03SVG 물결

<main class="stage">
  <div class="waves" aria-hidden="true">
  <div class="layer layer--back">
    <svg class="wave" viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,60 C60,90 120,30 180,60 C240,90 300,30 360,60 C420,90 480,30 480,60 L480,120 L0,120 Z"/></svg>
    <svg class="wave" viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,60 C60,90 120,30 180,60 C240,90 300,30 360,60 C420,90 480,30 480,60 L480,120 L0,120 Z"/></svg>
  </div>
  <div class="layer layer--front">
    <svg class="wave" viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,70 C50,40 130,100 180,70 C240,40 300,100 360,70 C420,40 480,100 480,70 L480,120 L0,120 Z"/></svg>
    <svg class="wave" viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,70 C50,40 130,100 180,70 C240,40 300,100 360,70 C420,40 480,100 480,70 L480,120 L0,120 Z"/></svg>
  </div>
  </div>
  <p class="caption">여름 신상 공개</p>
</main>

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

// ── 변수 3개 ──────────────────────────────
$duration: $dur-loop * 3;   // 6s — 뒤 레이어 한 바퀴
$easing: linear;
$color: $subject-cream;

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

.caption {
  position: absolute; z-index: 1; top: $sp-6; left: $sp-6; margin: 0;
  color: $subject-cream; font-weight: 700; font-size: clamp(16px, 5vw, 22px); line-height: 1; font-family: inherit;
}

// .layer 는 폭 200%로 뷰포트 밖까지 나간다 — 문서 스크롤을 부풀리지 않도록 .waves 로 먼저 가둔다 (BD8)
.waves { position: absolute; inset: 0; overflow: hidden; }

// 물결은 같은 SVG 를 두 장 나란히(각 50%) 붙여 폭 200%로 만들고, 정확히 -50% 만큼 옮기면
// 이어붙인 자리가 서로 같은 그림이라 이음새 없이 반복된다 (마퀴와 같은 원리, flex gap 은 안 쓴다)
.layer {
  position: absolute; left: 0; right: 0; bottom: 0; height: 55%;
  display: flex; width: 200%;
}
.wave { width: 50%; height: 100%; flex: none; display: block; fill: $color; }

.layer--back {
  opacity: .4;
  animation: drift $duration $easing infinite;
}
.layer--front {
  opacity: .85;
  animation: drift ($duration * .65) $easing infinite;
}

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

// ── 접근성: 물결을 멈추고 정지 이미지로 ────────────
@media (prefers-reduced-motion: reduce) {
  .layer { animation: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.caption {
  position: absolute;
  z-index: 1;
  top: 24px;
  left: 24px;
  margin: 0;
  color: #fff7e6;
  font-weight: 700;
  font-size: clamp(16px, 5vw, 22px);
  line-height: 1;
  font-family: inherit;
}

.waves {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.layer {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 55%;
  display: flex;
  width: 200%;
}

.wave {
  width: 50%;
  height: 100%;
  flex: none;
  display: block;
  fill: #fff7e6;
}

.layer--back {
  opacity: 0.4;
  animation: drift 6s linear infinite;
}

.layer--front {
  opacity: 0.85;
  animation: drift 3.9s linear infinite;
}

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

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

export type SvgWaveProps = {
  /** 애니메이션 기준 시간(ms) */
  duration?: number;
  /** CSS easing */
  easing?: string;
  /** 피사체 색 */
  color?: string;
};

type Vars = CSSProperties & { "--i"?: number };

const COUNT = 4;

export default function SvgWave({
  duration = 6000,
  easing = "linear",
  color = "#fff7e6",
}: SvgWaveProps) {
  const vars = {
    "--duration": `${duration}ms`,
    "--easing": easing,
    "--color": color,
  } as CSSProperties;

  return (
    <div className={styles.stage} style={vars}>
      <div className={styles.layerBack}>
        <svg className={styles.wave} viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,60 C60,90 120,30 180,60 C240,90 300,30 360,60 C420,90 480,30 480,60 L480,120 L0,120 Z" /></svg>
        <svg className={styles.wave} viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,60 C60,90 120,30 180,60 C240,90 300,30 360,60 C420,90 480,30 480,60 L480,120 L0,120 Z" /></svg>
      </div>
      <div className={styles.layerFront}>
        <svg className={styles.wave} viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,70 C50,40 130,100 180,70 C240,40 300,100 360,70 C420,40 480,100 480,70 L480,120 L0,120 Z" /></svg>
        <svg className={styles.wave} viewBox="0 0 480 120" preserveAspectRatio="none" aria-hidden="true"><path d="M0,70 C50,40 130,100 180,70 C240,40 300,100 360,70 C420,40 480,100 480,70 L480,120 L0,120 Z" /></svg>
      </div>
    </div>
  );
}