05Emergency bang button

<svg width="0" height="0" style="position:absolute" aria-hidden="true">
  <defs>
    <symbol id="ico-warning" viewBox="0 0 256 256" fill="currentColor"><g><path d="M224 91.55v72.9a8 8 0 0 1-2.34 5.66l-51.55 51.55a8 8 0 0 1-5.66 2.34h-72.9a8 8 0 0 1-5.66-2.34l-51.55-51.55a8 8 0 0 1-2.34-5.66v-72.9a8 8 0 0 1 2.34-5.66l51.55-51.55A8 8 0 0 1 91.55 32h72.9a8 8 0 0 1 5.66 2.34l51.55 51.55a8 8 0 0 1 2.34 5.66" opacity=".2"/><path d="M120 136V80a8 8 0 0 1 16 0v56a8 8 0 0 1-16 0m112-44.45v72.9a15.86 15.86 0 0 1-4.69 11.31l-51.55 51.55a15.86 15.86 0 0 1-11.31 4.69h-72.9a15.86 15.86 0 0 1-11.31-4.69l-51.55-51.55A15.86 15.86 0 0 1 24 164.45v-72.9a15.86 15.86 0 0 1 4.69-11.31l51.55-51.55A15.86 15.86 0 0 1 91.55 24h72.9a15.86 15.86 0 0 1 11.31 4.69l51.55 51.55A15.86 15.86 0 0 1 232 91.55m-16 0L164.45 40h-72.9L40 91.55v72.9L91.55 216h72.9L216 164.45ZM128 160a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></symbol>
  </defs>
</svg>
<main class="stage">
<div class="bb is-demo" id="bb">
  <p class="bb__hint">
    <svg class="bb__ico" aria-hidden="true"><use href="#ico-warning"/></svg>
    <span>Press it</span>
  </p>
  <div class="bb__scene">
    <div class="bb__panel">
      <span class="bb__lampWrap">
        <i class="bb__lamp"><i class="bb__lampGlow"></i></i>
        <span class="bb__lampText">Warning</span>
      </span>
      <div class="bb__well">
        <i class="bb__shadow"></i>
        <button class="bb__btn" id="btn" type="button" aria-pressed="false" aria-label="Emergency stop button">
          <i class="bb__dome"></i>
        </button>
      </div>
      <p class="bb__state">
        <span class="bb__stateIdle">Standby</span>
        <span class="bb__stateHit">Running</span>
      </p>
    </div>
  </div>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 비상 뱅 버튼 — 붉은 버튼을 누르면 원근 장면(perspective) 안으로 깊이 가라앉는다(translateZ).
// 가라앉으며 받침 그림자가 좁아지고(scaleX) 경고등이 켠다. 눌림은 색이 아니라 글자(대기/가동)와
// aria-pressed 로도 전달된다. 정적 경로는 transition 으로, 격자 미리보기(.is-demo)만 루프 키프레임.
// 사람이 버튼을 누르면 JS 가 .is-demo 를 뗀다.

$duration: $dur-quick;
$easing: $ease-spring;
$color: $error;

@include stage($stage-ink);

.bb { display: flex; flex-direction: column; align-items: center; gap: $sp-3; width: 100%; max-width: 340px; }
.bb__hint {
  display: flex; align-items: center; gap: $sp-1; margin: 0;
  font-weight: 700; font-size: clamp(10px, 2.8vw, 12px); color: $subject-cream;
}
.bb__ico { width: 16px; height: 16px; flex: 0 0 auto; color: $subject-blue-light; }

.bb__scene { display: flex; justify-content: center; }
.bb__panel {
  display: flex; flex-direction: column; align-items: center; gap: $sp-1;
  border-radius: $r-card; padding: $sp-2 $sp-4 $sp-3;
  background: linear-gradient(180deg, rgba($stage-paper, .5), rgba($stage-paper, 0) 30%), $subject-cream;
  box-shadow: $shadow-raised, inset 0 1px 0 rgba(255, 255, 255, .8), inset 0 -3px 0 rgba($subject-ink, .16);
}

