02Gradient angle move

<main class="stage">
  <h1 class="spin">Premium Membership</h1>
</main>

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

$duration: $dur-loop;                              // 각도가 한 바퀴(360deg) 도는 시간
$easing: linear;
$color: $subject-ink;                               // 노란 무대와 대비되는 글자 기준 색

@include stage($stage-yellow);

// 각도 자체를 보간 가능한 값으로 등록해야 gradient() 각도 자리를 keyframes 로 돌릴 수 있다
@property --angle {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}

.spin {
  margin: 0;
  font-weight: 800; font-size: clamp(28px, 8.6vw, 46px); line-height: 1.2; font-family: inherit;
  text-align: center;
  --angle: 0deg;
  background: linear-gradient(var(--angle), $color, $stage-orange, $color);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  animation: rotate-angle $duration $easing infinite;
}

@keyframes rotate-angle {
  from { --angle: 0deg; }
  to   { --angle: 360deg; }
}

@media (prefers-reduced-motion: reduce) {
  .spin { animation: none; --angle: 45deg; }
}

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);
}

@property --angle {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}
.spin {
  margin: 0;
  font-weight: 800;
  font-size: clamp(28px, 8.6vw, 46px);
  line-height: 1.2;
  font-family: inherit;
  text-align: center;
  --angle: 0deg;
  background: linear-gradient(var(--angle), #17141a, #ff4d1f, #17141a);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  animation: rotate-angle 2s linear infinite;
}

@keyframes rotate-angle {
  from {
    --angle: 0deg;
  }
  to {
    --angle: 360deg;
  }
}
@media (prefers-reduced-motion: reduce) {
  .spin {
    animation: none;
    --angle: 45deg;
  }
}

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

export type GradientAngleMoveProps = {
  text: string;
  /** 각도가 360deg 한 바퀴 도는 시간 (기본 2000ms) */
  duration?: number;
  easing?: string;
  /** 글자 기준 색 */
  color?: string;
};

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

export default function GradientAngleMove({
  text,
  duration = 2000,
  easing = "linear",
  color = "#17141a",
}: GradientAngleMoveProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return <h1 className={styles.spin} style={vars}>{text}</h1>;
}