04Main image slide swap

<main class="stage">
  <section class="gal is-demo" aria-label="Picking a thumbnail swaps the main image in place">
    <input class="gal__radio" type="radio" name="gal-218" id="gal-1" checked>
    <input class="gal__radio" type="radio" name="gal-218" id="gal-2">
    <input class="gal__radio" type="radio" name="gal-218" id="gal-3">
    <div class="gal__frame">
      <div class="gal__scene gal__scene--1"><span class="gal__tag">Front</span></div>
      <div class="gal__scene gal__scene--2"><span class="gal__tag">Side</span></div>
      <div class="gal__scene gal__scene--3"><span class="gal__tag">Detail</span></div>
    </div>
    <div class="gal__thumbs">
      <label class="gal__thumb gal__thumb--1" for="gal-1">Front</label>
      <label class="gal__thumb gal__thumb--2" for="gal-2">Side</label>
      <label class="gal__thumb gal__thumb--3" for="gal-3">Detail</label>
      <span class="gal__indicator" aria-hidden="true"></span>
    </div>
  </section>
</main>

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

$duration: $dur-base;                             // 이미지가 자리를 바꾸는 시간
$easing: $ease-out;
$color: $subject-blue;                            // 1번 장면 색

@include stage($stage-paper);

.gal { width: 280px; max-width: 100%; }
.gal__radio { position: absolute; opacity: 0; pointer-events: none; }

// ── 큰 이미지 틀: 장면 3장이 겹쳐 있고 translateX 로만 교체된다
.gal__frame {
  position: relative;
  height: clamp(100px, 50vh, 176px);
  border-radius: $r-card;
  overflow: hidden;
  background: rgba(23, 20, 26, .06);
}
.gal__scene {
  position: absolute; inset: 0;
  display: grid;
  place-items: center;
  transform: translateX(110%);
  opacity: 0;
  transition: transform $duration $easing, opacity $duration $easing;
}
.gal__scene--1 { background: linear-gradient(150deg, $color, rgba($color, .35)); }
.gal__scene--2 { background: linear-gradient(150deg, $stage-orange, rgba($stage-orange, .35)); }
.gal__scene--3 { background: linear-gradient(150deg, $stage-ink, rgba($stage-ink, .5)); }
.gal__tag {
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .9);
  font-weight: 800;
  font-size: clamp(12px, 3.4vw, 14px);
  font-family: inherit;
  color: $stage-ink;
}
.gal__scene--1 { transform: translateX(0); opacity: 1; }     // 기본 = 1번

// 라디오로 고르면: 새 장면은 오른쪽에서 들어오고 나머지는 왼쪽으로 빠진다
#gal-1:checked ~ .gal__frame .gal__scene--1 { transform: translateX(0);     opacity: 1; }
#gal-1:checked ~ .gal__frame .gal__scene--2,
#gal-1:checked ~ .gal__frame .gal__scene--3 { transform: translateX(-110%); opacity: 0; }
#gal-2:checked ~ .gal__frame .gal__scene--2 { transform: translateX(0);     opacity: 1; }
#gal-2:checked ~ .gal__frame .gal__scene--1,
#gal-2:checked ~ .gal__frame .gal__scene--3 { transform: translateX(-110%); opacity: 0; }
#gal-3:checked ~ .gal__frame .gal__scene--3 { transform: translateX(0);     opacity: 1; }
#gal-3:checked ~ .gal__frame .gal__scene--1,
#gal-3:checked ~ .gal__frame .gal__scene--2 { transform: translateX(-110%); opacity: 0; }

// ── 썸네일: 고정 폭 셀 3개 + 밑에 움직이는 인디케이터 (transform 만)
.gal__thumbs {
  position: relative;
  display: flex;
  gap: $sp-2;
  justify-content: center;
  margin-top: $sp-3;
  padding-bottom: $sp-2;
}
.gal__thumb {
  box-sizing: border-box;
  width: 88px;
  padding: $sp-2 0;
  border: 2px solid rgba(23, 20, 26, .16);
  border-radius: $r-pill;
  background: $stage-paper;
  font-weight: 700;
  font-size: 12px;
  font-family: inherit;
  color: rgba(23, 20, 26, .7);
  text-align: center;
  cursor: pointer;
  transition: color $dur-quick $easing, border-color $dur-quick $easing;
}
#gal-1:checked ~ .gal__thumbs .gal__thumb--1,
#gal-2:checked ~ .gal__thumbs .gal__thumb--2,
#gal-3:checked ~ .gal__thumbs .gal__thumb--3 { color: $stage-ink; border-color: $stage-ink; }

