02::scroll-marker dots

<main class="stage">
  <div class="dm is-demo">
    <div class="dm__viewport">
      <div class="dm__track">
        <div class="dm__slide dm__slide--1"><span class="dm__cap">Summer Lookbook</span></div>
        <div class="dm__slide dm__slide--2"><span class="dm__cap">Wishlist</span></div>
        <div class="dm__slide dm__slide--3"><span class="dm__cap">Flash Sale</span></div>
        <div class="dm__slide dm__slide--1 dm__slide--clone" aria-hidden="true"><span class="dm__cap">Summer Lookbook</span></div>
      </div>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-base;
$easing: $ease-spring;
$color: $stage-orange;                // 활성 점 색

@include stage($stage-yellow);

.dm { width: min(340px, 82vw); overflow: hidden; border-radius: $r-card; }

// ── 실제 동작: scroll-marker-group + ::scroll-marker 가 점을 만들고 이동시킨다 (0줄 JS) ──
.dm__viewport {
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-marker-group: after;
  scrollbar-width: none;
  &::-webkit-scrollbar { display: none; }
}
.dm__viewport::scroll-marker-group {
  display: flex;
  justify-content: center;
  gap: $sp-2;
  margin-top: $sp-2;
}
// ── 무한 루프 이음새: 1번을 트랙 끝에 복제(aria-hidden). 점은 복제분만 숨긴다 ──
.dm__track {
  display: flex;
  width: 400%;
}
.dm__slide {
  flex: 0 0 25%;
  scroll-snap-align: start;
  aspect-ratio: 16 / 10;
  margin-right: $sp-3;
  border-radius: $r-card;
  position: relative;
  overflow: hidden;
  display: grid;
  place-items: end start;
  box-sizing: border-box;

  &::scroll-marker {
    content: "";
    width: $sp-2; height: $sp-2;
    border-radius: 50%;
    background: rgba(23, 20, 26, .28);
    transition: background $duration $easing, transform $duration $easing;
  }
  &::scroll-marker:target-current {
    background: $color;
    transform: scale(1.35);
  }
}
.dm__slide--clone::scroll-marker { display: none; }
.dm__slide:last-child { margin-right: 0; }
// 플레이스홀더 "사진"
.dm__slide::before {
  content: ""; position: absolute; top: $sp-4; right: $sp-4;
  width: $sp-10; height: $sp-10; border-radius: 50%;
  background: rgba(255, 255, 255, .85);
}
.dm__slide::after {
  content: ""; position: absolute; left: -8%; right: -8%; bottom: -6%; height: 52%;
  background: rgba(23, 20, 26, .26);
  clip-path: polygon(0% 100%, 20% 38%, 40% 64%, 58% 24%, 76% 58%, 100% 32%, 100% 100%);
}
.dm__slide--1 { background: linear-gradient(135deg, $subject-blue, #d6ddeb); }
.dm__slide--2 { background: linear-gradient(135deg, $color, #ebdbd6); }
.dm__slide--3 { background: linear-gradient(135deg, $subject-ink, #4a3f5c); }
.dm__cap {
  position: relative; z-index: 1;
  margin: $sp-4;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .38);
  color: $subject-cream;
  font-weight: 600;
  font-size: clamp(12px, 3.2vw, 14px);
  line-height: 1;
  font-family: inherit;
}

// ── 데모 루프: 트랙에 별도 transform 을 얹어 자동으로 넘어간다 (진짜 스크롤·점 클릭은 그대로) ──
// 마지막 칸은 1번의 복제본 — 그곳까지 정상 속도로 가고 100%→0% 점프는 복제본=1번이라 안 보인다 (텔레포트 금지)
.dm.is-demo .dm__track { animation: dm-loop $dur-loop $easing infinite; }
@keyframes dm-loop {
  0%, 8%    { transform: translateX(0%); }
  31%, 39%  { transform: translateX(calc(-25% - #{$sp-3})); }
  62%, 70%  { transform: translateX(calc(-50% - #{$sp-3 * 2})); }
  92%, 100% { transform: translateX(calc(-75% - #{$sp-3 * 3})); }
}

