{ if (e.key === "Escape" && open) { e.stopPropagation(); setOpen(false); root.current?.querySelector("[data-ask]")?.focus(); } }} className="border border-solid border-foreground" > {state.kind === "sent" ? (

Sent. Ticket · we’ll reply to {email.trim()} within a business day.

) : (

setShaking(false)} className={cn("flex flex-col gap-2", shaking && "motion-safe:animate-[notchset-shake_var(--notchset-shake)_linear]")}> { setEmail(e.target.value); if (state.error) setState({ kind: "idle" }); }} placeholder="you@company.com" className={cn(inputClass, "h-[34px] px-2 font-sans")} />

{
                  setQuestion(e.target.value);
                  if (state.error) setState({ kind: "idle" });
                }}
                placeholder={search ? `About “${search}”…` : "What were you trying to do?"}
                className={cn(textareaClass, "resize-none p-2 font-sans")}
              />
            </div>
            <span className="flex gap-2">
              <button
                {...OWN_SOUND}
                type="submit"
                aria-busy={state.kind === "sending" || undefined}
                className={cn(`notchset-focus`, buttonVariants({ variant: "default", size: "default" }), "flex-1 justify-center gap-2 [--notchset-focus-inset:-3px]")}
              >
                {state.kind === "sending" ? (
                  <>
                    <Scanner height={8} /> SENDING
                  </>
                ) : (
                  "SEND"
                )}
              </button>
              <button
                {...OWN_SOUND}
                type="button"
                onClick={toggle}
                className={cn(`notchset-focus`, buttonVariants({ variant: "outline", size: "default" }), "[--notchset-focus-inset:-3px]")}
              >
                CANCEL
              </button>
            </span>
            <span id={hintId} aria-live="polite" className={cn(small, "tracking-[0.06em] whitespace-normal", state.error ? "text-[var(--notchset-signal-text,var(--destructive))]" : "text-muted-foreground")}>
              {state.error ?? "GOES TO SUPPORT · INCLUDES YOUR SEARCH"}
            </span>
          </form>
        )}
      </Fold>
    </div>
  );
}

