04Lightbox Navigated by Swiping Next and Previous

<main class="stage">
<div class="scene is-demo" id="scene">
  <ul class="grid" id="grid">
    <li><button class="thumb" id="thumb0" type="button" aria-haspopup="dialog"><span class="thumbImg thumbImg--a"></span></button></li>
    <li><button class="thumb" id="thumb1" type="button" aria-haspopup="dialog"><span class="thumbImg thumbImg--b"></span></button></li>
    <li><button class="thumb" id="thumb2" type="button" aria-haspopup="dialog"><span class="thumbImg thumbImg--c"></span></button></li>
  </ul>
  <div class="backdrop" id="backdrop"></div>
  <div class="lightbox" id="lightbox" role="dialog" aria-modal="true" aria-hidden="true" aria-label="Browse photos">
    <div class="viewport" id="viewport">
      <div class="track" id="track">
        <span class="fullImg fullImg--a"></span>
        <span class="fullImg fullImg--b"></span>
        <span class="fullImg fullImg--c"></span>
      </div>
    </div>
    <button class="navBtn navBtn--prev" id="prevBtn" type="button" aria-label="Previous photo"><svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="M160 48v160l-80-80Z" opacity=".2"/><path d="M163.06 40.61a8 8 0 0 0-8.72 1.73l-80 80a8 8 0 0 0 0 11.32l80 80A8 8 0 0 0 168 208V48a8 8 0 0 0-4.94-7.39M152 188.69L91.31 128L152 67.31Z"/></g></svg></button>
    <button class="navBtn navBtn--next" id="nextBtn" type="button" aria-label="Next photo"><svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true"><g fill="currentColor"><path d="m176 128l-80 80V48Z" opacity=".2"/><path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z"/></g></svg></button>
    <p class="counter" id="counter" aria-live="polite">1 / 3</p>
    <button class="closeBtn" id="closeBtn" type="button">Close</button>
  </div>
</div>
</main>

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

// 변수 3개
$duration: $dur-base;
$easing: $ease-out;
$color: $subject-blue-light;

// 계산 겹: index.html 의 pointermove 가 매 이동마다 속도(px/ms)를 계산하고, pointerup 에서
// 드래그 거리 비율 또는 그 속도가 문턱을 넘는지로 다음/이전 커밋 여부를 판정한다.
@include stage($stage-paper);

.scene {
  position: relative;
  width: 320px;
  height: 180px;
  border-radius: $r-card;
  overflow: hidden;
  box-shadow: $shadow-raised;
  background: linear-gradient(160deg, #f3f1ea, $stage-paper 70%);
}

.grid {
  position: absolute;
  inset: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: $sp-4;
}

.thumb {
  appearance: none;
  border: none;
  background: none;
  padding: 0;
  cursor: pointer;

  &:focus-visible .thumbImg { outline: 2px solid $color; outline-offset: 2px; }
}

.thumbImg {
  display: block;
  width: 58px;
  height: 58px;
  border-radius: $r-sm;
  box-shadow: $shadow-press;

  &--a { background: linear-gradient(135deg, $subject-blue, $subject-lilac); }
  &--b { background: linear-gradient(135deg, $subject-mint, $subject-sky); }
  &--c { background: linear-gradient(135deg, $subject-pink, $subject-lilac); }
}

.backdrop {
  position: absolute;
  inset: 0;
  background: $subject-ink;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.lightbox {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  visibility: hidden;
}

.viewport {
  position: relative;
  width: 220px;
  height: 130px;
  border-radius: $r-card;
  overflow: hidden;
  touch-action: pan-y;
}

.track {
  display: flex;
  width: 660px;
  height: 100%;
}

.fullImg {
  display: block;
  width: 220px;
  height: 100%;
  flex: 0 0 auto;

  &--a { background: linear-gradient(135deg, $subject-blue, $subject-lilac); }
  &--b { background: linear-gradient(135deg, $subject-mint, $subject-sky); }
  &--c { background: linear-gradient(135deg, $subject-pink, $subject-lilac); }
}

.navBtn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  appearance: none;
  border: none;
  width: 28px;
  height: 28px;
  border-radius: $r-pill;
  display: grid;
  place-items: center;
  background: rgba(#000, .38);
  color: $subject-cream;
  font-size: 16px;
  cursor: pointer;