.gal__indicator {
  position: absolute;
  bottom: 0; left: calc(50% - 140px);                   // 행의 왼쪽 끝 (280px 행 기준)
  width: 88px;
  height: 4px;
  border-radius: $r-pill;
  background: $stage-ink;
  transform: translateX(0);
  transition: transform $duration $easing;
}
#gal-2:checked ~ .gal__thumbs .gal__indicator { transform: translateX(96px); }
#gal-3:checked ~ .gal__thumbs .gal__indicator { transform: translateX(192px); }

// 렌더·갤러리용 자동 루프: 1→2→3→1 을 2초 주기로
.gal.is-demo .gal__scene--1 { animation: s1-loop $dur-loop $easing infinite; }
.gal.is-demo .gal__scene--2 { animation: s2-loop $dur-loop $easing infinite; }
.gal.is-demo .gal__scene--3 { animation: s3-loop $dur-loop $easing infinite; }
.gal.is-demo .gal__indicator { animation: ind-loop $dur-loop $easing infinite; }
.gal.is-demo .gal__thumb--1 { animation: th1 $dur-loop $easing infinite; }
.gal.is-demo .gal__thumb--2 { animation: th2 $dur-loop $easing infinite; }
.gal.is-demo .gal__thumb--3 { animation: th3 $dur-loop $easing infinite; }

@keyframes s1-loop {
  0%, 23%    { transform: translateX(0);     opacity: 1; }
  33%, 88%   { transform: translateX(-110%); opacity: 0; }
  98%, 100%  { transform: translateX(0);     opacity: 1; }
}
@keyframes s2-loop {
  0%, 23%    { transform: translateX(110%);  opacity: 0; }
  33%, 56%   { transform: translateX(0);     opacity: 1; }
  66%, 100%  { transform: translateX(-110%); opacity: 0; }
}
@keyframes s3-loop {
  0%, 56%    { transform: translateX(110%);  opacity: 0; }
  66%, 88%   { transform: translateX(0);     opacity: 1; }
  98%, 100%  { transform: translateX(110%);  opacity: 0; }
}
@keyframes ind-loop {
  0%, 23%    { transform: translateX(0); }
  33%, 56%   { transform: translateX(calc(100% + 8px)); }
  66%, 88%   { transform: translateX(calc(200% + 16px)); }
  98%, 100%  { transform: translateX(0); }
}
@keyframes th1 {                              // 활성 엄지 테두리가 장면과 함께 이동
  0%, 23%    { border-color: $stage-ink; color: $stage-ink; }
  33%, 88%   { border-color: rgba(23, 20, 26, .16); color: rgba(23, 20, 26, .7); }
  98%, 100%  { border-color: $stage-ink; color: $stage-ink; }
}
@keyframes th2 {
  0%, 23%    { border-color: rgba(23, 20, 26, .16); color: rgba(23, 20, 26, .7); }
  33%, 56%   { border-color: $stage-ink; color: $stage-ink; }
  66%, 100%  { border-color: rgba(23, 20, 26, .16); color: rgba(23, 20, 26, .7); }
}
@keyframes th3 {
  0%, 56%    { border-color: rgba(23, 20, 26, .16); color: rgba(23, 20, 26, .7); }
  66%, 88%   { border-color: $stage-ink; color: $stage-ink; }
  98%, 100%  { border-color: rgba(23, 20, 26, .16); color: rgba(23, 20, 26, .7); }
}

@media (max-width: 360px) {          // 320×200 아이프레임 대응
  .gal__frame { height: 100px; }
  .gal__thumb { width: 72px; padding: 4px 0; font-size: 10px; }
  .gal__indicator { width: 72px; left: calc(50% - 116px); }
  #gal-2:checked ~ .gal__thumbs .gal__indicator { transform: translateX(80px); }
  #gal-3:checked ~ .gal__thumbs .gal__indicator { transform: translateX(160px); }
}

@media (prefers-reduced-motion: reduce) {
  .gal__scene, .gal__thumb, .gal__indicator { transition: none; }
  .gal.is-demo .gal__scene,
  .gal.is-demo .gal__indicator,
  .gal.is-demo .gal__thumb { animation: none; }       // 장면·인디케이터가 즉시 바뀐다
}