.bb__lampWrap { display: inline-flex; align-items: center; gap: $sp-1; }
.bb__lamp {
  position: relative; width: 14px; height: 14px; border-radius: 50%;
  background: $error-soft; box-shadow: inset 0 2px 3px rgba($subject-ink, .4), inset 0 -1px 0 rgba(255, 255, 255, .7);
  transition: background $duration $easing, box-shadow $duration $easing;
}
.bb__lampGlow {
  position: absolute; inset: -4px; border-radius: 50%;
  background: radial-gradient(circle, rgba($color, .85), rgba($color, 0) 70%);
  opacity: 0;
}
.bb__lampText {
  font-weight: 800; font-size: clamp(9px, 2.4vw, 11px); line-height: 1.6; color: $subject-ink;
}
.bb.is-on .bb__lamp {
  background: $color;
  box-shadow: 0 0 0 2px rgba($color, .28), 0 0 14px 2px rgba($color, .65), inset 0 2px 3px rgba($subject-ink, .35);
}

// 우물 — 버튼이 들어앉은 받침. perspective 는 이 상자에 걸고 버튼은 직계 자식이어야 원근이 먹는다
.bb__well { position: relative; display: flex; justify-content: center; perspective: 600px; }
.bb__shadow {
  position: absolute; left: 50%; bottom: -8px; width: 92%; height: 14px;
  transform: translateX(-50%) scaleX(1); border-radius: 50%;
  background: rgba($subject-ink, .34);
  transition: transform $duration $easing, opacity $duration $easing;
}
.bb__btn {
  position: relative; display: block; width: clamp(88px, 24vw, 108px); height: clamp(64px, 17vw, 80px);
  border: 0; border-radius: 50%; padding: 0; cursor: pointer; touch-action: manipulation;
  background:
    radial-gradient(120% 90% at 32% 22%, rgba(255, 255, 255, .5), rgba(255, 255, 255, 0) 46%),
    radial-gradient(140% 120% at 50% 118%, rgba($subject-ink, .5), rgba($subject-ink, 0) 52%),
    $color;
  box-shadow: 0 10px 0 rgba($subject-ink, .3), 0 14px 18px rgba($subject-ink, .35), inset 0 2px 3px rgba(255, 255, 255, .55), inset 0 -4px 6px rgba($subject-ink, .45);
  transition: transform $duration $easing, box-shadow $duration $easing;
}
.bb__btn:focus-visible { outline: 2px solid $subject-blue-light; outline-offset: 3px; }
.bb__dome {
  position: absolute; left: 50%; top: 14%; width: 58%; height: 58%;
  transform: translateX(-50%); border-radius: 50%;
  background: radial-gradient(100% 100% at 34% 26%, rgba(255, 255, 255, .65), rgba(255, 255, 255, 0) 55%);
}
// 눌림 — 장면 깊이로 가라앉는다. 받침 그림자는 같은 타이밍에 좁아진다
.bb__btn[aria-pressed="true"] { transform: translateZ(-120px); }
.bb.is-on .bb__shadow { transform: translateX(-50%) scaleX(.55); opacity: .55; }

.bb__state { margin: $sp-2 0 0; font-weight: 800; font-size: clamp(11px, 3vw, 13px); line-height: 1.6; }
.bb__stateIdle { color: $subject-ink; }
.bb__stateHit { color: $error; }
.bb:not(.is-on) .bb__stateHit { display: none; }
.bb.is-on .bb__stateIdle { display: none; }

