02Nền gradient trôi chậm

<main class="stage is-demo">
  <section class="hero">
    <p class="hero__eyebrow">New arrival</p>
    <h1 class="hero__title">Build in color.</h1>
  </section>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;   // 2s — 그라디언트 한 바퀴 드리프트
$easing: $ease-out;
$color: $subject-ink;

@include stage($stage-yellow);

.hero {
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  width: clamp(220px, 62vmin, 300px);
  aspect-ratio: 4 / 3;
  border-radius: $r-card;
  background: $color;
  padding: $sp-6;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: $sp-2;
}

// 카드보다 훨씬 큰(180% 오버사이즈) conic-gradient 층 — overflow:hidden 이 가둔다
.hero::before {
  content: '';
  position: absolute;
  inset: -60% -60%;
  background: conic-gradient(from 0deg, #d5a9b6, #a994ca, #a3c6d1, #d5a9b6);
  opacity: .55;
  pointer-events: none;
}

.hero__eyebrow, .hero__title { position: relative; z-index: 1; margin: 0; color: $subject-cream; }
.hero__eyebrow { font-weight: 700; font-size: clamp(11px, 3vw, 12px); line-height: 1; font-family: inherit; letter-spacing: .08em; text-transform: uppercase; }
.hero__title { font-weight: 800; font-size: clamp(22px, 6vw, 30px); line-height: 1.2; font-family: inherit; }

// translate·rotate 만 — background-position 은 쓰지 않는다
.stage.is-demo .hero::before { animation: drift $duration $easing infinite; }

@keyframes drift {
  0%   { transform: translate(-6%, -4%) rotate(0deg); }
  50%  { transform: translate(6%, 5%) rotate(180deg); }
  100% { transform: translate(-6%, -4%) rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .hero::before { animation: none; transform: 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);
}

.hero {
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  width: clamp(220px, 62vmin, 300px);
  aspect-ratio: 4/3;
  border-radius: 16px;
  background: #17141a;
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 8px;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -60% -60%;
  background: conic-gradient(from 0deg, #d5a9b6, #a994ca, #a3c6d1, #d5a9b6);
  opacity: 0.55;
  pointer-events: none;
}

.hero__eyebrow, .hero__title {
  position: relative;
  z-index: 1;
  margin: 0;
  color: #fff7e6;
}

.hero__eyebrow {
  font-weight: 700;
  font-size: clamp(11px, 3vw, 12px);
  line-height: 1;
  font-family: inherit;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero__title {
  font-weight: 800;
  font-size: clamp(22px, 6vw, 30px);
  line-height: 1.2;
  font-family: inherit;
}

.stage.is-demo .hero::before {
  animation: drift 2s ease-out infinite;
}

@keyframes drift {
  0% {
    transform: translate(-6%, -4%) rotate(0deg);
  }
  50% {
    transform: translate(6%, 5%) rotate(180deg);
  }
  100% {
    transform: translate(-6%, -4%) rotate(360deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .hero::before {
    animation: none;
    transform: none;
  }
}

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

export type GradientBgDriftProps = {
  eyebrow?: string;
  title?: string;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function GradientBgDrift({
  eyebrow = "New arrival",
  title = "Build in color.",
  duration = 2000,
  easing = "ease-out",
  color = "#17141a",
}: GradientBgDriftProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <section className={styles.hero} style={vars}>
      <p className={styles.eyebrow}>{eyebrow}</p>
      <h1 className={styles.title}>{title}</h1>
    </section>
  );
}