01Power button with LED ring

<main class="stage">
<div class="pw is-demo" id="pw">
  <div class="pw__col">
  <div class="pw__assembly">
    <span class="pw__bezel" aria-hidden="true"></span>
    <span class="pw__groove" aria-hidden="true"></span>
    <button class="pw__cap" id="pwCap" type="button" role="switch" aria-checked="false" aria-label="Power">
      <svg class="pw__mark" viewBox="0 0 24 24" aria-hidden="true" focusable="false">
        <path d="M12 3v6" fill="none" stroke="currentColor" stroke-width="2.3" stroke-linecap="round"></path>
        <path d="M18.4 6.6a7.4 7.4 0 1 1-12.8 0" fill="none" stroke="currentColor" stroke-width="2.3" stroke-linecap="round"></path>
      </svg>
    </button>
    <span class="pw__led" aria-hidden="true"></span>
    <span class="pw__shade" aria-hidden="true"></span>
  </div>
  <p class="pw__state" role="status"><span class="pw__wordOn">On</span><span class="pw__wordOff">Off</span></p>
  </div>
</div>
</main>

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

// 전원 버튼과 LED 링 — 베벨 링·어두운 그루브·캡의 3중 동심원. 캡 중앙의 전원 기호(IEC 5009)는 음각.
// 누르면 캡이 안으로 들어가고 그루브 위쪽 그림자가 짙어진다. 놓으면 캡이 먼저 돌아오고($duration),
// LED 링은 그 뒤에 서서히 켜진다 — 비대칭 타이밍. 끌 때는 반대로 LED 가 먼저 꺼지고 캡이 돌아온다.
// 켜짐은 색만으로 말하지 않는다: 링의 빛·기호의 발색·상태 글자가 함께 바뀐다. role="switch" + aria-checked.
// 미리보기(.is-demo)는 눌림 → 복귀 → 점등 유지 → 재눌림 → 소등을 2초에 한 바퀴 돈다.

$duration: $dur-quick;
$easing: $ease-spring;
$color: $stage-yellow;

@include stage($stage-ink);

.pw { display: grid; place-items: center; width: 100%; }
.pw__col { display: flex; flex-direction: column; align-items: center; gap: $sp-3; }

// ── 버튼 어셈블리(베벨 링 · 그루브 · 캡 · LED 링) ────────────
.pw__assembly { position: relative; width: 150px; height: 150px; }

// 바깥 베벨 링 — 위에서 비치는 금속성 테두리와 6시 방향 소프트 드롭섀도
.pw__bezel {
  position: absolute; inset: 0; border-radius: 50%; pointer-events: none;
  background: linear-gradient(145deg, rgba($subject-cream, .38), rgba($subject-cream, .1) 42%, rgba($stage-ink, .9) 78%), $subject-ink;
  box-shadow: 0 22px 26px -8px rgba(0, 0, 0, .8), 0 2px 3px rgba($subject-cream, .18), inset 0 1px 0 rgba($subject-cream, .4);
}

// 어두운 그루브 링 — 캡이 들어가는 홈, 그림자로 깊이를 만든다
.pw__groove {
  position: absolute; inset: 12px; border-radius: 50%; pointer-events: none;
  background: linear-gradient(180deg, rgba(0, 0, 0, .85), rgba(0, 0, 0, .55));
  box-shadow: inset 0 4px 8px rgba(0, 0, 0, .9), inset 0 -1px 0 rgba($subject-cream, .14);
}

// 캡(지름 60%) — 실제 누르는 면. 전원 기호는 SVG 로 직접 그렸다(아이콘 세트에 없는 정밀 기호 예외)
.pw__cap {
  position: absolute; inset: 30px; z-index: 5;
  display: flex; align-items: center; justify-content: center;
  margin: 0; padding: 0; border: 0; border-radius: 50%; cursor: pointer;
  background: linear-gradient(180deg, rgba($subject-cream, .22), rgba($subject-cream, .02) 34%, rgba($stage-ink, .5) 88%), $subject-ink;
  box-shadow: 0 6px 10px rgba(0, 0, 0, .66), inset 0 1px 0 rgba($subject-cream, .3), inset 0 -2px 4px rgba(0, 0, 0, .6);
  transform: translateY(0) scale(1);
  transition: transform $duration $easing, box-shadow $duration $easing;
}
.pw__cap:active {
  transform: translateY(4px) scale(.98);
  box-shadow: 0 2px 4px rgba(0, 0, 0, .6), inset 0 1px 0 rgba($subject-cream, .22), inset 0 -2px 4px rgba(0, 0, 0, .6);
}
.pw__cap:focus-visible { outline: 2px solid $stage-yellow; outline-offset: 3px; }