// ── 미리보기 루프(2초 한 바퀴) ─────────────────────────────────────
// 가라앉기(6% 부터) → 점등 hold 와 경고등 깜빡임 → 46% 부터 돌아온다(복귀는 90% 안에).
// 상태 글자 교체는 steps(1,end) 로 한 프레임에 컷 — 반투명 유령 프레임을 만들지 않는다.
.bb.is-demo .bb__btn {
  animation-name: bbSink; animation-duration: $dur-loop;
  animation-timing-function: $easing; animation-iteration-count: infinite;
}
.bb.is-demo .bb__shadow {
  animation-name: bbShadow; animation-duration: $dur-loop;
  animation-timing-function: $easing; animation-iteration-count: infinite;
}
.bb.is-demo .bb__lampGlow {
  animation-name: bbBlink; animation-duration: $dur-loop;
  animation-timing-function: linear; animation-iteration-count: infinite;
}
.bb.is-demo .bb__stateIdle, .bb.is-demo .bb__stateHit { display: inline; }
.bb.is-demo .bb__stateIdle {
  animation-name: bbIdleCut; animation-duration: $dur-loop;
  animation-timing-function: steps(1, end); animation-iteration-count: infinite;
}
.bb.is-demo .bb__stateHit {
  animation-name: bbHitCut; animation-duration: $dur-loop;
  animation-timing-function: steps(1, end); animation-iteration-count: infinite;
}
@keyframes bbSink {
  0%, 6%   { transform: translateZ(0); }
  14%, 46% { transform: translateZ(-120px); }
  54%, 100% { transform: translateZ(0); }
}
@keyframes bbShadow {
  0%, 6%   { transform: translateX(-50%) scaleX(1); opacity: 1; }
  14%, 46% { transform: translateX(-50%) scaleX(.55); opacity: .55; }
  54%, 100% { transform: translateX(-50%) scaleX(1); opacity: 1; }
}
@keyframes bbBlink {
  0%, 9%   { opacity: 0; }
  12%      { opacity: .45; }
  18%      { opacity: 1; }
  24%      { opacity: .5; }
  30%      { opacity: 1; }
  36%      { opacity: .5; }
  42%      { opacity: 1; }
  47%, 100% { opacity: 0; }
}
@keyframes bbIdleCut {
  0%, 13%  { opacity: 1; }
  14%, 46% { opacity: 0; }
  47%, 100% { opacity: 1; }
}
@keyframes bbHitCut {
  0%, 13%  { opacity: 0; }
  14%, 46% { opacity: 1; }
  47%, 100% { opacity: 0; }
}

@media (max-width: 340px) {
  .bb { gap: $sp-2; }
  .bb__panel { padding: $sp-2 $sp-3; gap: 0; }
  .bb__shadow { bottom: -4px; height: 10px; }
}

// reduce 에서는 루프를 끄고 버튼이 올라온 정적 한 장으로 둔다
@media (prefers-reduced-motion: reduce) {
  .bb.is-demo .bb__btn { animation: none !important; }
  .bb.is-demo .bb__shadow { animation: none !important; }
  .bb.is-demo .bb__lampGlow { animation: none !important; opacity: 0 !important; }
  .bb.is-demo .bb__stateIdle { animation: none !important; }
  .bb.is-demo .bb__stateHit { animation: none !important; }
  .bb__btn { transition: none !important; }
  .bb__shadow { transition: none !important; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.bb {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 340px;
}

.bb__hint {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  font-weight: 700;
  font-size: clamp(10px, 2.8vw, 12px);
  color: #fff7e6;
}

.bb__ico {
  width: 16px;
  height: 16px;
  flex: 0 0 auto;
  color: #5b8cf8;
}

.bb__scene {
  display: flex;
  justify-content: center;
}

.bb__panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  border-radius: 16px;
  padding: 8px 16px 12px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0) 30%), #fff7e6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32), inset 0 1px 0 rgba(255, 255, 255, 0.8), inset 0 -3px 0 rgba(23, 20, 26, 0.16);
}

.bb__lampWrap {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.bb__lamp {
  position: relative;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #ffe0d8;
  box-shadow: inset 0 2px 3px rgba(23, 20, 26, 0.4), inset 0 -1px 0 rgba(255, 255, 255, 0.7);
  transition: background 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.bb__lampGlow {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(194, 54, 26, 0.85), rgba(194, 54, 26, 0) 70%);
  opacity: 0;
}

.bb__lampText {
  font-weight: 800;
  font-size: clamp(9px, 2.4vw, 11px);
  line-height: 1.6;
  color: #17141a;
}

.bb.is-on .bb__lamp {
  background: #c2361a;
  box-shadow: 0 0 0 2px rgba(194, 54, 26, 0.28), 0 0 14px 2px rgba(194, 54, 26, 0.65), inset 0 2px 3px rgba(23, 20, 26, 0.35);
}

.bb__well {
  position: relative;
  display: flex;
  justify-content: center;
  perspective: 600px;
}

