03여러 입력 필드가 한 번에 맞춰 열리는 동기화 토글

<main class="stage">
<div class="pfs is-demo" id="pfsRoot">
  <form class="pfs__form" id="pfsForm" novalidate>
    <label class="pfs__field">
      <span class="pfs__labelText">비밀번호</span>
      <span class="pfs__inputWrap">
        <input class="pfs__input" id="pfsInputA" type="password" autocomplete="new-password" spellcheck="false" value="">
        <button class="pfs__toggle" id="pfsToggleA" type="button" aria-pressed="false" aria-label="비밀번호 표시">
          <svg class="pfs__eye" viewBox="0 0 24 24" width="20" height="20" aria-hidden="true">
            <path class="pfs__lidTop" id="pfsLidTopA" d="M2,12 Q12,4 22,12" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
            <path class="pfs__lidBottom" id="pfsLidBottomA" d="M2,12 Q12,20 22,12" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
            <circle class="pfs__pupil" id="pfsPupilA" cx="12" cy="12" r="3.2" fill="currentColor"/>
          </svg>
        </button>
      </span>
    </label>
    <label class="pfs__field">
      <span class="pfs__labelText">비밀번호 확인</span>
      <span class="pfs__inputWrap">
        <input class="pfs__input" id="pfsInputB" type="password" autocomplete="new-password" spellcheck="false" value="">
        <button class="pfs__toggle" id="pfsToggleB" type="button" aria-pressed="false" aria-label="비밀번호 표시">
          <svg class="pfs__eye" viewBox="0 0 24 24" width="20" height="20" aria-hidden="true">
            <path class="pfs__lidTop" id="pfsLidTopB" d="M2,12 Q12,4 22,12" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
            <path class="pfs__lidBottom" id="pfsLidBottomB" d="M2,12 Q12,20 22,12" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
            <circle class="pfs__pupil" id="pfsPupilB" cx="12" cy="12" r="3.2" fill="currentColor"/>
          </svg>
        </button>
      </span>
    </label>
    <p class="pfs__hint" id="pfsHint">두 칸은 하나의 상태를 공유합니다</p>
  </form>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-orange);

// 계산 겹: 두 필드가 각각 눈 아이콘을 갖지만 실제로 갱신하는 값은 eyeProgress 하나뿐 —
// 어느 버튼을 눌러도 setRevealed() 가 paintEyes() 를 한 번 불러 두 SVG path d 를 같은 프레임에 다시 그린다.
.pfs {
  position: relative;
  width: min(92vw, calc(160vh - 12.8vw));
  aspect-ratio: 480 / 300;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pfs__form {
  width: 100%;
  max-width: 320px;
  box-sizing: border-box;
  display: grid;
  gap: $sp-3;
}

.pfs__field {
  display: grid;
  gap: $sp-2;
}

.pfs__labelText {
  color: rgba($subject-ink, .82);
  font-weight: 600;
  font-size: 13px;
  line-height: 1.3;
}

.pfs__inputWrap {
  position: relative;
  display: flex;
  align-items: center;
}

.pfs__input {
  width: 100%;
  box-sizing: border-box;
  padding: $sp-3 $sp-10 $sp-3 $sp-4;
  border-radius: $r-control;
  border: 0;
  background: rgba($subject-ink, .08);
  color: $subject-ink;
  caret-color: $subject-ink;
  font-weight: 500;
  font-size: 16px;
  line-height: 1.3;
  letter-spacing: .06em;

  &:focus { outline: 2px solid $subject-blue; outline-offset: 2px; }
}

.pfs__toggle {
  position: absolute;
  right: $sp-2;
  top: 50%;
  transform: translateY(-50%);
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: $r-pill;
  background: transparent;
  color: rgba($subject-ink, .78);
  cursor: pointer;

  &:hover { background: rgba($subject-ink, .1); }
  &:focus-visible { outline: 2px solid $subject-blue; outline-offset: 2px; }
}