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);
}

.gal {
  width: 280px;
  max-width: 100%;
}

.gal__radio {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.gal__frame {
  position: relative;
  height: clamp(100px, 50vh, 176px);
  border-radius: 16px;
  overflow: hidden;
  background: rgba(23, 20, 26, 0.06);
}

.gal__scene {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  transform: translateX(110%);
  opacity: 0;
  transition: transform 300ms ease-out, opacity 300ms ease-out;
}

.gal__scene--1 {
  background: linear-gradient(150deg, #2f6df6, rgba(47, 109, 246, 0.35));
}

.gal__scene--2 {
  background: linear-gradient(150deg, #ff4d1f, rgba(255, 77, 31, 0.35));
}

.gal__scene--3 {
  background: linear-gradient(150deg, #17141a, rgba(23, 20, 26, 0.5));
}

.gal__tag {
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.9);
  font-weight: 800;
  font-size: clamp(12px, 3.4vw, 14px);
  font-family: inherit;
  color: #17141a;
}

.gal__scene--1 {
  transform: translateX(0);
  opacity: 1;
}

#gal-1:checked ~ .gal__frame .gal__scene--1 {
  transform: translateX(0);
  opacity: 1;
}

#gal-1:checked ~ .gal__frame .gal__scene--2,
#gal-1:checked ~ .gal__frame .gal__scene--3 {
  transform: translateX(-110%);
  opacity: 0;
}

#gal-2:checked ~ .gal__frame .gal__scene--2 {
  transform: translateX(0);
  opacity: 1;
}

#gal-2:checked ~ .gal__frame .gal__scene--1,
#gal-2:checked ~ .gal__frame .gal__scene--3 {
  transform: translateX(-110%);
  opacity: 0;
}

#gal-3:checked ~ .gal__frame .gal__scene--3 {
  transform: translateX(0);
  opacity: 1;
}

#gal-3:checked ~ .gal__frame .gal__scene--1,
#gal-3:checked ~ .gal__frame .gal__scene--2 {
  transform: translateX(-110%);
  opacity: 0;
}

.gal__thumbs {
  position: relative;
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 12px;
  padding-bottom: 8px;
}

.gal__thumb {
  box-sizing: border-box;
  width: 88px;
  padding: 8px 0;
  border: 2px solid rgba(23, 20, 26, 0.16);
  border-radius: 999px;
  background: #ffffff;
  font-weight: 700;
  font-size: 12px;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.7);
  text-align: center;
  cursor: pointer;
  transition: color 220ms ease-out, border-color 220ms ease-out;
}

#gal-1:checked ~ .gal__thumbs .gal__thumb--1,
#gal-2:checked ~ .gal__thumbs .gal__thumb--2,
#gal-3:checked ~ .gal__thumbs .gal__thumb--3 {
  color: #17141a;
  border-color: #17141a;
}

.gal__indicator {
  position: absolute;
  bottom: 0;
  left: calc(50% - 140px);
  width: 88px;
  height: 4px;
  border-radius: 999px;
  background: #17141a;
  transform: translateX(0);
  transition: transform 300ms ease-out;
}

#gal-2:checked ~ .gal__thumbs .gal__indicator {
  transform: translateX(96px);
}

#gal-3:checked ~ .gal__thumbs .gal__indicator {
  transform: translateX(192px);
}