  &--prev { left: $sp-2; }
  &--next { right: $sp-2; }
  &:focus-visible { outline: 2px solid $color; outline-offset: 2px; }
}

.counter {
  position: absolute;
  bottom: $sp-2;
  left: 50%;
  transform: translateX(-50%);
  margin: 0;
  font-size: 10px;
  font-weight: 700;
  color: $subject-cream;
  background: rgba(#000, .4);
  padding: $sp-1 $sp-2;
  border-radius: $r-pill;
}

.closeBtn {
  position: absolute;
  top: $sp-2;
  right: $sp-2;
  appearance: none;
  border: none;
  border-radius: $r-pill;
  padding: $sp-1 $sp-3;
  font-size: 11px;
  font-weight: 600;
  color: $subject-ink;
  background: rgba($subject-cream, .92);
  cursor: pointer;

  &:focus-visible { outline: 2px solid $color; outline-offset: 2px; }
}

@media (max-width: 340px) {
  .scene { width: 220px; height: 124px; }
  .viewport { width: 160px; height: 96px; }
  .track { width: 480px; }
  .fullImg { width: 160px; }
  .navBtn { width: 24px; height: 24px; font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  // 실사용 경로 적용 — 스와이프 커밋·백드롭 트윈은 index.html 의 animate() 가 reduce 시 즉시 최종 상태로 처리한다.
  .closeBtn, .navBtn, .thumb { transition: none; }
}

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

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

.scene {
  position: relative;
  width: 320px;
  height: 180px;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  background: linear-gradient(160deg, #f3f1ea, #ffffff 70%);
}

.grid {
  position: absolute;
  inset: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.thumb {
  appearance: none;
  border: none;
  background: none;
  padding: 0;
  cursor: pointer;
}
.thumb:focus-visible .thumbImg {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.thumbImg {
  display: block;
  width: 58px;
  height: 58px;
  border-radius: 8px;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}
.thumbImg--a {
  background: linear-gradient(135deg, #2f6df6, #b9a0ff);
}
.thumbImg--b {
  background: linear-gradient(135deg, #4cd4a6, #6ec8ff);
}
.thumbImg--c {
  background: linear-gradient(135deg, #ff9ebb, #b9a0ff);
}

.backdrop {
  position: absolute;
  inset: 0;
  background: #17141a;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.lightbox {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  visibility: hidden;
}

.viewport {
  position: relative;
  width: 220px;
  height: 130px;
  border-radius: 16px;
  overflow: hidden;
  touch-action: pan-y;
}

.track {
  display: flex;
  width: 660px;
  height: 100%;
}

.fullImg {
  display: block;
  width: 220px;
  height: 100%;
  flex: 0 0 auto;
}
.fullImg--a {
  background: linear-gradient(135deg, #2f6df6, #b9a0ff);
}
.fullImg--b {
  background: linear-gradient(135deg, #4cd4a6, #6ec8ff);
}
.fullImg--c {
  background: linear-gradient(135deg, #ff9ebb, #b9a0ff);
}

.navBtn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  appearance: none;
  border: none;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: rgba(0, 0, 0, 0.38);
  color: #fff7e6;
  font-size: 16px;
  cursor: pointer;
}
.navBtn--prev {
  left: 8px;
}
.navBtn--next {
  right: 8px;
}
.navBtn:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.counter {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  margin: 0;
  font-size: 10px;
  font-weight: 700;
  color: #fff7e6;
  background: rgba(0, 0, 0, 0.4);
  padding: 4px 8px;
  border-radius: 999px;
}

.closeBtn {
  position: absolute;
  top: 8px;
  right: 8px;
  appearance: none;
  border: none;
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 11px;
  font-weight: 600;
  color: #17141a;
  background: rgba(255, 247, 230, 0.92);
  cursor: pointer;
}
.closeBtn:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

@media (max-width: 340px) {
  .scene {
    width: 220px;
    height: 124px;
  }
  .viewport {
    width: 160px;
    height: 96px;
  }
  .track {
    width: 480px;
  }
  .fullImg {
    width: 160px;
  }
  .navBtn {
    width: 24px;
    height: 24px;
    font-size: 13px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .closeBtn, .navBtn, .thumb {
    transition: none;
  }
}

