083D curved marquee

<main class="stage">
  <div class="marquee">
    <div class="marquee__track">
      <span class="marquee__card"></span>
      <span class="marquee__card"></span>
      <span class="marquee__card"></span>
      <span class="marquee__card"></span>
      <span class="marquee__card"></span>
      <span class="marquee__card" aria-hidden="true"></span>
      <span class="marquee__card" aria-hidden="true"></span>
      <span class="marquee__card" aria-hidden="true"></span>
      <span class="marquee__card" aria-hidden="true"></span>
      <span class="marquee__card" aria-hidden="true"></span>
    </div>
  </div>
</main>

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

$duration: $dur-loop;
$easing: linear;
$color: $subject-blue;

@include stage($stage-paper);
.stage { perspective: 420px; }

.marquee {
  width: min(300px, 80vw);
  overflow: hidden;
}
.marquee__track {
  display: flex;
  width: max-content;
  transform-style: preserve-3d;
  animation: marquee-scroll $duration $easing infinite;
}
.marquee__card {
  margin-right: 8px;   // 트랙의 gap 대신 — 세트 폭이 정확히 절반이 되어 -50% 이음새가 0px 이 된다
  flex-shrink: 0;
  width: 40px;
  height: 64px;
  border-radius: $r-control;
  background: $color;
  box-shadow: $shadow-press;
  transform-style: preserve-3d;
}

// 카드 5장을 부채꼴로 기울여 원통 벽처럼 보이게 한다 — 같은 각도 표를 복제본(6~10번째)에도 그대로 반복해
// 이음매에서 곡률이 끊기지 않는다
@for $i from 1 through 10 {
  $step: ($i - 1) % 5;
  .marquee__card:nth-child(#{$i}) {
    transform: rotateY(#{($step - 2) * 22}deg) translateZ(#{-1 * (2 - if($step > 2, 4 - $step, $step)) * 20}px);
  }
}

@keyframes marquee-scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

@media (prefers-reduced-motion: reduce) {
  .marquee__track { animation: none; transform: translateX(0); }
}

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);
}

.stage {
  perspective: 420px;
}

.marquee {
  width: min(300px, 80vw);
  overflow: hidden;
}

.marquee__track {
  display: flex;
  width: max-content;
  transform-style: preserve-3d;
  animation: marquee-scroll 2s linear infinite;
}

.marquee__card {
  margin-right: 8px;
  flex-shrink: 0;
  width: 40px;
  height: 64px;
  border-radius: 12px;
  background: #2f6df6;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transform-style: preserve-3d;
}

.marquee__card:nth-child(1) {
  transform: rotateY(-44deg) translateZ(-40px);
}

.marquee__card:nth-child(2) {
  transform: rotateY(-22deg) translateZ(-20px);
}

.marquee__card:nth-child(3) {
  transform: rotateY(0deg) translateZ(-0px);
}

.marquee__card:nth-child(4) {
  transform: rotateY(22deg) translateZ(-20px);
}

.marquee__card:nth-child(5) {
  transform: rotateY(44deg) translateZ(-40px);
}

.marquee__card:nth-child(6) {
  transform: rotateY(-44deg) translateZ(-40px);
}

.marquee__card:nth-child(7) {
  transform: rotateY(-22deg) translateZ(-20px);
}

.marquee__card:nth-child(8) {
  transform: rotateY(0deg) translateZ(-0px);
}

.marquee__card:nth-child(9) {
  transform: rotateY(22deg) translateZ(-20px);
}

.marquee__card:nth-child(10) {
  transform: rotateY(44deg) translateZ(-40px);
}

@keyframes marquee-scroll {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-50%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .marquee__track {
    animation: none;
    transform: translateX(0);
  }
}

import type { CSSProperties } from "react";
import styles from "./Curved3DMarquee.module.scss";

export type Curved3DMarqueeProps = {
  count?: number;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function Curved3DMarquee({
  count = 5,
  duration = 12000,
  easing = "linear",
  color = "#2f6df6",
}: Curved3DMarqueeProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  const cards = Array.from({ length: count * 2 });

  return (
    <div className={styles.stage3d}>
      <div className={styles.marquee} style={vars}>
        <div className={styles.track}>
          {cards.map((_, i) => (
            <span key={i} className={styles.card} aria-hidden={i >= count} />
          ))}
        </div>
      </div>
    </div>
  );
}