// 전원 기호 — 꺼짐은 낮은 대비의 음각 회색, 켜지면 $color 로 밝아진다
.pw__mark { width: 34px; height: 34px; color: $tick-mute; transition: color $dur-quick $ease-out; }

// LED 링 — 그루브 위를 도는 빛. 켜질 때는 캡 복귀 뒤 $dur-quick 늦게 $dur-base 에 걸쳐 번지고,
// 꺼질 때는 지연 없이 빠르게 사그라든다(방향마다 transition 규칙을 다르게 둔 한 방향 트릭).
.pw__led {
  position: absolute; inset: 22px; z-index: 2; border-radius: 50%; pointer-events: none;
  box-shadow: inset 0 0 0 3px rgba($color, .14);
  transition: box-shadow $dur-quick $ease-out;
}

// 그루브 위쪽 내그림자 — 누르는 동안 짙어진다(캡보다 뒤에 두어 캡은 덮지 않는다)
.pw__shade {
  position: absolute; inset: 25px; z-index: 3; border-radius: 50%; pointer-events: none;
  box-shadow: inset 0 7px 9px rgba(0, 0, 0, .75);
  opacity: .3; transition: opacity $duration $easing;
}
.pw__cap:active ~ .pw__shade { opacity: .8; }

// ── 켜짐 상태 ────────────────────────────────────────────────
.pw.is-on .pw__led {
  box-shadow: inset 0 0 0 3px $color, 0 0 16px rgba($color, .6), 0 0 34px rgba($color, .28);
  transition: box-shadow $dur-base $ease-out $duration;
}
.pw.is-on .pw__mark { color: $color; transition: color $dur-base $ease-out $duration; }

// ── 상태 글자 ────────────────────────────────────────────────
.pw__state { position: relative; margin: 0; width: 60px; height: 16px; }
.pw__wordOn, .pw__wordOff {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: clamp(12px, 3vw, 14px); line-height: 1; color: $subject-cream;
}
.pw__wordOn { display: none; color: $stage-yellow; }
.pw.is-on .pw__wordOn { display: flex; }
.pw.is-on .pw__wordOff { display: none; }

// ── 미리보기 루프(2초 한 바퀴) ────────────────────────────────
// 캡 눌림은 transform 키프레임(움직임 축), LED 점등은 box-shadow·색 키프레임(상태 변화라 번지는 게 맞다).
.pw.is-demo .pw__cap {
  animation-name: pwPress; animation-duration: $dur-loop;
  animation-timing-function: $easing; animation-iteration-count: infinite;
}
@keyframes pwPress {
  0%, 6% { transform: translateY(0) scale(1); }
  11% { transform: translateY(4px) scale(.98); }
  16% { transform: translateY(0) scale(1); }
  57% { transform: translateY(0) scale(1); }
  62% { transform: translateY(4px) scale(.98); }
  68%, 100% { transform: translateY(0) scale(1); }
}
.pw.is-demo .pw__shade {
  animation-name: pwShade; animation-duration: $dur-loop;
  animation-timing-function: steps(1, end); animation-iteration-count: infinite;
}
@keyframes pwShade {
  0% { opacity: .3; }
  7% { opacity: .8; }
  16% { opacity: .3; }
  57% { opacity: .8; }
  68% { opacity: .3; }
  100% { opacity: .3; }
}
.pw.is-demo .pw__led {
  animation-name: pwLed; animation-duration: $dur-loop;
  animation-timing-function: ease; animation-iteration-count: infinite;
}
@keyframes pwLed {
  0%, 16% { box-shadow: inset 0 0 0 3px rgba($color, .14); }
  28%, 58% { box-shadow: inset 0 0 0 3px $color, 0 0 16px rgba($color, .6), 0 0 34px rgba($color, .28); }
  63%, 100% { box-shadow: inset 0 0 0 3px rgba($color, .14); }
}
.pw.is-demo .pw__mark {
  animation-name: pwMark; animation-duration: $dur-loop;
  animation-timing-function: ease; animation-iteration-count: infinite;
}
@keyframes pwMark {
  0%, 16% { color: $tick-mute; }
  28%, 58% { color: $color; }
  63%, 100% { color: $tick-mute; }
}
// 상태 글자는 steps(1, end) 컷 — 반투명하게 겹치는 유령 프레임이 생기지 않는다
.pw.is-demo .pw__wordOn { display: flex; opacity: 0; }
.pw.is-demo .pw__wordOff { opacity: 1; }
.pw.is-demo .pw__wordOn {
  animation-name: pwWordOn; animation-duration: $dur-loop;
  animation-timing-function: steps(1, end); animation-iteration-count: infinite;
}
@keyframes pwWordOn {
  0%, 18% { opacity: 0; }
  24% { opacity: 1; }
  60% { opacity: 0; }
  100% { opacity: 0; }
}
.pw.is-demo .pw__wordOff {
  animation-name: pwWordOff; animation-duration: $dur-loop;
  animation-timing-function: steps(1, end); animation-iteration-count: infinite;
}
@keyframes pwWordOff {
  0%, 18% { opacity: 1; }
  24% { opacity: 0; }
  60% { opacity: 1; }
  100% { opacity: 1; }
}

