07Word-by-word fade-in

<main class="stage">
  <p class="wf-line is-demo"><span>Here's</span> <span>a</span> <span>quick</span> <span>summary</span> <span>of</span> <span>what</span> <span>changed</span> <span>today.</span></p>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 2s;
$easing: $ease-out;
$color: $subject-ink;

@include stage($stage-orange);

.wf-line {
  width: min(300px, 88vw);
  margin: 0;
  padding: $sp-4 $sp-5;
  border-radius: $r-card;
  box-sizing: border-box;
  background: rgba(255, 255, 255, .14);
  color: $color;
  font: 500 15px/1.6 -apple-system, "Segoe UI", sans-serif;
}

.wf-line span {
  display: inline-block;
}

// 실사용: 토큰이 도착할 때마다 새 <span> 을 붙인다. 데모는 같은 문장을 순서대로 반복한다
@keyframes wf-word {
  0%, 100% { opacity: 0; transform: translateY(6px); }
  15%, 78% { opacity: 1; transform: translateY(0); }
  92%      { opacity: 0; transform: translateY(6px); }
}
.wf-line.is-demo span {
  animation: wf-word $duration $easing infinite;
}
.wf-line.is-demo span:nth-child(1) { animation-delay: 0ms; }
.wf-line.is-demo span:nth-child(2) { animation-delay: 90ms; }
.wf-line.is-demo span:nth-child(3) { animation-delay: 180ms; }
.wf-line.is-demo span:nth-child(4) { animation-delay: 270ms; }
.wf-line.is-demo span:nth-child(5) { animation-delay: 360ms; }
.wf-line.is-demo span:nth-child(6) { animation-delay: 450ms; }
.wf-line.is-demo span:nth-child(7) { animation-delay: 540ms; }
.wf-line.is-demo span:nth-child(8) { animation-delay: 630ms; }

@media (prefers-reduced-motion: reduce) {
  .wf-line.is-demo span {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

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);
}

.wf-line {
  width: min(300px, 88vw);
  margin: 0;
  padding: 16px 20px;
  border-radius: 16px;
  box-sizing: border-box;
  background: rgba(255, 255, 255, 0.14);
  color: #17141a;
  font: 500 15px/1.6 -apple-system, "Segoe UI", sans-serif;
}

.wf-line span {
  display: inline-block;
}

@keyframes wf-word {
  0%, 100% {
    opacity: 0;
    transform: translateY(6px);
  }
  15%, 78% {
    opacity: 1;
    transform: translateY(0);
  }
  92% {
    opacity: 0;
    transform: translateY(6px);
  }
}
.wf-line.is-demo span {
  animation: wf-word 2s ease-out infinite;
}

.wf-line.is-demo span:nth-child(1) {
  animation-delay: 0ms;
}

.wf-line.is-demo span:nth-child(2) {
  animation-delay: 90ms;
}

.wf-line.is-demo span:nth-child(3) {
  animation-delay: 180ms;
}

.wf-line.is-demo span:nth-child(4) {
  animation-delay: 270ms;
}

.wf-line.is-demo span:nth-child(5) {
  animation-delay: 360ms;
}

.wf-line.is-demo span:nth-child(6) {
  animation-delay: 450ms;
}

.wf-line.is-demo span:nth-child(7) {
  animation-delay: 540ms;
}

.wf-line.is-demo span:nth-child(8) {
  animation-delay: 630ms;
}

@media (prefers-reduced-motion: reduce) {
  .wf-line.is-demo span {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

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

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

export interface TokenFadeWordsProps {
  duration?: string;
  easing?: string;
  color?: string;
  words?: string[];
}

const DEFAULT_WORDS = ["Here's", "a", "quick", "summary", "of", "what", "changed", "today."];

export default function TokenFadeWords({
  duration = "2s",
  easing = "ease-out",
  color = "#17141a",
  words = DEFAULT_WORDS,
}: TokenFadeWordsProps) {
  const style: Vars = {
    "--duration": duration,
    "--easing": easing,
    "--color": color,
  };
  return (
    <p className={styles.line} style={style}>
      {words.map((w, i) => (
        <span key={i} className={styles.word} style={{ animationDelay: `${i * 90}ms` }}>
          {w}{" "}
        </span>
      ))}
    </p>
  );
}