07Full-bleed slideshow with thumbnail strip

<main class="stage">
  <div class="ss-wrap">
    <div class="ss-viewport" tabindex="0" aria-label="Slideshow, use the left and right arrow keys to move">
      <ul class="ss-track is-demo">
        <li class="ss-slide ss-slide--a"></li>
        <li class="ss-slide ss-slide--b"></li>
        <li class="ss-slide ss-slide--c"></li>
        <li class="ss-slide ss-slide--d"></li>
        <li class="ss-slide ss-slide--a" aria-hidden="true"></li>
      </ul>
    </div>
    <div class="ss-thumbs is-demo" role="tablist" aria-label="Choose a slide">
      <button class="ss-thumb ss-thumb--a" type="button" role="tab" aria-label="Photo 1"></button>
      <button class="ss-thumb ss-thumb--b" type="button" role="tab" aria-label="Photo 2"></button>
      <button class="ss-thumb ss-thumb--c" type="button" role="tab" aria-label="Photo 3"></button>
      <button class="ss-thumb ss-thumb--d" type="button" role="tab" aria-label="Photo 4"></button>
    </div>
  </div>
</main>

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

$duration: $dur-loop;                                     // 슬라이드 한 바퀴 도는 시간 (설정 초 값과 일치)
$easing: linear;
$color: $subject-sky;                                      // 활성 썸네일 테두리 색

@include stage($stage-ink);

.ss-wrap { width: min(200px, 78vw); }

.ss-viewport {
  overflow: hidden;
  border-radius: $r-card;
  outline: none;
}
.ss-viewport:focus-visible { outline: 2px solid $color; outline-offset: 2px; }

.ss-track {
  display: flex;
  list-style: none;
  margin: 0 0 $sp-2;
  padding: 0;
  width: 500%;                                              // 실제 4장 + 1번 클론 = 5칸
}
.ss-slide {
  flex: 0 0 20%;
  aspect-ratio: 8 / 5;
  border-radius: $r-card;
}
.ss-slide--a { background: linear-gradient(155deg, $color 0%, $stage-ink 100%); }
.ss-slide--b { background: linear-gradient(205deg, $subject-lilac 0%, $color 100%); }
.ss-slide--c { background: linear-gradient(115deg, $color 0%, $subject-cream 55%); }
.ss-slide--d { background: linear-gradient(250deg, $subject-pink 0%, $color 100%); }

// 클론(5번째 칸)이 1번째와 픽셀 단위로 같은 그러데이션이라, -80% 에서 한 바퀴가 끝나고
// 다음 순간 0% 로 되돌아가도(1번째 실칸) 이어붙인 자리가 안 보인다 — "1번 슬라이드 클론" 기법
.ss-track.is-demo { animation: slide-loop $duration $easing infinite; }
@keyframes slide-loop {
  0%, 18%   { transform: translateX(0%); }
  20%, 38%  { transform: translateX(-20%); }
  40%, 58%  { transform: translateX(-40%); }
  60%, 78%  { transform: translateX(-60%); }
  80%, 100% { transform: translateX(-80%); }
}

.ss-thumbs {
  display: flex;
  gap: $sp-2;
  list-style: none;
  margin: 0;
  padding: 0;
}
.ss-thumb {
  flex: 1 1 0;
  aspect-ratio: 8 / 5;
  border: 2px solid transparent;
  border-radius: $r-sm;
  padding: 0;
  cursor: pointer;
  opacity: .5;
  transition: opacity $duration $easing, border-color $duration $easing;
}
.ss-thumb--a { background: linear-gradient(155deg, $color 0%, $stage-ink 100%); }
.ss-thumb--b { background: linear-gradient(205deg, $subject-lilac 0%, $color 100%); }
.ss-thumb--c { background: linear-gradient(115deg, $color 0%, $subject-cream 55%); }
.ss-thumb--d { background: linear-gradient(250deg, $subject-pink 0%, $color 100%); }
.ss-thumb.is-active, .ss-thumb:focus-visible { opacity: 1; border-color: $color; }

.ss-thumbs.is-demo .ss-thumb--a { animation: thumb-a $duration $easing infinite; }
.ss-thumbs.is-demo .ss-thumb--b { animation: thumb-b $duration $easing infinite; }
.ss-thumbs.is-demo .ss-thumb--c { animation: thumb-c $duration $easing infinite; }
.ss-thumbs.is-demo .ss-thumb--d { animation: thumb-d $duration $easing infinite; }