(function () {
  var SWIPE_COMMIT_RATIO = 0.25; // 드래그 거리 / 뷰포트 폭 이 이 비율을 넘으면 커밋
  var SWIPE_VELOCITY_PX_MS = 0.5; // 놓는 순간 속도(px/ms) 가 이 값을 넘어도 커밋
  var SNAP_MS = 320;
  var LOOP_MS = 2000;

  var scene = document.getElementById('scene');
  var backdrop = document.getElementById('backdrop');
  var lightbox = document.getElementById('lightbox');
  var viewport = document.getElementById('viewport');
  var track = document.getElementById('track');
  var prevBtn = document.getElementById('prevBtn');
  var nextBtn = document.getElementById('nextBtn');
  var counter = document.getElementById('counter');
  var closeBtn = document.getElementById('closeBtn');
  var thumbs = [].slice.call(document.querySelectorAll('.thumb'));
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var COUNT = 3;
  var idx = 0;
  var open = false;
  var dragging = false;
  var dragStartX = 0;
  var dragBaseX = 0;
  var lastMoveX = 0;
  var lastMoveT = 0;
  var velocity = 0;
  var timers = [];

  function clamp(v, lo, hi) { return Math.min(hi, Math.max(lo, v)); }
  function easeOutCubic(t) { return 1 - Math.pow(1 - t, 3); }
  function viewportW() { return viewport.getBoundingClientRect().width; }

  function animate(duration, onFrame, onDone) {
    if (reduce) { onFrame(1); if (onDone) onDone(); return; }
    var start = performance.now();
    function frame(now) {
      var p = clamp((now - start) / duration, 0, 1);
      onFrame(easeOutCubic(p));
      if (p < 1) requestAnimationFrame(frame);
      else if (onDone) onDone();
    }
    requestAnimationFrame(frame);
  }

  function setTrackX(px) { track.style.transform = 'translateX(' + px.toFixed(2) + 'px)'; }
  function baseXFor(i) { return -i * viewportW(); }

  function goTo(nextIdx, onDone) {
    nextIdx = clamp(nextIdx, 0, COUNT - 1);
    var fromX = baseXFor(idx);
    var toX = baseXFor(nextIdx);
    animate(SNAP_MS, function (e) {
      setTrackX(fromX + (toX - fromX) * e);
    }, function () {
      idx = nextIdx;
      counter.textContent = (idx + 1) + ' / ' + COUNT;
      if (onDone) onDone();
    });
  }

  function openFrom(startIdx) {
    if (open) return;
    open = true;
    idx = startIdx;
    setTrackX(baseXFor(idx));
    counter.textContent = (idx + 1) + ' / ' + COUNT;
    lightbox.style.visibility = 'visible';
    lightbox.setAttribute('aria-hidden', 'false');
    backdrop.style.visibility = 'visible';
    backdrop.style.opacity = '0';
    animate(260, function (e) { backdrop.style.opacity = (e * 0.78).toFixed(3); }, function () {
      closeBtn.focus({ preventScroll: true });
    });
  }

  function closeLightbox() {
    if (!open) return;
    animate(240, function (e) { backdrop.style.opacity = (0.78 * (1 - e)).toFixed(3); }, function () {
      lightbox.style.visibility = 'hidden';
      lightbox.setAttribute('aria-hidden', 'true');
      backdrop.style.visibility = 'hidden';
      open = false;
      thumbs[idx].focus({ preventScroll: true });
    });
  }

  function human() {
    if (scene.classList.contains('is-demo')) {
      scene.classList.remove('is-demo');
      timers.forEach(function (id) { clearTimeout(id); clearInterval(id); });
      timers = [];
    }
  }

  thumbs.forEach(function (t, i) {
    t.addEventListener('click', function () { human(); openFrom(i); });
  });
  closeBtn.addEventListener('click', function () { human(); closeLightbox(); });
  backdrop.addEventListener('click', function () { human(); closeLightbox(); });
  prevBtn.addEventListener('click', function () { human(); goTo(idx - 1); });
  nextBtn.addEventListener('click', function () { human(); goTo(idx + 1); });
  document.addEventListener('keydown', function (e) {
    if (!open) return;
    if (e.key === 'Escape') { human(); closeLightbox(); }
    else if (e.key === 'ArrowLeft') { human(); goTo(idx - 1); }
    else if (e.key === 'ArrowRight') { human(); goTo(idx + 1); }
  });

