07Full-bleed aurora band

<main class="stage">
  <section class="cta-a">
    <h3 class="cta-a__title">Start right now</h3>
    <button class="cta-a__btn" type="button">Start for free</button>
  </section>
</main>

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

$duration: $dur-loop;
$easing: linear;
$color: $subject-blue;

@include stage($stage-orange);
.stage { padding: clamp(8px, 4vw, 24px); }

// 오로라 그라디언트가 화면 폭 전체를 흐르고, 그 위에 그레인이 얹힌다
.cta-a {
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  width: clamp(260px, 90vw, 420px);
  border-radius: $r-card;
  padding: $sp-8 $sp-6;
  background: linear-gradient(120deg, $stage-ink, $color, $stage-orange, $stage-yellow, $stage-ink);
  background-size: 300% 100%;
  animation: flow $duration $easing infinite;
}
.cta-a::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .3;
  mix-blend-mode: overlay;
  background-image:
    radial-gradient(rgba($stage-paper, .6) .5px, transparent .5px),
    radial-gradient(rgba($stage-ink, .6) .5px, transparent .5px);
  background-size: 3px 3px, 5px 5px;
}
.cta-a__title { position: relative; z-index: 1; margin: 0 0 $sp-4; color: $stage-paper; font: 700 clamp(16px, 4vw, 20px)/1.3 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif; }
.cta-a__btn { position: relative; z-index: 1; border: 0; border-radius: $r-pill; background: $stage-paper; color: $stage-ink; padding: $sp-2 $sp-6; font-weight: 700; font-size: clamp(11px, 2.6vw, 13px); line-height: 1; }

@keyframes flow { 0% { background-position: 0% 50%; } 100% { background-position: 100% 50%; } }

@media (prefers-reduced-motion: reduce) {
  .cta-a { animation: none; background-position: 0% 50%; }
}

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);
}

.stage {
  padding: clamp(8px, 4vw, 24px);
}

.cta-a {
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  width: clamp(260px, 90vw, 420px);
  border-radius: 16px;
  padding: 32px 24px;
  background: linear-gradient(120deg, #17141a, #2f6df6, #ff4d1f, #ffd23f, #17141a);
  background-size: 300% 100%;
  animation: flow 2s linear infinite;
}

.cta-a::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.3;
  mix-blend-mode: overlay;
  background-image: radial-gradient(rgba(255, 255, 255, 0.6) 0.5px, transparent 0.5px), radial-gradient(rgba(23, 20, 26, 0.6) 0.5px, transparent 0.5px);
  background-size: 3px 3px, 5px 5px;
}

.cta-a__title {
  position: relative;
  z-index: 1;
  margin: 0 0 16px;
  color: #ffffff;
  font: 700 clamp(16px, 4vw, 20px)/1.3 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.cta-a__btn {
  position: relative;
  z-index: 1;
  border: 0;
  border-radius: 999px;
  background: #ffffff;
  color: #17141a;
  padding: 8px 24px;
  font-weight: 700;
  font-size: clamp(11px, 2.6vw, 13px);
  line-height: 1;
}

@keyframes flow {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 100% 50%;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cta-a {
    animation: none;
    background-position: 0% 50%;
  }
}

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

export type AuroraCtaBandProps = {
  title?: string;
  cta?: string;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function AuroraCtaBand({
  title = "Start right now",
  cta = "Start for free",
  duration = 2000,
  easing = "linear",
  color = "#2f6df6",
}: AuroraCtaBandProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <section className={styles.band} style={vars}>
      <h3 className={styles.title}>{title}</h3>
      <button type="button" className={styles.btn}>{cta}</button>
    </section>
  );
}