@keyframes thumb-a {
  0%, 18%, 80%, 100% { opacity: 1; border-color: $color; }
  20%, 78%           { opacity: .5; border-color: transparent; }
}
@keyframes thumb-b {
  20%, 38% { opacity: 1; border-color: $color; }
  0%, 18%, 40%, 100% { opacity: .5; border-color: transparent; }
}
@keyframes thumb-c {
  40%, 58% { opacity: 1; border-color: $color; }
  0%, 38%, 60%, 100% { opacity: .5; border-color: transparent; }
}
@keyframes thumb-d {
  60%, 78% { opacity: 1; border-color: $color; }
  0%, 58%, 80%, 100% { opacity: .5; border-color: transparent; }
}

@media (prefers-reduced-motion: reduce) {
  .ss-thumb { transition: none; }
  .ss-track.is-demo, .ss-thumbs.is-demo .ss-thumb { animation: none; }
}

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);
}

.ss-wrap {
  width: min(200px, 78vw);
}

.ss-viewport {
  overflow: hidden;
  border-radius: 16px;
  outline: none;
}

.ss-viewport:focus-visible {
  outline: 2px solid #6ec8ff;
  outline-offset: 2px;
}

.ss-track {
  display: flex;
  list-style: none;
  margin: 0 0 8px;
  padding: 0;
  width: 500%;
}

.ss-slide {
  flex: 0 0 20%;
  aspect-ratio: 8/5;
  border-radius: 16px;
}

.ss-slide--a {
  background: linear-gradient(155deg, #6ec8ff 0%, #17141a 100%);
}

.ss-slide--b {
  background: linear-gradient(205deg, #b9a0ff 0%, #6ec8ff 100%);
}

.ss-slide--c {
  background: linear-gradient(115deg, #6ec8ff 0%, #fff7e6 55%);
}

.ss-slide--d {
  background: linear-gradient(250deg, #ff9ebb 0%, #6ec8ff 100%);
}

.ss-track.is-demo {
  animation: slide-loop 2s linear infinite;
}

@keyframes slide-loop {
  0%, 18% {
    transform: translateX(0%);
  }
  20%, 38% {
    transform: translateX(-20%);
  }
  40%, 58% {
    transform: translateX(-40%);
  }
  60%, 78% {
    transform: translateX(-60%);
  }
  80%, 100% {
    transform: translateX(-80%);
  }
}
.ss-thumbs {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.ss-thumb {
  flex: 1 1 0;
  aspect-ratio: 8/5;
  border: 2px solid transparent;
  border-radius: 8px;
  padding: 0;
  cursor: pointer;
  opacity: 0.5;
  transition: opacity 2s linear, border-color 2s linear;
}

.ss-thumb--a {
  background: linear-gradient(155deg, #6ec8ff 0%, #17141a 100%);
}

.ss-thumb--b {
  background: linear-gradient(205deg, #b9a0ff 0%, #6ec8ff 100%);
}

.ss-thumb--c {
  background: linear-gradient(115deg, #6ec8ff 0%, #fff7e6 55%);
}

.ss-thumb--d {
  background: linear-gradient(250deg, #ff9ebb 0%, #6ec8ff 100%);
}

.ss-thumb.is-active, .ss-thumb:focus-visible {
  opacity: 1;
  border-color: #6ec8ff;
}

.ss-thumbs.is-demo .ss-thumb--a {
  animation: thumb-a 2s linear infinite;
}

.ss-thumbs.is-demo .ss-thumb--b {
  animation: thumb-b 2s linear infinite;
}

.ss-thumbs.is-demo .ss-thumb--c {
  animation: thumb-c 2s linear infinite;
}

.ss-thumbs.is-demo .ss-thumb--d {
  animation: thumb-d 2s linear infinite;
}

@keyframes thumb-a {
  0%, 18%, 80%, 100% {
    opacity: 1;
    border-color: #6ec8ff;
  }
  20%, 78% {
    opacity: 0.5;
    border-color: transparent;
  }
}
@keyframes thumb-b {
  20%, 38% {
    opacity: 1;
    border-color: #6ec8ff;
  }
  0%, 18%, 40%, 100% {
    opacity: 0.5;
    border-color: transparent;
  }
}
@keyframes thumb-c {
  40%, 58% {
    opacity: 1;
    border-color: #6ec8ff;
  }
  0%, 38%, 60%, 100% {
    opacity: 0.5;
    border-color: transparent;
  }
}
@keyframes thumb-d {
  60%, 78% {
    opacity: 1;
    border-color: #6ec8ff;
  }
  0%, 58%, 80%, 100% {
    opacity: 0.5;
    border-color: transparent;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ss-thumb {
    transition: none;
  }
  .ss-track.is-demo, .ss-thumbs.is-demo .ss-thumb {
    animation: none;
  }
}

