04Corner ribbon fold-unfurl

<main class="stage is-demo">
  <div class="card" aria-label="sale item">
    <div class="thumb"></div>
    <div class="ribbon-mount">
      <span class="ribbon">SALE</span>
    </div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-loop;   // 2s — 펼쳐짐+되감김 한 주기
$easing: $ease-spring;
$color: #ddbebb;        // 캔디 코럴

@include stage($stage-orange);

.card {
  position: relative;
  width: 200px; height: 140px;
  border-radius: $r-card;
  overflow: hidden;
  background: $subject-cream;
  box-shadow: $shadow-raised;
}

.thumb {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba($subject-pink, .18), rgba($subject-lilac, .1));
}

// 213편 리본(빛줄기 스윕)과 다른 메커니즘 — 접힌 리본이 위에서 펼쳐졌다 걷힌다
.ribbon-mount {
  position: absolute;
  top: 0; right: $sp-4;
  width: 56px;
  overflow: visible;
}

.ribbon {
  display: block;
  padding: $sp-2 0 $sp-3;
  background: $color;
  color: #fff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 800;
  font-size: 12px;
  letter-spacing: .06em;
  text-align: center;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 82%, 0 100%);
  box-shadow: $shadow-press;
  transform: scaleY(0) rotate(0deg);
  transform-origin: top center; // 규칙8: 리본 top에서 펼쳐짐
}

.stage.is-demo .ribbon {
  animation: unfurl $duration $easing infinite;
}

@keyframes unfurl {
  0%, 8% { transform: scaleY(0) rotate(0deg); }
  30% { transform: scaleY(1.06) rotate(-2deg); }
  42%, 78% { transform: scaleY(1) rotate(0deg); }
  92%, 100% { transform: scaleY(0) rotate(0deg); }
}

// ── 한 겹: 펼침 안착(42%) 순간 코럴 링 파문 + 리본 색 전이 ──
// unfurl 의 transform 은 그대로 — 링은 .ribbon-mount 에(clip-path 밖이라 잘리지 않음), 색은 리본 배경에
.ribbon-mount { position: absolute; }   // 기존 absolute 재확인 — ::after 기준점

.ribbon-mount::after {
  content: "";
  position: absolute;
  inset: -2px -2px 6px;
  border-radius: $r-xs $r-xs 0 0;
  border: 2px solid rgba($color, 0);
  transform: scale(.92);
  opacity: 0;
  pointer-events: none;
}

.stage.is-demo .ribbon {
  animation: unfurl $duration $easing infinite, ribbon-settle $duration $ease-out infinite;
}
.stage.is-demo .ribbon-mount::after {
  animation: unfurl-ring $duration $easing infinite;
}

@keyframes ribbon-settle {
  0%, 8% { background-color: $color; }
  42% { background-color: mix(#fff, $color, 30%); }
  62%, 100% { background-color: $color; }
}

@keyframes unfurl-ring {
  0%, 30% { transform: scale(.92); opacity: 0; border-color: rgba($color, 0); }
  40% { transform: scale(1); opacity: .75; border-color: rgba(mix(#ffe3d1, $color, 40%), .85); }
  66%, 100% { transform: scale(1.18); opacity: 0; border-color: rgba($color, 0); }
}

@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .ribbon { animation: none; transform: scaleY(1); }
  .stage.is-demo .ribbon-mount::after { animation: none; opacity: 0; }
}

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);
}

.card {
  position: relative;
  width: 200px;
  height: 140px;
  border-radius: 16px;
  overflow: hidden;
  background: #fff7e6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.thumb {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 158, 187, 0.18), rgba(185, 160, 255, 0.1));
}

.ribbon-mount {
  position: absolute;
  top: 0;
  right: 16px;
  width: 56px;
  overflow: visible;
}

.ribbon {
  display: block;
  padding: 8px 0 12px;
  background: #ddbebb;
  color: #fff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 800;
  font-size: 12px;
  letter-spacing: 0.06em;
  text-align: center;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 82%, 0 100%);
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transform: scaleY(0) rotate(0deg);
  transform-origin: top center;
}

.stage.is-demo .ribbon {
  animation: unfurl 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes unfurl {
  0%, 8% {
    transform: scaleY(0) rotate(0deg);
  }
  30% {
    transform: scaleY(1.06) rotate(-2deg);
  }
  42%, 78% {
    transform: scaleY(1) rotate(0deg);
  }
  92%, 100% {
    transform: scaleY(0) rotate(0deg);
  }
}
.ribbon-mount {
  position: absolute;
}

.ribbon-mount::after {
  content: "";
  position: absolute;
  inset: -2px -2px 6px;
  border-radius: 4px 4px 0 0;
  border: 2px solid rgba(221, 190, 187, 0);
  transform: scale(0.92);
  opacity: 0;
  pointer-events: none;
}

.stage.is-demo .ribbon {
  animation: unfurl 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite, ribbon-settle 2s ease-out infinite;
}

.stage.is-demo .ribbon-mount::after {
  animation: unfurl-ring 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes ribbon-settle {
  0%, 8% {
    background-color: #ddbebb;
  }
  42% {
    background-color: rgb(90.6666666667%, 82.1568627451%, 81.3333333333%);
  }
  62%, 100% {
    background-color: #ddbebb;
  }
}
@keyframes unfurl-ring {
  0%, 30% {
    transform: scale(0.92);
    opacity: 0;
    border-color: rgba(221, 190, 187, 0);
  }
  40% {
    transform: scale(1);
    opacity: 0.75;
    border-color: rgba(92%, 80.3137254902%, 76.7843137255%, 0.85);
  }
  66%, 100% {
    transform: scale(1.18);
    opacity: 0;
    border-color: rgba(221, 190, 187, 0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .ribbon {
    animation: none;
    transform: scaleY(1);
  }
  .stage.is-demo .ribbon-mount::after {
    animation: none;
    opacity: 0;
  }
}

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

export type CornerRibbonUnfurlProps = {
  duration?: number;
  easing?: string;
  color?: string;
  label?: string;
};

export default function CornerRibbonUnfurl({
  duration = 2000,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#ff6f61",
  label = "SALE",
}: CornerRibbonUnfurlProps) {
  const vars: CSSProperties = { "--duration": `${duration}ms`, "--easing": easing, "--color": color } as CSSProperties;
  return (
    <div className={styles.card} style={vars} aria-label="sale item">
      <div className={styles.thumb} />
      <div className={styles.mount}>
        <span className={styles.ribbon}>{label}</span>
      </div>
    </div>
  );
}