.pfs__eye { display: block; }

.pfs__hint {
  margin: 0;
  color: rgba($subject-ink, .62);
  font-weight: 500;
  font-size: 11px;
  line-height: 1.4;
  text-align: center;
}

// 배경 톤: 두 필드가 공유하는 revealed 신호 하나를 카드 톤으로 넓힌다(기법 그대로, 계산 겹 추가 없음).
.pfs::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: rgba(91, 140, 248, 0);
  transition: background-color .24s ease;
}
.pfs--revealed::before {
  background: rgba(91, 140, 248, .14);
}

@media (max-width: 340px) {
  .pfs__form { max-width: 260px; }
  .pfs__input { font-size: 14px; padding-right: $sp-8; }
}

@media (prefers-reduced-motion: reduce) {
  .pfs__lidTop,
  .pfs__lidBottom,
  .pfs__pupil {
    transition: none;
  }
  .pfs::before { transition: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.pfs {
  position: relative;
  width: min(92vw, 160vh - 12.8vw);
  aspect-ratio: 480/300;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pfs__form {
  width: 100%;
  max-width: 320px;
  box-sizing: border-box;
  display: grid;
  gap: 12px;
}

.pfs__field {
  display: grid;
  gap: 8px;
}

.pfs__labelText {
  color: rgba(23, 20, 26, 0.82);
  font-weight: 600;
  font-size: 13px;
  line-height: 1.3;
}

.pfs__inputWrap {
  position: relative;
  display: flex;
  align-items: center;
}

.pfs__input {
  width: 100%;
  box-sizing: border-box;
  padding: 12px 40px 12px 16px;
  border-radius: 12px;
  border: 0;
  background: rgba(23, 20, 26, 0.08);
  color: #17141a;
  caret-color: #17141a;
  font-weight: 500;
  font-size: 16px;
  line-height: 1.3;
  letter-spacing: 0.06em;
}
.pfs__input:focus {
  outline: 2px solid #2f6df6;
  outline-offset: 2px;
}

.pfs__toggle {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: rgba(23, 20, 26, 0.78);
  cursor: pointer;
}
.pfs__toggle:hover {
  background: rgba(23, 20, 26, 0.1);
}
.pfs__toggle:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: 2px;
}

.pfs__eye {
  display: block;
}

.pfs__hint {
  margin: 0;
  color: rgba(23, 20, 26, 0.62);
  font-weight: 500;
  font-size: 11px;
  line-height: 1.4;
  text-align: center;
}

.pfs::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: rgba(91, 140, 248, 0);
  transition: background-color 0.24s ease;
}

.pfs--revealed::before {
  background: rgba(91, 140, 248, 0.14);
}

@media (max-width: 340px) {
  .pfs__form {
    max-width: 260px;
  }
  .pfs__input {
    font-size: 14px;
    padding-right: 32px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .pfs__lidTop,
  .pfs__lidBottom,
  .pfs__pupil {
    transition: none;
  }
  .pfs::before {
    transition: none;
  }
}

(function () {
  // 기법: 두 필드가 각자 토글 버튼을 갖지만 실제로 바꾸는 값은 단 하나(shared revealed)뿐이다.
  // 어느 버튼을 눌러도 setRevealed() 하나가 두 input·두 눈 아이콘을 동시에 갱신하고, 눈 모프는
  // 공유 eyeProgress 값 하나로 두 SVG 를 같은 프레임에 다시 그린다(paintEyes).
  var root = document.getElementById('pfsRoot');
  var form = document.getElementById('pfsForm');
  var inputA = document.getElementById('pfsInputA');
  var inputB = document.getElementById('pfsInputB');
  var toggleA = document.getElementById('pfsToggleA');
  var toggleB = document.getElementById('pfsToggleB');
  var lidTopA = document.getElementById('pfsLidTopA');
  var lidBottomA = document.getElementById('pfsLidBottomA');
  var pupilA = document.getElementById('pfsPupilA');
  var lidTopB = document.getElementById('pfsLidTopB');
  var lidBottomB = document.getElementById('pfsLidBottomB');
  var pupilB = document.getElementById('pfsPupilB');

  var SYNC_EYE_MORPH_MS = 260;
  var LABEL_SHOW = '비밀번호 표시';
  var LABEL_HIDE = '비밀번호 숨기기';

