02Looping slide arrow

<main class="stage">
  <div class="sl-row" aria-hidden="true">
    <span class="sl-chevron sl-chevron--1"></span>
    <span class="sl-chevron sl-chevron--2"></span>
    <span class="sl-chevron sl-chevron--3"></span>
    <span class="sl-trail"></span>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 1.6s;
$easing: $ease-out;
$color: $subject-ink;

@include stage($stage-yellow);

.sl-row {
  display: flex;
  align-items: center;
  gap: $sp-3;
}

.sl-chevron {
  width: 20px;
  height: 20px;
  border-top: 4px solid $color;
  border-right: 4px solid $color;
  transform: rotate(45deg) translateX(-8px);
  opacity: 0;
}

// 실사용·자동재생 공통: 세 개가 짧은 시차를 두고 같은 방향으로 흐른다. 26%에서 살짝 오버슛했다 38%에서 정착한다(고무줄 신장)
@keyframes sl-flow {
  0%   { opacity: 0; transform: rotate(45deg) translateX(-8px); }
  26%  { opacity: 1; transform: rotate(45deg) translateX(3px); }
  38%  { opacity: 1; transform: rotate(45deg) translateX(0); }
  70%  { opacity: 1; transform: rotate(45deg) translateX(0); }
  100% { opacity: 0; transform: rotate(45deg) translateX(8px); }
}
.sl-chevron { animation: sl-flow $duration $easing infinite; }
.sl-chevron--1 { animation-delay: 0ms; }
.sl-chevron--2 { animation-delay: 180ms; }
.sl-chevron--3 { animation-delay: 360ms; }

// 트레일 파티클 — 맨 앞 화살표 뒤로 작은 점 하나가 더 늦게, 더 흐리게 따라간다
.sl-trail {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: $color;
  opacity: 0;
}
@keyframes sl-trail-flow {
  0%   { opacity: 0; transform: translateX(-8px) scale(.5); }
  26%  { opacity: .35; transform: translateX(2px) scale(1); }
  38%  { opacity: .2; transform: translateX(0) scale(.8); }
  70%  { opacity: .2; transform: translateX(0) scale(.8); }
  100% { opacity: 0; transform: translateX(8px) scale(.4); }
}
.sl-trail { animation: sl-trail-flow $duration $easing 540ms infinite; }

@media (prefers-reduced-motion: reduce) {
  .sl-chevron {
    animation: none !important;
    opacity: .6 !important;
    transform: rotate(45deg) translateX(0) !important;
  }
  .sl-trail { animation: none !important; opacity: 0 !important; }
}

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);
}

.sl-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.sl-chevron {
  width: 20px;
  height: 20px;
  border-top: 4px solid #17141a;
  border-right: 4px solid #17141a;
  transform: rotate(45deg) translateX(-8px);
  opacity: 0;
}

@keyframes sl-flow {
  0% {
    opacity: 0;
    transform: rotate(45deg) translateX(-8px);
  }
  26% {
    opacity: 1;
    transform: rotate(45deg) translateX(3px);
  }
  38% {
    opacity: 1;
    transform: rotate(45deg) translateX(0);
  }
  70% {
    opacity: 1;
    transform: rotate(45deg) translateX(0);
  }
  100% {
    opacity: 0;
    transform: rotate(45deg) translateX(8px);
  }
}
.sl-chevron {
  animation: sl-flow 1.6s ease-out infinite;
}

.sl-chevron--1 {
  animation-delay: 0ms;
}

.sl-chevron--2 {
  animation-delay: 180ms;
}

.sl-chevron--3 {
  animation-delay: 360ms;
}

.sl-trail {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #17141a;
  opacity: 0;
}

@keyframes sl-trail-flow {
  0% {
    opacity: 0;
    transform: translateX(-8px) scale(0.5);
  }
  26% {
    opacity: 0.35;
    transform: translateX(2px) scale(1);
  }
  38% {
    opacity: 0.2;
    transform: translateX(0) scale(0.8);
  }
  70% {
    opacity: 0.2;
    transform: translateX(0) scale(0.8);
  }
  100% {
    opacity: 0;
    transform: translateX(8px) scale(0.4);
  }
}
.sl-trail {
  animation: sl-trail-flow 1.6s ease-out 540ms infinite;
}

@media (prefers-reduced-motion: reduce) {
  .sl-chevron {
    animation: none !important;
    opacity: 0.6 !important;
    transform: rotate(45deg) translateX(0) !important;
  }
  .sl-trail {
    animation: none !important;
    opacity: 0 !important;
  }
}

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

export interface LoopingSlideArrowProps {
  duration?: string;
  easing?: string;
  color?: string;
}

export default function LoopingSlideArrow({
  duration = "1.6s",
  easing = "ease-out",
  color = "#17141a",
}: LoopingSlideArrowProps) {
  const style = { "--duration": duration, "--easing": easing, "--color": color } as CSSProperties;
  return (
    <div className={styles.row} style={style} aria-hidden="true">
      <span className={`${styles.chevron} ${styles.c1}`} />
      <span className={`${styles.chevron} ${styles.c2}`} />
      <span className={`${styles.chevron} ${styles.c3}`} />
      <span className={styles.trail} />
    </div>
  );
}