01Shimmer lines

<main class="stage">
  <div class="lines">
    <div class="line"></div>
    <div class="line"></div>
    <div class="line"></div>
    <div class="line"></div>
  </div>
</main>

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

// ── 변수 3개. 변형은 이것만 바꾼다 ──────────────────────────
$duration: $dur-loop;                            // 빛이 줄 하나를 다 훑는 시간
$easing: $ease-out;                              // 시작은 빠르고 끝은 느리게
$color: $subject-cream;                          // 막대·빛의 바탕 색 (어두운 무대라 크림)

// ── 데모 무대 ──────────────────────────────────────────
@include stage($stage-ink);

.lines {
  width: clamp(180px, 70%, 360px);
  display: grid;
  gap: clamp(10px, 3vw, 16px);
}

// ── 줄 막대 ──────────────────────────────────────────
.line {
  position: relative;
  overflow: hidden;                              // 빛이 막대 밖으로 안 나가게
  height: clamp(12px, 4vw, 16px);
  border-radius: $r-control;
  background: rgba($color, .14);

  &::after {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba($color, .45), transparent);
    transform: translateX(-120%);                // 위치가 아니라 transform 으로만 이동
    animation: shimmer $duration $easing infinite;
  }

  &:nth-child(1) { width: 92%; }
  &:nth-child(2) { width: 100%; }
  &:nth-child(3) { width: 78%; }
  &:nth-child(4) { width: 55%; }

  &:nth-child(2)::after { animation-delay: -140ms; }   // 줄마다 살짝 어긋나게 시작 (음수 지연 = 이미 진행 중인 상태로 시작)
  &:nth-child(3)::after { animation-delay: -280ms; }
  &:nth-child(4)::after { animation-delay: -420ms; }
}

@keyframes shimmer {
  to { transform: translateX(120%); }
}

// ── 접근성: 움직임 줄이기 설정이면 스침 대신 옅은 밝기만 ────────
@media (prefers-reduced-motion: reduce) {
  .line::after { animation: none !important; opacity: .45; 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: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.lines {
  width: clamp(180px, 70%, 360px);
  display: grid;
  gap: clamp(10px, 3vw, 16px);
}

.line {
  position: relative;
  overflow: hidden;
  height: clamp(12px, 4vw, 16px);
  border-radius: 12px;
  background: rgba(255, 247, 230, 0.14);
}
.line::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 247, 230, 0.45), transparent);
  transform: translateX(-120%);
  animation: shimmer 2s ease-out infinite;
}
.line:nth-child(1) {
  width: 92%;
}
.line:nth-child(2) {
  width: 100%;
}
.line:nth-child(3) {
  width: 78%;
}
.line:nth-child(4) {
  width: 55%;
}
.line:nth-child(2)::after {
  animation-delay: -140ms;
}
.line:nth-child(3)::after {
  animation-delay: -280ms;
}
.line:nth-child(4)::after {
  animation-delay: -420ms;
}

@keyframes shimmer {
  to {
    transform: translateX(120%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .line::after {
    animation: none !important;
    opacity: 0.45;
    transform: translateX(0);
  }
}

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

export type ShimmerLinesProps = {
  /** 빛이 줄 하나를 훑는 시간 (기본 2000ms) */
  duration?: number;
  /** CSS easing (기본 ease-out) */
  easing?: string;
  /** 막대·빛의 바탕 색 */
  color?: string;
  /** 줄 수 (기본 4) */
  lines?: number;
  className?: string;
};

const WIDTHS = ["92%", "100%", "78%", "55%"];

export default function ShimmerLines({
  duration = 2000,
  easing = "ease-out",
  color = "#fff7e6",
  lines = 4,
  className = "",
}: ShimmerLinesProps) {
  const vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color } as CSSProperties;
  return (
    <div className={`${styles.lines} ${className}`} style={vars}>
      {Array.from({ length: lines }).map((_, i) => (
        <div
          key={i}
          className={styles.line}
          style={{ width: WIDTHS[i % WIDTHS.length], animationDelay: `${-i * 140}ms` } as CSSProperties}
        />
      ))}
    </div>
  );
}