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }
  var pwRand = seedRand(426031);
  var POOL_ALL = 'ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789!@#$%*?-';
  function makeFakePassword() {
    var len = 8 + Math.floor(pwRand() * 5);
    var out = '';
    for (var i = 0; i < len; i += 1) out += POOL_ALL.charAt(Math.floor(pwRand() * POOL_ALL.length));
    return out;
  }
  var FAKE_PW = makeFakePassword();
  inputA.value = FAKE_PW;
  inputB.value = FAKE_PW;

  function easeOutCubic(t) { return 1 - Math.pow(1 - t, 3); }

  function paintEyes(progress) {
    var eased = easeOutCubic(progress);
    var topY = 12 - 8 * eased;
    var botY = 12 + 8 * eased;
    var d1 = 'M2,12 Q12,' + topY + ' 22,12';
    var d2 = 'M2,12 Q12,' + botY + ' 22,12';
    lidTopA.setAttribute('d', d1);
    lidBottomA.setAttribute('d', d2);
    pupilA.style.opacity = String(eased);
    lidTopB.setAttribute('d', d1);
    lidBottomB.setAttribute('d', d2);
    pupilB.style.opacity = String(eased);
  }

  var eyeProgress = 0;
  var eyeRaf = null;
  var animT0 = null, animStart = 0, animTarget = 0;
  paintEyes(eyeProgress);

  function animateEyeStep(ts) {
    if (animT0 === null) animT0 = ts;
    var elapsed = ts - animT0;
    var p = Math.min(1, elapsed / SYNC_EYE_MORPH_MS);
    eyeProgress = animStart + (animTarget - animStart) * p;
    paintEyes(eyeProgress);
    if (p < 1) { eyeRaf = requestAnimationFrame(animateEyeStep); }
    else { eyeRaf = null; eyeProgress = animTarget; paintEyes(eyeProgress); }
  }
  function animateEyeTo(target) {
    if (eyeRaf) { cancelAnimationFrame(eyeRaf); eyeRaf = null; }
    if (reduce) { eyeProgress = target; paintEyes(eyeProgress); return; }
    animStart = eyeProgress;
    animTarget = target;
    animT0 = null;
    eyeRaf = requestAnimationFrame(animateEyeStep);
  }

  var revealed = false;
  function setRevealed(next) {
    revealed = next;
    var type = revealed ? 'text' : 'password';
    inputA.type = type;
    inputB.type = type;
    root.classList.toggle('pfs--revealed', revealed);
    var label = revealed ? LABEL_HIDE : LABEL_SHOW;
    toggleA.setAttribute('aria-pressed', String(revealed));
    toggleA.setAttribute('aria-label', label);
    toggleB.setAttribute('aria-pressed', String(revealed));
    toggleB.setAttribute('aria-label', label);
    animateEyeTo(revealed ? 1 : 0);
  }

  function onToggle() {
    root.classList.remove('is-demo');
    setRevealed(!revealed);
  }
  toggleA.addEventListener('click', onToggle);
  toggleB.addEventListener('click', onToggle);

  form.addEventListener('submit', function (e) { e.preventDefault(); });

  if (reduce) { root.classList.remove('is-demo'); }

  function demoLoop() {
    if (reduce) return;
    setRevealed(true);
    setTimeout(function () { setRevealed(false); }, 900);
    setTimeout(demoLoop, 2000);
  }
  if (!reduce) { setTimeout(demoLoop, 220); }
})();

import { useEffect, useRef } from "react";
import styles from "./PasswordRevealMultiFieldSyncToggle.module.scss";

type Box<T> = { current: T };