return (
    <section {...NOTCHSET_ROOT} ref={root} data-slot="faq" aria-label={title} className={cn("@container box-border border border-solid border-foreground bg-background text-foreground", className)} {...props}>
      {/* Two columns (topics and Still stuck? on the left), one column under 640px with Still stuck? last. */}
      <div className="grid grid-cols-[minmax(0,220px)_minmax(0,1fr)] grid-rows-[auto_1fr] @max-[640px]:grid-cols-1 @max-[640px]:grid-rows-none">
        <div className="col-start-1 row-start-1 flex flex-col gap-4 border-0 border-e border-solid border-[var(--notchset-rule,var(--border))] pt-[22px] ps-5 pe-4 pb-4 @max-[640px]:border-e-0 @max-[640px]:pe-5 @max-[640px]:pb-0">
          <h2 className="m-0 text-[36px] leading-[0.88] font-extrabold uppercase [font-stretch:62%]">{title}</h2>
          <div
            role="tablist"
            aria-orientation="vertical"
            aria-label="Topic"
            onKeyDown={(e) => {
              const k = tabs.indexOf(cat);
              const step = e.key === "ArrowDown" || e.key === "ArrowRight" ? 1 : e.key === "ArrowUp" || e.key === "ArrowLeft" ? -1 : 0;
              if (e.key === "Home" || e.key === "End") {
                e.preventDefault();
                pickTab(tabs[e.key === "Home" ? 0 : tabs.length - 1]!, true);
              } else if (step) {
                e.preventDefault();
                pickTab(tabs[(k + step + tabs.length) % tabs.length]!, true);
              }
            }}
            className="flex flex-col border-0 border-t border-solid border-foreground @max-[640px]:flex-row @max-[640px]:overflow-x-auto"
          >
            {tabs.map((c) => {
              const on = c === cat;
              const n = items.filter((f) => inCat(f, c) && matches(f)).length;
              return (
                <button
                  key={c}
                  {...OWN_SOUND}
                  id={tabId(c)}
                  type="button"
                  role="tab"
                  aria-selected={on}
                  aria-controls={panelId}
                  tabIndex={on ? 0 : -1}
                  onClick={() => pickTab(c)}
                  className={cn(
                    `notchset-focus`,
                    "relative flex h-9 flex-none cursor-pointer items-center justify-between gap-3 border-0 border-b border-solid border-[var(--notchset-rule,var(--border))] ps-3 pe-1 text-start font-mono text-[10px] font-medium tracking-[0.1em] whitespace-nowrap transition-colors duration-(--notchset-fade) ease-(--notchset-ease-fade) [--notchset-focus-inset:-3px]",
                    on ? "bg-[var(--notchset-field,var(--muted))] text-foreground" : "bg-transparent text-muted-foreground hover:text-foreground",
                  )}
                >
                  <span aria-hidden className={cn("absolute inset-y-2 start-0 w-0.5 bg-foreground transition-[scale] duration-300 ease-(--notchset-ease-unfold)", on ? "scale-y-100" : "scale-y-0")} />
                  {c}
                  <RollingNumber value={n} height={12} className="font-normal text-muted-foreground" />
                </button>
              );
            })}
          </div>
        </div>
        <div className="col-start-2 row-span-2 row-start-1 flex min-w-0 flex-col gap-3 p-5 @max-[640px]:col-start-1 @max-[640px]:row-span-1 @max-[640px]:row-start-2">
          <div className="flex gap-2">
            <label className="box-border flex h-[38px] min-w-0 flex-1 items-center gap-2 border border-solid border-[var(--notchset-control-edge,var(--input))] bg-[var(--notchset-field,var(--background))] px-2.5 focus-within:border-foreground">
              <svg aria-hidden width="12" height="12" viewBox="0 0 13 13" className="flex-none">
                <circle cx="5.5" cy="5.5" r="4.2" fill="none" className="stroke-muted-foreground" strokeWidth="1.2" />
                <path d="M8.6 8.6 L12 12" className="stroke-muted-foreground" strokeWidth="1.2" />
              </svg>
              <input
                type="search"
                aria-label="Search questions"
                value={query}
                onChange={(e) => setQuery(e.target.value)}
                placeholder="Search, e.g. retention or SSO"
                spellCheck={false}
                className="min-w-0 flex-1 border-0 bg-transparent text-[14px] text-foreground outline-none placeholder:text-muted-foreground [&::-webkit-search-cancel-button]:hidden"
              />
              <span aria-live="polite" className={cn(small, "flex items-center gap-1 text-muted-foreground")}>
                <RollingNumber value={list.length} height={12} /> {list.length === 1 ? "RESULT" : "RESULTS"}
              </span>
            </label>
            <button
              {...OWN_SOUND}
              type="button"