.bb__shadow {
  position: absolute;
  left: 50%;
  bottom: -8px;
  width: 92%;
  height: 14px;
  transform: translateX(-50%) scaleX(1);
  border-radius: 50%;
  background: rgba(23, 20, 26, 0.34);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.bb__btn {
  position: relative;
  display: block;
  width: clamp(88px, 24vw, 108px);
  height: clamp(64px, 17vw, 80px);
  border: 0;
  border-radius: 50%;
  padding: 0;
  cursor: pointer;
  touch-action: manipulation;
  background: radial-gradient(120% 90% at 32% 22%, rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0) 46%), radial-gradient(140% 120% at 50% 118%, rgba(23, 20, 26, 0.5), rgba(23, 20, 26, 0) 52%), #c2361a;
  box-shadow: 0 10px 0 rgba(23, 20, 26, 0.3), 0 14px 18px rgba(23, 20, 26, 0.35), inset 0 2px 3px rgba(255, 255, 255, 0.55), inset 0 -4px 6px rgba(23, 20, 26, 0.45);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.bb__btn:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 3px;
}

.bb__dome {
  position: absolute;
  left: 50%;
  top: 14%;
  width: 58%;
  height: 58%;
  transform: translateX(-50%);
  border-radius: 50%;
  background: radial-gradient(100% 100% at 34% 26%, rgba(255, 255, 255, 0.65), rgba(255, 255, 255, 0) 55%);
}

.bb__btn[aria-pressed=true] {
  transform: translateZ(-120px);
}

.bb.is-on .bb__shadow {
  transform: translateX(-50%) scaleX(0.55);
  opacity: 0.55;
}

.bb__state {
  margin: 8px 0 0;
  font-weight: 800;
  font-size: clamp(11px, 3vw, 13px);
  line-height: 1.6;
}

.bb__stateIdle {
  color: #17141a;
}

.bb__stateHit {
  color: #c2361a;
}

.bb:not(.is-on) .bb__stateHit {
  display: none;
}

.bb.is-on .bb__stateIdle {
  display: none;
}

.bb.is-demo .bb__btn {
  animation-name: bbSink;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}

.bb.is-demo .bb__shadow {
  animation-name: bbShadow;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
}

.bb.is-demo .bb__lampGlow {
  animation-name: bbBlink;
  animation-duration: 2s;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
}

.bb.is-demo .bb__stateIdle, .bb.is-demo .bb__stateHit {
  display: inline;
}

.bb.is-demo .bb__stateIdle {
  animation-name: bbIdleCut;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

.bb.is-demo .bb__stateHit {
  animation-name: bbHitCut;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes bbSink {
  0%, 6% {
    transform: translateZ(0);
  }
  14%, 46% {
    transform: translateZ(-120px);
  }
  54%, 100% {
    transform: translateZ(0);
  }
}
@keyframes bbShadow {
  0%, 6% {
    transform: translateX(-50%) scaleX(1);
    opacity: 1;
  }
  14%, 46% {
    transform: translateX(-50%) scaleX(0.55);
    opacity: 0.55;
  }
  54%, 100% {
    transform: translateX(-50%) scaleX(1);
    opacity: 1;
  }
}
@keyframes bbBlink {
  0%, 9% {
    opacity: 0;
  }
  12% {
    opacity: 0.45;
  }
  18% {
    opacity: 1;
  }
  24% {
    opacity: 0.5;
  }
  30% {
    opacity: 1;
  }
  36% {
    opacity: 0.5;
  }
  42% {
    opacity: 1;
  }
  47%, 100% {
    opacity: 0;
  }
}
@keyframes bbIdleCut {
  0%, 13% {
    opacity: 1;
  }
  14%, 46% {
    opacity: 0;
  }
  47%, 100% {
    opacity: 1;
  }
}
@keyframes bbHitCut {
  0%, 13% {
    opacity: 0;
  }
  14%, 46% {
    opacity: 1;
  }
  47%, 100% {
    opacity: 0;
  }
}
@media (max-width: 340px) {
  .bb {
    gap: 8px;
  }
  .bb__panel {
    padding: 8px 12px;
    gap: 0;
  }
  .bb__shadow {
    bottom: -4px;
    height: 10px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .bb.is-demo .bb__btn {
    animation: none !important;
  }
  .bb.is-demo .bb__shadow {
    animation: none !important;
  }
  .bb.is-demo .bb__lampGlow {
    animation: none !important;
    opacity: 0 !important;
  }
  .bb.is-demo .bb__stateIdle {
    animation: none !important;
  }
  .bb.is-demo .bb__stateHit {
    animation: none !important;
  }
  .bb__btn {
    transition: none !important;
  }
  .bb__shadow {
    transition: none !important;
  }
}