.gal.is-demo .gal__scene--1 {
  animation: s1-loop 2s ease-out infinite;
}

.gal.is-demo .gal__scene--2 {
  animation: s2-loop 2s ease-out infinite;
}

.gal.is-demo .gal__scene--3 {
  animation: s3-loop 2s ease-out infinite;
}

.gal.is-demo .gal__indicator {
  animation: ind-loop 2s ease-out infinite;
}

.gal.is-demo .gal__thumb--1 {
  animation: th1 2s ease-out infinite;
}

.gal.is-demo .gal__thumb--2 {
  animation: th2 2s ease-out infinite;
}

.gal.is-demo .gal__thumb--3 {
  animation: th3 2s ease-out infinite;
}

@keyframes s1-loop {
  0%, 23% {
    transform: translateX(0);
    opacity: 1;
  }
  33%, 88% {
    transform: translateX(-110%);
    opacity: 0;
  }
  98%, 100% {
    transform: translateX(0);
    opacity: 1;
  }
}
@keyframes s2-loop {
  0%, 23% {
    transform: translateX(110%);
    opacity: 0;
  }
  33%, 56% {
    transform: translateX(0);
    opacity: 1;
  }
  66%, 100% {
    transform: translateX(-110%);
    opacity: 0;
  }
}
@keyframes s3-loop {
  0%, 56% {
    transform: translateX(110%);
    opacity: 0;
  }
  66%, 88% {
    transform: translateX(0);
    opacity: 1;
  }
  98%, 100% {
    transform: translateX(110%);
    opacity: 0;
  }
}
@keyframes ind-loop {
  0%, 23% {
    transform: translateX(0);
  }
  33%, 56% {
    transform: translateX(calc(100% + 8px));
  }
  66%, 88% {
    transform: translateX(calc(200% + 16px));
  }
  98%, 100% {
    transform: translateX(0);
  }
}
@keyframes th1 {
  0%, 23% {
    border-color: #17141a;
    color: #17141a;
  }
  33%, 88% {
    border-color: rgba(23, 20, 26, 0.16);
    color: rgba(23, 20, 26, 0.7);
  }
  98%, 100% {
    border-color: #17141a;
    color: #17141a;
  }
}
@keyframes th2 {
  0%, 23% {
    border-color: rgba(23, 20, 26, 0.16);
    color: rgba(23, 20, 26, 0.7);
  }
  33%, 56% {
    border-color: #17141a;
    color: #17141a;
  }
  66%, 100% {
    border-color: rgba(23, 20, 26, 0.16);
    color: rgba(23, 20, 26, 0.7);
  }
}
@keyframes th3 {
  0%, 56% {
    border-color: rgba(23, 20, 26, 0.16);
    color: rgba(23, 20, 26, 0.7);
  }
  66%, 88% {
    border-color: #17141a;
    color: #17141a;
  }
  98%, 100% {
    border-color: rgba(23, 20, 26, 0.16);
    color: rgba(23, 20, 26, 0.7);
  }
}
@media (max-width: 360px) {
  .gal__frame {
    height: 100px;
  }
  .gal__thumb {
    width: 72px;
    padding: 4px 0;
    font-size: 10px;
  }
  .gal__indicator {
    width: 72px;
    left: calc(50% - 116px);
  }
  #gal-2:checked ~ .gal__thumbs .gal__indicator {
    transform: translateX(80px);
  }
  #gal-3:checked ~ .gal__thumbs .gal__indicator {
    transform: translateX(160px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .gal__scene, .gal__thumb, .gal__indicator {
    transition: none;
  }
  .gal.is-demo .gal__scene,
  .gal.is-demo .gal__indicator,
  .gal.is-demo .gal__thumb {
    animation: none;
  }
}

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

export type ProductImageSwapProps = {
  /** 장면 이름 순서 — 썸네일 라벨과 같다 */
  scenes: string[];
  /** 장면 배경색 순서 (장면 수와 같게) */
  colors?: string[];
  /** 이미지가 자리를 바꾸는 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
};

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

export default function ProductImageSwap({
  scenes,
  colors = ["#2f6df6", "#ff4d1f", "#17141a"],
  duration = 300,
  easing = "ease-out",
}: ProductImageSwapProps) {
  const [active, setActive] = useState(0);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing };

  return (
    <section className={styles.gal} style={vars} aria-label="상품 이미지 갤러리">
      <div className={styles.frame}>
        {scenes.map((name, i) => (
          <div
            key={name}
            className={styles.scene}
            data-active={i === active}
            style={{ background: `linear-gradient(150deg, ${colors[i % colors.length]}, rgba(0,0,0,.25))` }}
          >
            <span className={styles.tag}>{name}</span>
          </div>
        ))}
      </div>
      <div className={styles.thumbs}>
        {scenes.map((name, i) => (
          <button
            key={name}
            type="button"
            className={`${styles.thumb} ${i === active ? styles.thumbOn : ""}`}
            aria-pressed={i === active}
            onClick={() => setActive(i)}
          >
            {name}
          </button>
        ))}
        <span className={styles.indicator} data-index={Math.min(active, 2)} aria-hidden="true" />
      </div>
    </section>
  );
}