              disabled={list.length === 0}
              onClick={toggleAll}
              className={cn(`notchset-focus`, buttonVariants({ variant: "outline", size: "lg" }), "[--notchset-focus-inset:-3px]")}
            >
              {allOpen ? "COLLAPSE ALL" : "EXPAND ALL"}
            </button>
          </div>
          <div id={panelId} role="tabpanel" aria-labelledby={tabId(cat)} className="border-0 border-t border-solid border-foreground">
            {list.length === 0 && (
              <div className="flex flex-col gap-1.5 py-6">
                <span className="text-[15px] font-semibold">No answers for “{query.trim()}”</span>
                <span className={cn(small, "tracking-[0.08em] text-muted-foreground")}>{onSubmitTicket ? "ASK US UNDER STILL STUCK? AND WE’LL ADD IT HERE" : "TRY ANOTHER WORD OR TOPIC"}</span>
              </div>
            )}
            {list.map(({ f, i }, k) => {
              const o = isOpen(i);
              const fb = feedback[i];
              const answerId = `${panelId}-a${i}`;
              return (
                <div key={f.q} className="border-0 border-b border-solid border-[var(--notchset-rule,var(--border))]">
                  <h3 className="m-0">
                    <button
                      {...OWN_SOUND}
                      type="button"
                      aria-expanded={o}
                      aria-controls={answerId}
                      onClick={() => toggle(i)}
                      className={cn(`notchset-focus`, "grid min-h-[52px] w-full cursor-pointer grid-cols-[28px_minmax(0,1fr)_16px] items-center gap-2.5 border-0 bg-transparent py-2.5 text-start text-foreground [--notchset-focus-inset:-3px]")}
                    >
                      <span className="font-mono text-[10px] text-muted-foreground">{String(k + 1).padStart(2, "0")}</span>
                      <span className={cn("text-[15px] leading-[1.35]", o ? "font-semibold" : "font-medium")}>
                        <Highlight text={f.q} q={q} />
                      </span>
                      <PlusMinus open={o} />
                    </button>
                  </h3>
                  <div id={answerId}>
                    <Fold open={o}>
                      <div className="flex flex-col gap-3 ps-[38px] pe-[26px] pb-4">
                        <div className="m-0 text-[14px] leading-[1.6] text-muted-foreground [text-wrap:pretty] [&_a]:text-foreground [&_a]:underline [&_a]:underline-offset-[3px] [&_code]:font-mono [&_code]:text-[12px] [&_code]:text-foreground">
                          {typeof f.a === "string" ? <Highlight text={f.a} q={q} /> : f.a}
                        </div>
                        {f.code && (
                          <pre className="m-0 self-start overflow-x-auto border border-solid border-[var(--notchset-rule,var(--border))] bg-[var(--notchset-field,var(--muted))] px-2.5 py-2 font-mono text-[11px] leading-[1.5]">
                            {f.code}
                          </pre>
                        )}
                        <div className={cn(small, "flex flex-wrap items-center gap-2 tracking-[0.08em] text-muted-foreground")}>
                          <span aria-live="polite">{fb === undefined ? "DID THIS ANSWER IT?" : fb ? "THANKS · GLAD IT HELPED" : "THANKS · WE’LL REWRITE THIS ANSWER"}</span>
                          {fb === undefined &&
                            ([true, false] as const).map((yes) => (
                              <button
                                key={String(yes)}
                                {...OWN_SOUND}
                                type="button"
                                onClick={() => {
                                  playCue(root.current, yes ? "done" : "tick");
                                  setFeedback((s) => ({ ...s, [i]: yes }));
                                  onFeedback?.(f, yes);
                                }}
                                className={cn(`notchset-focus`, buttonVariants({ variant: "outline", size: "xs" }), "[--notchset-focus-inset:-3px]")}
                              >
                                {yes ? "YES" : "NO"}
                              </button>
                            ))}
                        </div>
                      </div>
                    </Fold>
                  </div>
                </div>
              );
            })}
          </div>
        </div>
        <div className="col-start-1 row-start-2 flex flex-col justify-end border-0 border-e border-solid border-[var(--notchset-rule,var(--border))] ps-5 pe-4 pb-5 @max-[640px]:row-start-3 @max-[640px]:border-e-0 @max-[640px]:pe-5">
          {onSubmitTicket && <StillStuck search={query.trim()} onSubmitTicket={onSubmitTicket} />}
        </div>
      </div>
    </section>
  );
}