@media (max-width: 340px) {
  .pw__col { gap: $sp-2; }
  .pw__assembly { width: 118px; height: 118px; }
  .pw__groove { inset: 10px; }
  .pw__cap { inset: 24px; }
  .pw__led { inset: 18px; }
  .pw__shade { inset: 20px; }
  .pw__mark { width: 26px; height: 26px; }
  .pw__state { width: 48px; height: 14px; }
}

@media (prefers-reduced-motion: reduce) {
  .pw .pw__cap { transition: none !important; }
  .pw .pw__shade { transition: none !important; }
  .pw.is-demo .pw__cap { animation: none !important; transform: translateY(0) scale(1) !important; }
  .pw.is-demo .pw__shade { animation: none !important; opacity: .3 !important; }
  .pw.is-demo .pw__led { animation: none !important; }
  .pw.is-demo .pw__mark { animation: none !important; }
  .pw.is-demo .pw__wordOn { animation: none !important; opacity: 0 !important; }
  .pw.is-demo .pw__wordOff { animation: none !important; opacity: 1 !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);
}

.pw {
  display: grid;
  place-items: center;
  width: 100%;
}

.pw__col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.pw__assembly {
  position: relative;
  width: 150px;
  height: 150px;
}

.pw__bezel {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  pointer-events: none;
  background: linear-gradient(145deg, rgba(255, 247, 230, 0.38), rgba(255, 247, 230, 0.1) 42%, rgba(23, 20, 26, 0.9) 78%), #17141a;
  box-shadow: 0 22px 26px -8px rgba(0, 0, 0, 0.8), 0 2px 3px rgba(255, 247, 230, 0.18), inset 0 1px 0 rgba(255, 247, 230, 0.4);
}

.pw__groove {
  position: absolute;
  inset: 12px;
  border-radius: 50%;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0.85), rgba(0, 0, 0, 0.55));
  box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.9), inset 0 -1px 0 rgba(255, 247, 230, 0.14);
}

.pw__cap {
  position: absolute;
  inset: 30px;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  padding: 0;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  background: linear-gradient(180deg, rgba(255, 247, 230, 0.22), rgba(255, 247, 230, 0.02) 34%, rgba(23, 20, 26, 0.5) 88%), #17141a;
  box-shadow: 0 6px 10px rgba(0, 0, 0, 0.66), inset 0 1px 0 rgba(255, 247, 230, 0.3), inset 0 -2px 4px rgba(0, 0, 0, 0.6);
  transform: translateY(0) scale(1);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.pw__cap:active {
  transform: translateY(4px) scale(0.98);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.6), inset 0 1px 0 rgba(255, 247, 230, 0.22), inset 0 -2px 4px rgba(0, 0, 0, 0.6);
}