  viewport.addEventListener('pointerdown', function (e) {
    human();
    dragging = true;
    dragStartX = e.clientX;
    dragBaseX = baseXFor(idx);
    lastMoveX = e.clientX;
    lastMoveT = performance.now();
    velocity = 0;
    viewport.setPointerCapture(e.pointerId);
  });
  viewport.addEventListener('pointermove', function (e) {
    if (!dragging) return;
    var now = performance.now();
    var dt = now - lastMoveT;
    if (dt > 0) velocity = (e.clientX - lastMoveX) / dt;
    lastMoveX = e.clientX;
    lastMoveT = now;
    setTrackX(dragBaseX + (e.clientX - dragStartX));
  });
  function endDrag(e) {
    if (!dragging) return;
    dragging = false;
    var deltaX = e.clientX - dragStartX;
    var w = viewportW();
    var commit = Math.abs(deltaX) > w * SWIPE_COMMIT_RATIO || Math.abs(velocity) > SWIPE_VELOCITY_PX_MS;
    if (commit) {
      goTo(idx + (deltaX < 0 ? 1 : -1));
    } else {
      goTo(idx);
    }
  }
  viewport.addEventListener('pointerup', endDrag);
  viewport.addEventListener('pointercancel', endDrag);

  function cycle() {
    openFrom(0);
    timers.push(setTimeout(function () { goTo(1); }, 420));
    timers.push(setTimeout(function () { goTo(2); }, 1020));
    timers.push(setTimeout(closeLightbox, 1620));
  }

  if (!reduce) {
    cycle();
    timers.push(setInterval(function () {
      if (scene.classList.contains('is-demo')) cycle();
    }, LOOP_MS));
  }
})();

import { useEffect, useRef } from 'react';
import styles from './SwipeNextPrev.module.scss';

const SWIPE_COMMIT_RATIO = 0.25; // 드래그 거리 / 뷰포트 폭 이 이 비율을 넘으면 커밋
const SWIPE_VELOCITY_PX_MS = 0.5; // 놓는 순간 속도(px/ms) 가 이 값을 넘어도 커밋
const SNAP_MS = 320;
const LOOP_MS = 2000;
const COUNT = 3;

export default function SwipeNextPrev() {
  const sceneRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const scene0 = sceneRef.current;
    if (!scene0) return undefined;
    const backdrop0 = scene0.querySelector<HTMLDivElement>('.' + styles.backdrop);
    const lightbox0 = scene0.querySelector<HTMLDivElement>('.' + styles.lightbox);
    const viewport0 = scene0.querySelector<HTMLDivElement>('.' + styles.viewport);
    const track0 = scene0.querySelector<HTMLDivElement>('.' + styles.track);
    const prevBtn0 = scene0.querySelector<HTMLButtonElement>('.' + styles['navBtn--prev']);
    const nextBtn0 = scene0.querySelector<HTMLButtonElement>('.' + styles['navBtn--next']);
    const counter0 = scene0.querySelector<HTMLParagraphElement>('.' + styles.counter);
    const closeBtn0 = scene0.querySelector<HTMLButtonElement>('.' + styles.closeBtn);
    const thumbs = Array.from(scene0.querySelectorAll<HTMLButtonElement>('.' + styles.thumb));
    if (!backdrop0 || !lightbox0 || !viewport0 || !track0 || !prevBtn0 || !nextBtn0 || !counter0 || !closeBtn0 || thumbs.length === 0) return undefined;
    const scene = scene0;
    const backdrop = backdrop0;
    const lightbox = lightbox0;
    const viewport = viewport0;
    const track = track0;
    const prevBtn = prevBtn0;
    const nextBtn = nextBtn0;
    const counter = counter0;
    const closeBtn = closeBtn0;