// ── 접근성 ──────────────────────────────────────────
@media (prefers-reduced-motion: reduce) {
  .dm.is-demo .dm__track { animation: none !important; }
  .dm__slide::scroll-marker { transition: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.dm {
  width: min(340px, 82vw);
  overflow: hidden;
  border-radius: 16px;
}

.dm__viewport {
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-marker-group: after;
  scrollbar-width: none;
}
.dm__viewport::-webkit-scrollbar {
  display: none;
}

.dm__viewport::scroll-marker-group {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 8px;
}

.dm__track {
  display: flex;
  width: 400%;
}

.dm__slide {
  flex: 0 0 25%;
  scroll-snap-align: start;
  aspect-ratio: 16/10;
  margin-right: 12px;
  border-radius: 16px;
  position: relative;
  overflow: hidden;
  display: grid;
  place-items: end start;
  box-sizing: border-box;
}
.dm__slide::scroll-marker {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(23, 20, 26, 0.28);
  transition: background 300ms cubic-bezier(0.2, 0.8, 0.2, 1), transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.dm__slide::scroll-marker:target-current {
  background: #ff4d1f;
  transform: scale(1.35);
}

.dm__slide--clone::scroll-marker {
  display: none;
}

.dm__slide:last-child {
  margin-right: 0;
}

.dm__slide::before {
  content: "";
  position: absolute;
  top: 16px;
  right: 16px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.85);
}

.dm__slide::after {
  content: "";
  position: absolute;
  left: -8%;
  right: -8%;
  bottom: -6%;
  height: 52%;
  background: rgba(23, 20, 26, 0.26);
  clip-path: polygon(0% 100%, 20% 38%, 40% 64%, 58% 24%, 76% 58%, 100% 32%, 100% 100%);
}

.dm__slide--1 {
  background: linear-gradient(135deg, #2f6df6, #d6ddeb);
}

.dm__slide--2 {
  background: linear-gradient(135deg, #ff4d1f, #ebdbd6);
}

.dm__slide--3 {
  background: linear-gradient(135deg, #17141a, #4a3f5c);
}

.dm__cap {
  position: relative;
  z-index: 1;
  margin: 16px;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.38);
  color: #fff7e6;
  font-weight: 600;
  font-size: clamp(12px, 3.2vw, 14px);
  line-height: 1;
  font-family: inherit;
}

.dm.is-demo .dm__track {
  animation: dm-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes dm-loop {
  0%, 8% {
    transform: translateX(0%);
  }
  31%, 39% {
    transform: translateX(calc(-25% - 12px));
  }
  62%, 70% {
    transform: translateX(calc(-50% - 24px));
  }
  92%, 100% {
    transform: translateX(calc(-75% - 36px));
  }
}
@media (prefers-reduced-motion: reduce) {
  .dm.is-demo .dm__track {
    animation: none !important;
  }
  .dm__slide::scroll-marker {
    transition: none;
  }
}

// 점(dot) 자체는 브라우저가 ::scroll-marker 로 자동 생성한다(0줄).
// 이 3줄은 미리보기 자동 재생만 멈춘다 — 실제로는 점을 눌러도, 슬라이드를 드래그해도 그대로 동작한다.
document.querySelector('.dm__viewport').addEventListener('pointerdown', function () {
  document.querySelector('.dm').classList.remove('is-demo');
});

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

const SLIDES = ["여름 룩북", "위시리스트", "할인 특가"];

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

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

export default function DotsScrollMarker({ duration = 300, easing = "cubic-bezier(.2,.8,.2,1)", color = "#ff4d1f" }: DotsScrollMarkerProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <div className={styles.dm} style={vars}>
      {/* 점(dot)은 브라우저가 ::scroll-marker 로 자동 생성한다 — React 상태 없이 CSS 만으로 */}
      <div className={styles.viewport}>
        <div className={styles.track}>
          {SLIDES.map((label, i) => (
            <div key={label} className={`${styles.slide} ${styles["slide" + (i + 1)]}`}>
              <span className={styles.cap}>{label}</span>
            </div>
          ))}
        </div>
      </div>
    </div>
  );
}