: SiteFooterProps) {
  const brandLink = (size: "s" | "l") => (
    <a href={brand.href} aria-label={`${brand.name} home`} className={cn(`notchset-focus`, "[--notchset-focus-inset:-4px] flex items-center gap-2 self-start text-foreground no-underline")}>
      {brand.mark}
      <span className={cn("font-extrabold uppercase [font-stretch:62%]", size === "s" ? "text-[17px]" : "text-[20px]")}>{brand.name}</span>
    </a>
  );
  return (
    <footer {...NOTCHSET_ROOT} data-slot="site-footer" data-variant={variant} className={cn("@container box-border overflow-hidden border border-solid border-foreground bg-background text-foreground", className)} {...props}>
      {variant === "minimal" ? (
        <div className="flex flex-wrap items-center justify-between gap-5 px-7 py-5">
          {brandLink("s")}
          {links.length > 0 && (
            <nav aria-label="Footer" className="flex flex-wrap gap-[18px]">
              {links.map((l) => (
                <a key={l.label} href={l.href} className={cn(linkClass, "text-[14px]")}>
                  {l.label}
                </a>
              ))}
            </nav>
          )}
          {status && <StatusPill status={status} bordered />}
          <span className="font-mono text-[10px] tracking-[0.08em] whitespace-nowrap text-muted-foreground">{copyright}</span>
        </div>
      ) : (
        <>
          <div className="grid grid-cols-[minmax(0,1.5fr)_repeat(3,minmax(0,1fr))] gap-8 px-7 pt-9 pb-7 @max-[760px]:grid-cols-2 @max-[440px]:grid-cols-1">
            <div className="flex min-w-0 flex-col gap-3.5 @max-[760px]:col-span-2 @max-[440px]:col-span-1">
              {brandLink("l")}
              {tagline && <span className="max-w-[300px] text-[14px] leading-6 text-muted-foreground">{tagline}</span>}
              {signup && variant !== "wordmark" && <Signup signup={signup} />}
            </div>
            {columns.map((col) => (
              <nav key={col.title} aria-label={col.title} className="flex min-w-0 flex-col gap-3">
                <span className={cn(monoLabel, "pb-1 text-muted-foreground")}>{col.title}</span>
                {col.links.map((l) => (
                  <span key={l.label} className="flex items-center gap-2">
                    <a href={l.href} {...(l.external ? { target: "_blank", rel: "noreferrer" } : {})} className={cn(linkClass, "text-[14px] whitespace-nowrap")}>
                      {l.label}
                    </a>
                    {l.external && (
                      <span aria-hidden className="font-mono text-[10px] text-muted-foreground">
                        ↗
                      </span>
                    )}
                    {l.badge && <span className="flex h-4 items-center border border-solid border-foreground px-[5px] font-mono text-[10px] font-medium tracking-[0.08em] whitespace-nowrap">{l.badge}</span>}
                  </span>
                ))}
              </nav>
            ))}
          </div>
          <div className="mx-7 flex flex-wrap items-center justify-between gap-[18px] border-0 border-t border-solid border-[var(--notchset-rule,var(--border))] pt-4 pb-[18px]">
            <span className="flex flex-wrap items-center gap-4 font-mono text-[10px] tracking-[0.08em] text-muted-foreground">
              <span className="whitespace-nowrap">{copyright}</span>
              {legal.map((l) => (
                <a key={l.label} href={l.href} className={cn(linkClass, "whitespace-nowrap uppercase")}>
                  {l.label}
                </a>
              ))}
            </span>
            <div className="flex flex-wrap items-center gap-3.5">
              {status && (
                <div className="flex flex-wrap items-center gap-2.5">
                  <StatusPill status={status} />
                  {status.days && <UptimeStrip days={status.days} {...(status.uptime ? { uptime: status.uptime } : {})} />}
                </div>
              )}
              {region && <SegmentedControl aria-label="Data region" size="sm" segment={44} options={region.options} value={region.value} onValueChange={region.onValueChange} />}
              {social.length > 0 && (
                <span className="flex gap-3">
                  {social.map((l) => (
                    <a key={l.label} href={l.href} target="_blank" rel="noreferrer" className={cn(linkClass, "font-mono text-[10px] font-medium tracking-[0.08em] whitespace-nowrap uppercase")}>
                      {l.label} ↗
                    </a>
                  ))}
                </span>
              )}
            </div>
          </div>
          {variant === "wordmark" && <Wordmark text={wordmark ?? brand.name} />}
        </>
      )}
    </footer>
  );
}

export { SiteFooter };
```

### 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://beautiful-ui.dev/r/notchset-foundation.json.