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

    let idx = 0;
    let open = false;
    let dragging = false;
    let dragStartX = 0;
    let dragBaseX = 0;
    let lastMoveX = 0;
    let lastMoveT = 0;
    let velocity = 0;
    let timers: number[] = [];

    function clamp(v: number, lo: number, hi: number) { return Math.min(hi, Math.max(lo, v)); }
    function easeOutCubic(t: number) { return 1 - Math.pow(1 - t, 3); }
    function viewportW() { return viewport.getBoundingClientRect().width; }

    function animate(duration: number, onFrame: (e: number) => void, onDone?: () => void) {
      if (reduce) { onFrame(1); if (onDone) onDone(); return; }
      const start = performance.now();
      function frame(now: number) {
        const p = clamp((now - start) / duration, 0, 1);
        onFrame(easeOutCubic(p));
        if (p < 1) requestAnimationFrame(frame);
        else if (onDone) onDone();
      }
      requestAnimationFrame(frame);
    }

    function setTrackX(px: number) { track.style.transform = 'translateX(' + px.toFixed(2) + 'px)'; }
    function baseXFor(i: number) { return -i * viewportW(); }

    function goTo(nextIdxRaw: number, onDone?: () => void) {
      const nextIdx = clamp(nextIdxRaw, 0, COUNT - 1);
      const fromX = baseXFor(idx);
      const toX = baseXFor(nextIdx);
      animate(SNAP_MS, (e) => {
        setTrackX(fromX + (toX - fromX) * e);
      }, () => {
        idx = nextIdx;
        counter.textContent = (idx + 1) + ' / ' + COUNT;
        if (onDone) onDone();
      });
    }

    function openFrom(startIdx: number) {
      if (open) return;
      open = true;
      idx = startIdx;
      setTrackX(baseXFor(idx));
      counter.textContent = (idx + 1) + ' / ' + COUNT;
      lightbox.style.visibility = 'visible';
      lightbox.setAttribute('aria-hidden', 'false');
      backdrop.style.visibility = 'visible';
      backdrop.style.opacity = '0';
      animate(260, (e) => { backdrop.style.opacity = (e * 0.78).toFixed(3); }, () => {
        closeBtn.focus({ preventScroll: true });
      });
    }

    function closeLightbox() {
      if (!open) return;
      animate(240, (e) => { backdrop.style.opacity = (0.78 * (1 - e)).toFixed(3); }, () => {
        lightbox.style.visibility = 'hidden';
        lightbox.setAttribute('aria-hidden', 'true');
        backdrop.style.visibility = 'hidden';
        open = false;
        thumbs[idx].focus({ preventScroll: true });
      });
    }

    function human() {
      if (scene.classList.contains(styles['is-demo'])) {
        scene.classList.remove(styles['is-demo']);
        timers.forEach((id) => { window.clearTimeout(id); window.clearInterval(id); });
        timers = [];
      }
    }

    const thumbHandlers = thumbs.map((_, i) => () => { human(); openFrom(i); });
    thumbs.forEach((t, i) => t.addEventListener('click', thumbHandlers[i]));

    function onCloseClick() { human(); closeLightbox(); }
    function onBackdropClick() { human(); closeLightbox(); }
    function onPrevClick() { human(); goTo(idx - 1); }
    function onNextClick() { human(); goTo(idx + 1); }
    function onKeydown(e: KeyboardEvent) {
      if (!open) return;
      if (e.key === 'Escape') { human(); closeLightbox(); }
      else if (e.key === 'ArrowLeft') { human(); goTo(idx - 1); }
      else if (e.key === 'ArrowRight') { human(); goTo(idx + 1); }
    }
    closeBtn.addEventListener('click', onCloseClick);
    backdrop.addEventListener('click', onBackdropClick);
    prevBtn.addEventListener('click', onPrevClick);
    nextBtn.addEventListener('click', onNextClick);
    document.addEventListener('keydown', onKeydown);

    function onPointerDown(e: PointerEvent) {
      human();
      dragging = true;
      dragStartX = e.clientX;
      dragBaseX = baseXFor(idx);
      lastMoveX = e.clientX;
      lastMoveT = performance.now();
      velocity = 0;
      viewport.setPointerCapture(e.pointerId);
    }
    function onPointerMove(e: PointerEvent) {
      if (!dragging) return;
      const now = performance.now();
      const dt = now - lastMoveT;
      if (dt > 0) velocity = (e.clientX - lastMoveX) / dt;
      lastMoveX = e.clientX;
      lastMoveT = now;
      setTrackX(dragBaseX + (e.clientX - dragStartX));
    }
    function endDrag(e: PointerEvent) {
      if (!dragging) return;
      dragging = false;
      const deltaX = e.clientX - dragStartX;
      const w = viewportW();
      const commit = Math.abs(deltaX) > w * SWIPE_COMMIT_RATIO || Math.abs(velocity) > SWIPE_VELOCITY_PX_MS;
      if (commit) goTo(idx + (deltaX < 0 ? 1 : -1));
      else goTo(idx);
    }
    viewport.addEventListener('pointerdown', onPointerDown);
    viewport.addEventListener('pointermove', onPointerMove);
    viewport.addEventListener('pointerup', endDrag);
    viewport.addEventListener('pointercancel', endDrag);