const SYNC_EYE_MORPH_MS = 260;
const LABEL_SHOW = "비밀번호 표시";
const LABEL_HIDE = "비밀번호 숨기기";

export default function PasswordRevealMultiFieldSyncToggle() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;
  const formRef = useRef(null) as unknown as Box<HTMLFormElement | null>;
  const inputARef = useRef(null) as unknown as Box<HTMLInputElement | null>;
  const inputBRef = useRef(null) as unknown as Box<HTMLInputElement | null>;
  const toggleARef = useRef(null) as unknown as Box<HTMLButtonElement | null>;
  const toggleBRef = useRef(null) as unknown as Box<HTMLButtonElement | null>;
  const lidTopARef = useRef(null) as unknown as Box<SVGPathElement | null>;
  const lidBottomARef = useRef(null) as unknown as Box<SVGPathElement | null>;
  const pupilARef = useRef(null) as unknown as Box<SVGCircleElement | null>;
  const lidTopBRef = useRef(null) as unknown as Box<SVGPathElement | null>;
  const lidBottomBRef = useRef(null) as unknown as Box<SVGPathElement | null>;
  const pupilBRef = useRef(null) as unknown as Box<SVGCircleElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    const form = formRef.current;
    const inputA = inputARef.current;
    const inputB = inputBRef.current;
    const toggleA = toggleARef.current;
    const toggleB = toggleBRef.current;
    const lidTopA = lidTopARef.current;
    const lidBottomA = lidBottomARef.current;
    const pupilA = pupilARef.current;
    const lidTopB = lidTopBRef.current;
    const lidBottomB = lidBottomBRef.current;
    const pupilB = pupilBRef.current;
    if (!root || !form || !inputA || !inputB || !toggleA || !toggleB || !lidTopA || !lidBottomA || !pupilA || !lidTopB || !lidBottomB || !pupilB) return;

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
    }
    const pwRand = seedRand(426032);
    const POOL_ALL = "ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnpqrstuvwxyz23456789!@#$%*?-";
    function makeFakePassword() {
      const len = 8 + Math.floor(pwRand() * 5);
      let out = "";
      for (let i = 0; i < len; i += 1) out += POOL_ALL.charAt(Math.floor(pwRand() * POOL_ALL.length));
      return out;
    }
    const FAKE_PW = makeFakePassword();
    inputA.value = FAKE_PW;
    inputB.value = FAKE_PW;

    function easeOutCubic(t: number) { return 1 - Math.pow(1 - t, 3); }

    function paintEyes(progress: number) {
      const eased = easeOutCubic(progress);
      const topY = 12 - 8 * eased;
      const botY = 12 + 8 * eased;
      const d1 = "M2,12 Q12," + topY + " 22,12";
      const d2 = "M2,12 Q12," + botY + " 22,12";
      lidTopA!.setAttribute("d", d1);
      lidBottomA!.setAttribute("d", d2);
      pupilA!.style.opacity = String(eased);
      lidTopB!.setAttribute("d", d1);
      lidBottomB!.setAttribute("d", d2);
      pupilB!.style.opacity = String(eased);
    }

    let eyeProgress = 0;
    let eyeRaf = 0;
    let animT0: number | null = null;
    let animStart = 0;
    let animTarget = 0;
    paintEyes(eyeProgress);

    function animateEyeStep(ts: number) {
      if (animT0 === null) animT0 = ts;
      const elapsed = ts - animT0;
      const p = Math.min(1, elapsed / SYNC_EYE_MORPH_MS);
      eyeProgress = animStart + (animTarget - animStart) * p;
      paintEyes(eyeProgress);
      if (p < 1) { eyeRaf = requestAnimationFrame(animateEyeStep); }
      else { eyeRaf = 0; eyeProgress = animTarget; paintEyes(eyeProgress); }
    }
    function animateEyeTo(target: number) {
      if (eyeRaf) { cancelAnimationFrame(eyeRaf); eyeRaf = 0; }
      if (reduce) { eyeProgress = target; paintEyes(eyeProgress); return; }
      animStart = eyeProgress;
      animTarget = target;
      animT0 = null;
      eyeRaf = requestAnimationFrame(animateEyeStep);
    }

