03Fade + slide utility

<main class="stage">
  <p class="lead is-demo">One line is all it takes<br>Tailwind animation</p>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 400ms;
$easing: ease-out;
$color: $subject-cream;

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

.lead {
  margin: 0;
  max-width: min(300px, 88vw);
  color: $color;
  text-align: center;
  font-weight: 700;
  font-size: clamp(18px, 5.2vw, 24px);
  line-height: 1.35;
  font-family: inherit;
  opacity: 0;
  transform: translateY(16px);
}

// 데모: --animate-fade-slide 하나로 문단이 떠오르는 걸 2초마다 반복
.lead.is-demo {
  animation: fade-slide-loop 2s $easing infinite;
}

@keyframes fade-slide-loop {
  0%   { opacity: 0; transform: translateY(16px); }
  22%  { opacity: 1; transform: translateY(0); }
  82%  { opacity: 1; transform: translateY(0); }
  100% { opacity: 0; transform: translateY(16px); }
}

// 실사용: 한 번만
.lead.is-appear {
  animation: fade-slide $duration $easing both;
}

@keyframes fade-slide {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

// ── 접근성 ──────────────────────────────────────────
@media (prefers-reduced-motion: reduce) {
  .lead.is-demo, .lead.is-appear { animation: none; opacity: 1; transform: 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);
}

.lead {
  margin: 0;
  max-width: min(300px, 88vw);
  color: #fff7e6;
  text-align: center;
  font-weight: 700;
  font-size: clamp(18px, 5.2vw, 24px);
  line-height: 1.35;
  font-family: inherit;
  opacity: 0;
  transform: translateY(16px);
}

.lead.is-demo {
  animation: fade-slide-loop 2s ease-out infinite;
}

@keyframes fade-slide-loop {
  0% {
    opacity: 0;
    transform: translateY(16px);
  }
  22% {
    opacity: 1;
    transform: translateY(0);
  }
  82% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: 0;
    transform: translateY(16px);
  }
}
.lead.is-appear {
  animation: fade-slide 400ms ease-out both;
}

@keyframes fade-slide {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .lead.is-demo, .lead.is-appear {
    animation: none;
    opacity: 1;
    transform: none;
  }
}

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

export type FadeSlideLeadProps = {
  children?: string;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function FadeSlideLead({
  children = "One line is all it takes",
  duration = 400,
  easing = "ease-out",
  color = "#fff7e6",
}: FadeSlideLeadProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <p className={styles.lead} style={vars}>
      {children}
    </p>
  );
}