(function () {
  var viewport = document.querySelector('.ss-viewport');
  var track = document.querySelector('.ss-track');
  var thumbsWrap = document.querySelector('.ss-thumbs');
  var thumbs = document.querySelectorAll('.ss-thumb');
  var real = 4, current = 0;
  function stop() { track.classList.remove('is-demo'); thumbsWrap.classList.remove('is-demo'); }
  function go(i) {
    stop();
    current = i;
    track.style.transform = 'translateX(-' + (i * 20) + '%)';
    thumbs.forEach(function (t, idx) { t.setAttribute('aria-selected', idx === i ? 'true' : 'false'); t.classList.toggle('is-active', idx === i); });
  }
  thumbs.forEach(function (t, i) { t.addEventListener('click', function () { go(i); }); });
  viewport.addEventListener('keydown', function (e) {
    if (e.key === 'ArrowRight') { go((current + 1) % real); e.preventDefault(); }
    else if (e.key === 'ArrowLeft') { go((current - 1 + real) % real); e.preventDefault(); }
  });
})();

import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./FullscreenSlideshowThumbnailStrip.module.scss";

type ReactKeyboardEvent<T> = { key: string; preventDefault: () => void; currentTarget: T };

export type FullscreenSlideshowThumbnailStripProps = {
  duration?: number;
  easing?: string;
  /** 활성 썸네일 테두리 색 */
  color?: string;
};

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

const TONES = ["a", "b", "c", "d"] as const;

/**
 * 큰 사진 한 장이 자동으로 넘어가고, 화살표 키나 썸네일 클릭으로도 이동할 수 있다.
 * 자동 재생 트랙엔 1번 슬라이드의 클론을 5번째 칸으로 붙여 두어 (vanilla 와 동일한 기법)
 * 한 바퀴 끝(80%)이 1번째(0%)와 같은 그림이라 되돌아가는 지점이 안 보인다.
 */
export default function FullscreenSlideshowThumbnailStrip({
  duration = 2000,
  easing = "linear",
  color = "#6ec8ff",
}: FullscreenSlideshowThumbnailStripProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  const [current, setCurrent] = useState(0);
  const [autoplay, setAutoplay] = useState(true);

  function goTo(i: number) {
    setAutoplay(false);
    setCurrent(i);
  }

  function onKeyDown(e: ReactKeyboardEvent<HTMLDivElement>) {
    if (e.key === "ArrowRight") { goTo((current + 1) % TONES.length); e.preventDefault(); }
    else if (e.key === "ArrowLeft") { goTo((current - 1 + TONES.length) % TONES.length); e.preventDefault(); }
  }

  const trackStyle: Vars = autoplay ? vars : { ...vars, transform: `translateX(-${current * 20}%)` };

  return (
    <div className={styles.wrap} style={vars}>
      <div
        className={styles.viewport}
        tabIndex={0}
        aria-label="Slideshow, use the left and right arrow keys to move"
        onKeyDown={onKeyDown}
      >
        <ul className={`${styles.track} ${autoplay ? styles.autoplay : ""}`} style={trackStyle}>
          {/* 실제 4장 + 1번째 클론(5번째 칸, aria-hidden) — 자동 루프가 이 5칸을 -80%까지 훑는다 */}
          {[...TONES, TONES[0]].map((tone, i) => (
            <li key={i} className={`${styles.slide} ${styles["slide-" + tone]}`} aria-hidden={i === TONES.length} />
          ))}
        </ul>
      </div>
      <div className={styles.thumbs} role="tablist" aria-label="Choose a slide">
        {TONES.map((tone, i) => (
          <button
            key={i}
            type="button"
            role="tab"
            aria-selected={!autoplay && current === i}
            aria-label={`Photo ${i + 1}`}
            className={[
              styles.thumb,
              styles["thumb-" + tone],
              autoplay ? styles["autoThumb-" + tone] : (current === i ? styles.active : ""),
            ].join(" ")}
            onClick={() => goTo(i)}
          />
        ))}
      </div>
    </div>
  );
}