    let revealed = false;
    function setRevealed(next: boolean) {
      revealed = next;
      const type = revealed ? "text" : "password";
      inputA!.type = type;
      inputB!.type = type;
      root!.classList.toggle(styles["is-revealed"], revealed);
      const label = revealed ? LABEL_HIDE : LABEL_SHOW;
      toggleA!.setAttribute("aria-pressed", String(revealed));
      toggleA!.setAttribute("aria-label", label);
      toggleB!.setAttribute("aria-pressed", String(revealed));
      toggleB!.setAttribute("aria-label", label);
      animateEyeTo(revealed ? 1 : 0);
    }

    function onToggle() {
      root!.classList.remove(styles["is-demo"]);
      setRevealed(!revealed);
    }
    toggleA.addEventListener("click", onToggle);
    toggleB.addEventListener("click", onToggle);

    function onSubmit(e: Event) { e.preventDefault(); }
    form.addEventListener("submit", onSubmit);

    if (reduce) { root.classList.remove(styles["is-demo"]); }

    let loopTimer = 0;
    let closeTimer = 0;
    function demoLoop() {
      if (reduce) return;
      setRevealed(true);
      closeTimer = window.setTimeout(function () { setRevealed(false); }, 900);
      loopTimer = window.setTimeout(demoLoop, 2000);
    }
    let startTimer = 0;
    if (!reduce) { startTimer = window.setTimeout(demoLoop, 220); }

    return () => {
      toggleA.removeEventListener("click", onToggle);
      toggleB.removeEventListener("click", onToggle);
      form.removeEventListener("submit", onSubmit);
      if (eyeRaf) cancelAnimationFrame(eyeRaf);
      window.clearTimeout(startTimer);
      window.clearTimeout(loopTimer);
      window.clearTimeout(closeTimer);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div ref={rootRef} className={`${styles.pfs} ${styles["is-demo"]}`}>
        <form ref={formRef} className={styles.form} noValidate>
          <label className={styles.field}>
            <span className={styles.labelText}>비밀번호</span>
            <span className={styles.inputWrap}>
              <input
                ref={inputARef}
                className={styles.input}
                type="password"
                autoComplete="new-password"
                spellCheck={false}
                defaultValue=""
              />
              <button ref={toggleARef} className={styles.toggle} type="button" aria-pressed="false" aria-label="비밀번호 표시">
                <svg className={styles.eye} viewBox="0 0 24 24" width={20} height={20} aria-hidden="true">
                  <path ref={lidTopARef} d="M2,12 Q12,4 22,12" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" />
                  <path ref={lidBottomARef} d="M2,12 Q12,20 22,12" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" />
                  <circle ref={pupilARef} cx={12} cy={12} r={3.2} fill="currentColor" />
                </svg>
              </button>
            </span>
          </label>
          <label className={styles.field}>
            <span className={styles.labelText}>비밀번호 확인</span>
            <span className={styles.inputWrap}>
              <input
                ref={inputBRef}
                className={styles.input}
                type="password"
                autoComplete="new-password"
                spellCheck={false}
                defaultValue=""
              />
              <button ref={toggleBRef} className={styles.toggle} type="button" aria-pressed="false" aria-label="비밀번호 표시">
                <svg className={styles.eye} viewBox="0 0 24 24" width={20} height={20} aria-hidden="true">
                  <path ref={lidTopBRef} d="M2,12 Q12,4 22,12" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" />
                  <path ref={lidBottomBRef} d="M2,12 Q12,20 22,12" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" />
                  <circle ref={pupilBRef} cx={12} cy={12} r={3.2} fill="currentColor" />
                </svg>
              </button>
            </span>
          </label>
          <p className={styles.hint}>두 칸은 하나의 상태를 공유합니다</p>
        </form>
      </div>
    </main>
  );
}