export { Faq };
```

### 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;
}

/** 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;
```

### lib/beautiful-ui/notchset/button-variants.ts

```tsx
import { cva } from "class-variance-authority";

/*
 * Notchset Button's variants, server-safe like shadcn's: call buttonVariants() from a Server Component
 * (links styled as buttons). The interactive Button lives in a client module.
 */

export const buttonVariants = cva(
  "group/button relative isolate inline-flex shrink-0 cursor-pointer items-center justify-center gap-(--b-gap) rounded-none border-0 font-mono font-medium tracking-[0.06em] whitespace-nowrap uppercase outline-none select-none transition-[background-color,color,translate,border-color] duration-[var(--notchset-fade),var(--notchset-fade),var(--notchset-key-up),var(--notchset-fade)] ease-[var(--notchset-ease-fade),var(--notchset-ease-fade),var(--notchset-ease-key-up),var(--notchset-ease-fade)] disabled:cursor-not-allowed disabled:opacity-40 aria-disabled:cursor-not-allowed aria-disabled:opacity-40 aria-busy:cursor-progress [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-(--b-ic) aria-pressed:bg-primary aria-pressed:text-primary-foreground data-[mode=armed]:bg-[var(--notchset-signal-text,var(--destructive))] data-[mode=armed]:text-primary-foreground data-[mode=hold]:translate-x-[2px] data-[mode=hold]:translate-y-[2px] data-[mode=hold]:duration-[var(--notchset-key-down)] data-[mode=hold]:ease-[var(--notchset-ease-key-down)]",
  {
    variants: {
      variant: {
        default: "bg-primary text-primary-foreground hover:bg-[var(--notchset-primary-hover,color-mix(in_oklab,var(--primary)_86%,var(--background)))] active:bg-[var(--notchset-primary-press,var(--primary))] [--b-tick:var(--notchset-tick-on-primary,color-mix(in_oklab,var(--primary-foreground)_34%,transparent))] [--b-kbd:var(--notchset-kbd-on-primary,color-mix(in_oklab,var(--primary-foreground)_45%,transparent))]",
        destructive:
          "bg-[var(--notchset-signal,var(--destructive))] text-[color:var(--notchset-on-signal,white)] hover:bg-[var(--notchset-signal-hover,var(--destructive))] active:bg-[var(--notchset-signal-press,var(--destructive))] [--b-tick:var(--notchset-tick-on-primary,color-mix(in_oklab,white_34%,transparent))] [--b-kbd:var(--notchset-kbd-on-signal,color-mix(in_oklab,black_40%,transparent))] [--notchset-focus-color:var(--notchset-signal-text,var(--destructive))]",
        outline: "border border-solid border-foreground bg-transparent text-foreground hover:bg-accent active:bg-[var(--notchset-tint-press,var(--accent))]",
        secondary: "bg-secondary text-secondary-foreground hover:bg-[var(--notchset-secondary-hover,var(--secondary))] active:bg-[var(--notchset-secondary-press,var(--secondary))]",
        signal:
          "border border-solid border-[var(--notchset-signal-text,var(--destructive))] bg-background text-[color:var(--notchset-signal-text,var(--destructive))] hover:bg-[var(--notchset-tint,color-mix(in_oklab,var(--destructive)_12%,var(--background)))] [--notchset-button-fill:color-mix(in_oklab,var(--notchset-signal,var(--destructive))_26%,var(--background))] [--notchset-button-meter:var(--notchset-signal,var(--destructive))] [--notchset-focus-color:var(--notchset-signal-text,var(--destructive))]",
        ghost: "bg-transparent text-foreground hover:bg-accent active:bg-[var(--notchset-tint-press,var(--accent))]",
        link: "h-auto min-w-0 justify-start bg-transparent px-0.5 pt-[3px] pb-1.5 text-foreground active:text-[var(--notchset-signal-text,var(--destructive))]",
        plate: "bg-primary text-primary-foreground hover:bg-[var(--notchset-primary-hover,color-mix(in_oklab,var(--primary)_86%,var(--background)))] active:translate-x-[2px] active:translate-y-[2px] active:duration-[var(--notchset-key-down)] active:ease-[var(--notchset-ease-key-down)]",
      },
      size: {
        // The market's heights (shadcn, and Kobra on it): XS 24, S 28, default 32, L 36. Labels are mono caps,
        // which read larger than the 14px sans those libraries use, so 12px (13px on L) matches them optically.
        // Same size names as shadcn, so it stays a drop-in. At least 44px tall on touch screens.
        default: "h-8 min-w-8 px-3 text-[12px] [--b-gap:8px] [--b-ic:16px] [--b-kh:18px] [--b-kfs:10px] pointer-coarse:min-h-11",
        xs: "h-6 min-w-6 px-2 text-[12px] [--b-gap:6px] [--b-ic:14px] [--b-kh:14px] [--b-kfs:10px] pointer-coarse:min-h-11",
        sm: "h-7 min-w-7 px-2.5 text-[12px] [--b-gap:7px] [--b-ic:16px] [--b-kh:16px] [--b-kfs:10px] pointer-coarse:min-h-11",
        lg: "h-9 min-w-9 px-4 text-[13px] [--b-gap:8px] [--b-ic:16px] [--b-kh:20px] [--b-kfs:10px] pointer-coarse:min-h-11",
        icon: "size-8 [--b-ic:16px]",
        "icon-xs": "size-6 [--b-ic:14px]",
        "icon-sm": "size-7 [--b-ic:16px]",
        "icon-lg": "size-9 [--b-ic:16px]",
      },
    },
    // The link's drawn rule lives in the Notchset foundation (a system class, kept out of the utilities).
    // The shared press (a 1px content dip) on every variant but plate, which moves whole onto its plate.
    compoundVariants: [
      { variant: "link", class: `notchset-link` },
      { variant: ["default", "destructive", "outline", "secondary", "signal", "ghost", "link"], class: `notchset-press` },
    ],
    defaultVariants: { variant: "default", size: "default" },
  },
);

export type ButtonVariant = NonNullable<Parameters<typeof buttonVariants>[0]>["variant"];
export type ButtonSize = NonNullable<Parameters<typeof buttonVariants>[0]>["size"];
```

