01Infinite-scroll photo wall

<main class="stage">
  <div class="wall-viewport" aria-label="A gallery of photos scrolling endlessly">
    <ul class="wall-track is-demo">
      <li class="wall-tile wall-tile--pink"></li>
      <li class="wall-tile wall-tile--mint"></li>
      <li class="wall-tile wall-tile--lilac"></li>
      <li class="wall-tile wall-tile--sky"></li>
      <li class="wall-tile wall-tile--pink2"></li>
      <li class="wall-tile wall-tile--pink" aria-hidden="true"></li>
      <li class="wall-tile wall-tile--mint" aria-hidden="true"></li>
      <li class="wall-tile wall-tile--lilac" aria-hidden="true"></li>
      <li class="wall-tile wall-tile--sky" aria-hidden="true"></li>
      <li class="wall-tile wall-tile--pink2" aria-hidden="true"></li>
    </ul>
  </div>
</main>

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

$duration: $dur-loop;                                   // 한 바퀴 도는 시간
$easing: linear;
$color: $subject-pink;                                  // 대표 타일 색

@include stage($stage-paper);

.wall-viewport {
  width: min(280px, 84vw);
  overflow: hidden;
  border-radius: $r-card;
  box-shadow: $shadow-press;
}
.wall-track {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  width: max-content;
}
// 간격은 margin-right 로만 준다 (BD15) — flex gap 을 쓰면 -50% 가 gap/2 만큼 모자라 튄다
.wall-tile {
  flex: 0 0 auto;
  width: 56px;
  height: 42px;
  margin-right: $sp-2;
  border-radius: $r-sm;
}
.wall-tile--pink  { background: linear-gradient(155deg, $color 0%, $subject-cream 100%); }
.wall-tile--mint  { background: linear-gradient(155deg, $subject-mint 0%, $subject-cream 100%); }
.wall-tile--lilac { background: linear-gradient(155deg, $subject-lilac 0%, $subject-cream 100%); }
.wall-tile--sky   { background: linear-gradient(155deg, $subject-sky 0%, $subject-cream 100%); }
.wall-tile--pink2 { background: linear-gradient(205deg, $subject-cream 0%, $color 100%); }

// 트랙을 통째로 복제(위 10칸 = 5칸 × 2벌)해 두면 -50% 지점이 처음과 픽셀 단위로 같아 이어붙인 자리가 안 보인다
.wall-track.is-demo { animation: wall-loop $duration $easing infinite; }
@keyframes wall-loop {
  0%   { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

@media (prefers-reduced-motion: reduce) {
  .wall-track.is-demo { animation: 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);
}

.wall-viewport {
  width: min(280px, 84vw);
  overflow: hidden;
  border-radius: 16px;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}

.wall-track {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  width: max-content;
}

.wall-tile {
  flex: 0 0 auto;
  width: 56px;
  height: 42px;
  margin-right: 8px;
  border-radius: 8px;
}

.wall-tile--pink {
  background: linear-gradient(155deg, #ff9ebb 0%, #fff7e6 100%);
}

.wall-tile--mint {
  background: linear-gradient(155deg, #4cd4a6 0%, #fff7e6 100%);
}

.wall-tile--lilac {
  background: linear-gradient(155deg, #b9a0ff 0%, #fff7e6 100%);
}

.wall-tile--sky {
  background: linear-gradient(155deg, #6ec8ff 0%, #fff7e6 100%);
}

.wall-tile--pink2 {
  background: linear-gradient(205deg, #fff7e6 0%, #ff9ebb 100%);
}

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

@keyframes wall-loop {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-50%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .wall-track.is-demo {
    animation: none;
  }
}

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

export type InfiniteScrollPhotoWallProps = {
  /** 한 바퀴 도는 시간 (기본 2000ms) */
  duration?: number;
  easing?: string;
  /** 대표 타일 색 */
  color?: string;
};

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

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

/** 작은 사진들이 가로로 끝없이 흐르고, 트랙을 통째로 복제해 이어붙인 자리가 안 보인다 */
export default function InfiniteScrollPhotoWall({
  duration = 2000,
  easing = "linear",
  color = "#ff9ebb",
}: InfiniteScrollPhotoWallProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <div className={styles.viewport} style={vars} aria-label="A gallery of photos scrolling endlessly">
      <ul className={styles.track}>
        {ORDER.map((tone, i) => (
          <li key={i} className={`${styles.tile} ${styles["tile-" + tone]}`} aria-hidden={i >= 5} />
        ))}
      </ul>
    </div>
  );
}