    function cycle() {
      openFrom(0);
      timers.push(window.setTimeout(() => { goTo(1); }, 420));
      timers.push(window.setTimeout(() => { goTo(2); }, 1020));
      timers.push(window.setTimeout(closeLightbox, 1620));
    }

    if (!reduce) {
      cycle();
      timers.push(window.setInterval(() => {
        if (scene.classList.contains(styles['is-demo'])) cycle();
      }, LOOP_MS));
    }

    return () => {
      timers.forEach((id) => { window.clearTimeout(id); window.clearInterval(id); });
      thumbs.forEach((t, i) => t.removeEventListener('click', thumbHandlers[i]));
      closeBtn.removeEventListener('click', onCloseClick);
      backdrop.removeEventListener('click', onBackdropClick);
      prevBtn.removeEventListener('click', onPrevClick);
      nextBtn.removeEventListener('click', onNextClick);
      document.removeEventListener('keydown', onKeydown);
      viewport.removeEventListener('pointerdown', onPointerDown);
      viewport.removeEventListener('pointermove', onPointerMove);
      viewport.removeEventListener('pointerup', endDrag);
      viewport.removeEventListener('pointercancel', endDrag);
    };
  }, []);

  return (
    <div className={`${styles.scene} ${styles['is-demo']}`} ref={sceneRef}>
      <ul className={styles.grid}>
        <li><button className={styles.thumb} type="button" aria-haspopup="dialog"><span className={`${styles.thumbImg} ${styles['thumbImg--a']}`} /></button></li>
        <li><button className={styles.thumb} type="button" aria-haspopup="dialog"><span className={`${styles.thumbImg} ${styles['thumbImg--b']}`} /></button></li>
        <li><button className={styles.thumb} type="button" aria-haspopup="dialog"><span className={`${styles.thumbImg} ${styles['thumbImg--c']}`} /></button></li>
      </ul>
      <div className={styles.backdrop} />
      <div className={styles.lightbox} role="dialog" aria-modal="true" aria-hidden="true" aria-label="사진 넘겨보기">
        <div className={styles.viewport}>
          <div className={styles.track}>
            <span className={`${styles.fullImg} ${styles['fullImg--a']}`} />
            <span className={`${styles.fullImg} ${styles['fullImg--b']}`} />
            <span className={`${styles.fullImg} ${styles['fullImg--c']}`} />
          </div>
        </div>
        <button className={`${styles.navBtn} ${styles['navBtn--prev']}`} type="button" aria-label="이전 사진">
          <svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true">
            <g fill="currentColor">
              <path d="M160 48v160l-80-80Z" opacity=".2" />
              <path d="M163.06 40.61a8 8 0 0 0-8.72 1.73l-80 80a8 8 0 0 0 0 11.32l80 80A8 8 0 0 0 168 208V48a8 8 0 0 0-4.94-7.39M152 188.69L91.31 128L152 67.31Z" />
            </g>
          </svg>
        </button>
        <button className={`${styles.navBtn} ${styles['navBtn--next']}`} type="button" aria-label="다음 사진">
          <svg xmlns="http://www.w3.org/2000/svg" width="1em" height="1em" viewBox="0 0 256 256" aria-hidden="true">
            <g fill="currentColor">
              <path d="m176 128l-80 80V48Z" opacity=".2" />
              <path d="m181.66 122.34l-80-80A8 8 0 0 0 88 48v160a8 8 0 0 0 13.66 5.66l80-80a8 8 0 0 0 0-11.32M104 188.69V67.31L164.69 128Z" />
            </g>
          </svg>
        </button>
        <p className={styles.counter} aria-live="polite">1 / 3</p>
        <button className={styles.closeBtn} type="button">닫기</button>
      </div>
    </div>
  );
}