### lib/beautiful-ui/notchset/field-classes.ts

```tsx
import { cn } from "@/lib/utils";

/*
 * Notchset field classes, server-safe (no client directive), so the bare Input and Textarea keep
 * their look in server components. The focus is a 2px ink trace drawn along the bottom edge from the
 * left, never a ring; invalid keeps a signal trace drawn; forced colors get a system outline.
 */

/** The focus trace and states, as utilities on the element itself (no wrapper needed). */
const TRACE =
  "bg-no-repeat [background-image:linear-gradient(var(--foreground),var(--foreground))] [background-position:left_bottom] [background-size:0_2px] focus:[background-size:100%_2px] aria-invalid:[background-image:linear-gradient(var(--notchset-signal,var(--destructive)),var(--notchset-signal,var(--destructive)))] aria-invalid:[background-size:100%_2px] forced-colors:focus:outline forced-colors:focus:outline-2 forced-colors:focus:outline-offset-2 forced-colors:focus:outline-[Highlight] transition-[border-color,background-size] duration-[140ms,200ms] ease-[linear,var(--notchset-ease-travel)] focus:duration-[140ms,300ms]";

export const inputClass = cn(
  "flex h-10 w-full min-w-0 border border-solid border-[var(--notchset-control-edge,var(--input))] bg-background px-3 py-0 font-mono text-[13px] tracking-[0.01em] text-foreground outline-none",
  "caret-[var(--notchset-signal,var(--destructive))] selection:bg-[var(--notchset-tint,color-mix(in_oklab,var(--destructive)_18%,transparent))] placeholder:text-muted-foreground",
  "hover:border-foreground focus:border-foreground aria-invalid:border-[var(--notchset-signal-text,var(--destructive))]",
  "disabled:cursor-not-allowed disabled:border-[var(--notchset-rule,var(--border))] disabled:opacity-40",
  "file:inline-flex file:h-full file:border-0 file:bg-transparent file:font-mono file:text-[11px] file:font-medium file:tracking-[0.07em] file:text-foreground file:uppercase",
  "pointer-coarse:h-11",
  TRACE,
);

export const textareaClass = cn(
  "flex field-sizing-content min-h-24 w-full border border-solid border-[var(--notchset-control-edge,var(--input))] bg-background px-3 pt-[11px] pb-1.5 font-sans text-sm leading-[1.5] text-foreground outline-none",
  "caret-[var(--notchset-signal,var(--destructive))] selection:bg-[var(--notchset-tint,color-mix(in_oklab,var(--destructive)_18%,transparent))] placeholder:text-muted-foreground",
  "hover:border-foreground focus:border-foreground aria-invalid:border-[var(--notchset-signal-text,var(--destructive))]",
  "disabled:cursor-not-allowed disabled:border-[var(--notchset-rule,var(--border))] disabled:opacity-40",
  TRACE,
);
```

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.