.pw__cap:focus-visible {
  outline: 2px solid #ffd23f;
  outline-offset: 3px;
}

.pw__mark {
  width: 34px;
  height: 34px;
  color: #9a93a6;
  transition: color 220ms ease-out;
}

.pw__led {
  position: absolute;
  inset: 22px;
  z-index: 2;
  border-radius: 50%;
  pointer-events: none;
  box-shadow: inset 0 0 0 3px rgba(255, 210, 63, 0.14);
  transition: box-shadow 220ms ease-out;
}

.pw__shade {
  position: absolute;
  inset: 25px;
  z-index: 3;
  border-radius: 50%;
  pointer-events: none;
  box-shadow: inset 0 7px 9px rgba(0, 0, 0, 0.75);
  opacity: 0.3;
  transition: opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.pw__cap:active ~ .pw__shade {
  opacity: 0.8;
}

.pw.is-on .pw__led {
  box-shadow: inset 0 0 0 3px #ffd23f, 0 0 16px rgba(255, 210, 63, 0.6), 0 0 34px rgba(255, 210, 63, 0.28);
  transition: box-shadow 300ms ease-out 220ms;
}

.pw.is-on .pw__mark {
  color: #ffd23f;
  transition: color 300ms ease-out 220ms;
}

.pw__state {
  position: relative;
  margin: 0;
  width: 60px;
  height: 16px;
}

.pw__wordOn, .pw__wordOff {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: clamp(12px, 3vw, 14px);
  line-height: 1;
  color: #fff7e6;
}

.pw__wordOn {
  display: none;
  color: #ffd23f;
}

.pw.is-on .pw__wordOn {
  display: flex;
}

.pw.is-on .pw__wordOff {
  display: none;
}

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

@keyframes pwPress {
  0%, 6% {
    transform: translateY(0) scale(1);
  }
  11% {
    transform: translateY(4px) scale(0.98);
  }
  16% {
    transform: translateY(0) scale(1);
  }
  57% {
    transform: translateY(0) scale(1);
  }
  62% {
    transform: translateY(4px) scale(0.98);
  }
  68%, 100% {
    transform: translateY(0) scale(1);
  }
}
.pw.is-demo .pw__shade {
  animation-name: pwShade;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes pwShade {
  0% {
    opacity: 0.3;
  }
  7% {
    opacity: 0.8;
  }
  16% {
    opacity: 0.3;
  }
  57% {
    opacity: 0.8;
  }
  68% {
    opacity: 0.3;
  }
  100% {
    opacity: 0.3;
  }
}
.pw.is-demo .pw__led {
  animation-name: pwLed;
  animation-duration: 2s;
  animation-timing-function: ease;
  animation-iteration-count: infinite;
}

@keyframes pwLed {
  0%, 16% {
    box-shadow: inset 0 0 0 3px rgba(255, 210, 63, 0.14);
  }
  28%, 58% {
    box-shadow: inset 0 0 0 3px #ffd23f, 0 0 16px rgba(255, 210, 63, 0.6), 0 0 34px rgba(255, 210, 63, 0.28);
  }
  63%, 100% {
    box-shadow: inset 0 0 0 3px rgba(255, 210, 63, 0.14);
  }
}
.pw.is-demo .pw__mark {
  animation-name: pwMark;
  animation-duration: 2s;
  animation-timing-function: ease;
  animation-iteration-count: infinite;
}

@keyframes pwMark {
  0%, 16% {
    color: #9a93a6;
  }
  28%, 58% {
    color: #ffd23f;
  }
  63%, 100% {
    color: #9a93a6;
  }
}
.pw.is-demo .pw__wordOn {
  display: flex;
  opacity: 0;
}

.pw.is-demo .pw__wordOff {
  opacity: 1;
}

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

@keyframes pwWordOn {
  0%, 18% {
    opacity: 0;
  }
  24% {
    opacity: 1;
  }
  60% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}
.pw.is-demo .pw__wordOff {
  animation-name: pwWordOff;
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
}

