08Tailwind v4 --easeトークン

<main class="stage is-demo">
  <div class="track">
    <span class="dot dot--start"></span>
    <span class="dot dot--end"></span>
    <div class="puck"></div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;   // 2s
$easing: var(--ease-spring);   // 실제로 움직이는 값은 :root 커스텀 프로퍼티에 있다
$color: $subject-blue;

// Tailwind v4 는 @theme 블록에 --ease-* 를 등록하면 ease-(--ease-spring) 유틸이 생긴다.
// 이 zip 은 Tailwind 를 불러오지 않으므로(외부 의존 0), 같은 패턴을 순수 CSS 커스텀 프로퍼티로만 재현했다
:root {
  --ease-spring: cubic-bezier(.34, 1.56, .64, 1);
}

@include stage($stage-paper);

$track-w: 220px;
$puck-w: $sp-6;
$travel: $track-w - $puck-w;

.track {
  position: relative;
  width: $track-w;
  height: $sp-2;
}

.dot {
  position: absolute;
  top: 50%;
  width: $sp-2;
  height: $sp-2;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .18);
  transform: translate(-50%, -50%);
}
.dot--start { left: 0; }
.dot--end { left: $track-w; }

.puck {
  position: absolute;
  top: 50%;
  left: 0;
  width: $puck-w;
  height: $puck-w;
  border-radius: $r-pill;
  background: $color;
  box-shadow: $shadow-raised;
  transform: translate(0, -50%);
}

.stage.is-demo .puck {
  animation: move $duration $easing infinite alternate;
}

@keyframes move {
  from { transform: translate(0, -50%); }
  to   { transform: translate($travel, -50%); }
}

@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .puck { animation: none; transform: translate($travel, -50%); }
}

:root {
  --ease-spring: cubic-bezier(.34, 1.56, .64, 1);
}

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

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

.track {
  position: relative;
  width: 220px;
  height: 8px;
}

.dot {
  position: absolute;
  top: 50%;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.18);
  transform: translate(-50%, -50%);
}

.dot--start {
  left: 0;
}

.dot--end {
  left: 220px;
}

.puck {
  position: absolute;
  top: 50%;
  left: 0;
  width: 24px;
  height: 24px;
  border-radius: 999px;
  background: #2f6df6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transform: translate(0, -50%);
}

.stage.is-demo .puck {
  animation: move 2s var(--ease-spring) infinite alternate;
}

@keyframes move {
  from {
    transform: translate(0, -50%);
  }
  to {
    transform: translate(196px, -50%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .puck {
    animation: none;
    transform: translate(196px, -50%);
  }
}

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

export type TailwindEaseTokenProps = {
  duration?: number;
  color?: string;
};

// Tailwind v4 는 @theme 에 --ease-spring 을 등록하면 ease-(--ease-spring) 유틸이 생긴다.
// 이 컴포넌트는 Tailwind 를 불러오지 않고(외부 의존 0) 같은 --ease-* 커스텀 프로퍼티 패턴만 재현한다
export default function TailwindEaseToken({ duration = 2000, color = "#2f6df6" }: TailwindEaseTokenProps) {
  const vars: CSSProperties = {
    "--duration": `${duration}ms`,
    "--color": color,
    "--ease-spring": "cubic-bezier(.34, 1.56, .64, 1)",
  } as CSSProperties;
  return (
    <div className={styles.stage} style={vars}>
      <div className={styles.track}>
        <span className={`${styles.dot} ${styles.dotStart}`} />
        <span className={`${styles.dot} ${styles.dotEnd}`} />
        <div className={styles.puck} />
      </div>
    </div>
  );
}