(function () {
  var root = document.getElementById('bb');
  var btn = document.getElementById('btn');
  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    var on = btn.getAttribute('aria-pressed') === 'true';
    btn.setAttribute('aria-pressed', on ? 'false' : 'true');
    root.classList.toggle('is-on', !on);
  });
})();

// BangButton — vanilla 판(run/013/demo/05-skeuo-bang-button) 의 React 포트.
// 누르면 원근 장면 안으로 translateZ 깊이 가라앉고 받침 그림자가 좁아지며 경고등이 켠다.
// 눌림은 aria-pressed 와 글자(대기/가동) 둘로 전달된다. 값·타이밍은 vanilla 와 같다.
import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./BangButton.module.scss";

export type BangButtonProps = {
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

const HINT = "눌러 보세요";
const ARIA_LABEL = "비상 정지 버튼";
const LAMP_TEXT = "경고";
const STATE_IDLE = "대기";
const STATE_HIT = "가동";

export default function BangButton({
  duration = 220,
  easing = "cubic-bezier(.2, .8, .2, 1)",
  color = "#c2361a",
}: BangButtonProps) {
  const [on, setOn] = useState(false);
  const [demo, setDemo] = useState(true);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  function press() {
    setDemo(false);
    setOn((v) => !v);
  }

  const cls = [styles.root, demo ? styles.isDemo : "", on ? styles.isOn : ""].filter(Boolean).join(" ");

  return (
    <main className={styles.stage}>
      <svg width="0" height="0" style={{ position: "absolute" }} aria-hidden="true">
        <defs>
          <symbol id="ico-warning" viewBox="0 0 256 256" fill="currentColor"><g><path d="M224 91.55v72.9a8 8 0 0 1-2.34 5.66l-51.55 51.55a8 8 0 0 1-5.66 2.34h-72.9a8 8 0 0 1-5.66-2.34l-51.55-51.55a8 8 0 0 1-2.34-5.66v-72.9a8 8 0 0 1 2.34-5.66l51.55-51.55A8 8 0 0 1 91.55 32h72.9a8 8 0 0 1 5.66 2.34l51.55 51.55a8 8 0 0 1 2.34 5.66" opacity=".2"/><path d="M120 136V80a8 8 0 0 1 16 0v56a8 8 0 0 1-16 0m112-44.45v72.9a15.86 15.86 0 0 1-4.69 11.31l-51.55 51.55a15.86 15.86 0 0 1-11.31 4.69h-72.9a15.86 15.86 0 0 1-11.31-4.69l-51.55-51.55A15.86 15.86 0 0 1 24 164.45v-72.9a15.86 15.86 0 0 1 4.69-11.31l51.55-51.55A15.86 15.86 0 0 1 91.55 24h72.9a15.86 15.86 0 0 1 11.31 4.69l51.55 51.55A15.86 15.86 0 0 1 232 91.55m-16 0L164.45 40h-72.9L40 91.55v72.9L91.55 216h72.9L216 164.45ZM128 160a12 12 0 1 0 12 12a12 12 0 0 0-12-12"/></g></symbol>
        </defs>
      </svg>
      <div className={cls} style={vars}>
        <p className={styles.hint}>
          <svg className={styles.ico} aria-hidden="true"><use href="#ico-warning" /></svg>
          <span>{HINT}</span>
        </p>
        <div className={styles.scene}>
          <div className={styles.panel}>
            <span className={styles.lampWrap}>
              <i className={styles.lamp}><i className={styles.lampGlow} /></i>
              <span className={styles.lampText}>{LAMP_TEXT}</span>
            </span>
            <div className={styles.well}>
              <i className={styles.shadow} />
              <button className={styles.btn} type="button" aria-pressed={on} aria-label={ARIA_LABEL} onClick={press}>
                <i className={styles.dome} />
              </button>
            </div>
            <p className={styles.state}>
              <span className={styles.stateIdle}>{STATE_IDLE}</span>
              <span className={styles.stateHit}>{STATE_HIT}</span>
            </p>
          </div>
        </div>
      </div>
    </main>
  );
}