@keyframes pwWordOff {
  0%, 18% {
    opacity: 1;
  }
  24% {
    opacity: 0;
  }
  60% {
    opacity: 1;
  }
  100% {
    opacity: 1;
  }
}
@media (max-width: 340px) {
  .pw__col {
    gap: 8px;
  }
  .pw__assembly {
    width: 118px;
    height: 118px;
  }
  .pw__groove {
    inset: 10px;
  }
  .pw__cap {
    inset: 24px;
  }
  .pw__led {
    inset: 18px;
  }
  .pw__shade {
    inset: 20px;
  }
  .pw__mark {
    width: 26px;
    height: 26px;
  }
  .pw__state {
    width: 48px;
    height: 14px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .pw .pw__cap {
    transition: none !important;
  }
  .pw .pw__shade {
    transition: none !important;
  }
  .pw.is-demo .pw__cap {
    animation: none !important;
    transform: translateY(0) scale(1) !important;
  }
  .pw.is-demo .pw__shade {
    animation: none !important;
    opacity: 0.3 !important;
  }
  .pw.is-demo .pw__led {
    animation: none !important;
  }
  .pw.is-demo .pw__mark {
    animation: none !important;
  }
  .pw.is-demo .pw__wordOn {
    animation: none !important;
    opacity: 0 !important;
  }
  .pw.is-demo .pw__wordOff {
    animation: none !important;
    opacity: 1 !important;
  }
}

var pwRoot = document.getElementById('pw');
var pwCap = document.getElementById('pwCap');

function pwSet(on) {
  pwCap.setAttribute('aria-checked', on ? 'true' : 'false');
  pwRoot.classList.toggle('is-on', on);
}
pwCap.addEventListener('pointerdown', function () { pwRoot.classList.remove('is-demo'); });
pwCap.addEventListener('click', function () {
  pwRoot.classList.remove('is-demo');
  pwSet(pwCap.getAttribute('aria-checked') !== 'true');
});

// PowerLedButton — vanilla 판(run/076/demo/01-real-power-led-button/index.html) 의 React 포트.
// 누르면 캡이 안으로 들어가고, 놓으면 캡이 먼저 돌아오고 LED 링은 그 뒤에 서서히 켜진다(비대칭 타이밍).
// 값·키프레임은 vanilla 와 같다(다시 타이핑하지 않는다). 누르면 미리보기 루프를 뗀다.
import { useState } from "react";
import styles from "./PowerLedButton.module.scss";

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

type Vars = { [k: string]: any };

const ARIA_LABEL = "전원";
const STATE_ON = "켜짐";
const STATE_OFF = "꺼짐";

export default function PowerLedButton({
  duration = 220,
  easing = "cubic-bezier(.2, .8, .2, 1)", // = $ease-spring
  color = "#ffd23f",
}: PowerLedButtonProps) {
  const [on, setOn] = useState(false);
  const [demo, setDemo] = useState(true);
  const vars: Vars = {
    "--duration": `${duration}ms`,
    "--easing": easing,
    "--color": color,
  };
  const cls = [styles.root, demo ? styles.isDemo : "", on ? styles.isOn : ""].filter(Boolean).join(" ");

  function wake() {
    setDemo(false);
  }
  function toggle() {
    setDemo(false);
    setOn((prev) => !prev);
  }

  return (
    <main className={styles.stage}>
      <div className={cls} style={vars}>
        <div className={styles.col}>
          <div className={styles.assembly}>
            <span className={styles.bezel} aria-hidden="true"></span>
            <span className={styles.groove} aria-hidden="true"></span>
            <button
              className={styles.cap}
              type="button"
              role="switch"
              aria-checked={on}
              aria-label={ARIA_LABEL}
              onPointerDown={wake}
              onClick={toggle}
            >
              <svg className={styles.mark} viewBox="0 0 24 24" aria-hidden="true" focusable="false">
                <path d="M12 3v6" fill="none" stroke="currentColor" stroke-width="2.3" stroke-linecap="round"></path>
                <path d="M18.4 6.6a7.4 7.4 0 1 1-12.8 0" fill="none" stroke="currentColor" stroke-width="2.3" stroke-linecap="round"></path>
              </svg>
            </button>
            <span className={styles.led} aria-hidden="true"></span>
            <span className={styles.shade} aria-hidden="true"></span>
          </div>
          <p className={styles.state} role="status">
            <span className={styles.wordOn}>{STATE_ON}</span>
            <span className={styles.wordOff}>{STATE_OFF}</span>
          </p>
        </div>
      </div>
    </main>
  );
}