03Flip to reveal back

<main class="stage">
  <article class="card is-demo" tabindex="0">
    <div class="card__flip">
      <div class="card__face card__face--front">
        <h3 class="card__title">Pro plan</h3>
        <p class="card__meta">12,000 KRW/mo</p>
      </div>
      <div class="card__face card__face--back">
        <p class="card__back-text">Unlimited exports<br>Up to 5 teammates</p>
      </div>
    </div>
  </article>
</main>

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

$duration: $dur-base;                                  // 뒤집히는 시간
$easing: $ease-spring;
$color: $subject-blue;                                  // 뒷면 배경

@include stage($stage-orange);
.stage { padding: clamp(8px, 2.4vw, 16px); }

.card {
  width: min(150px, 48vw);
  aspect-ratio: 4 / 3;
  perspective: 800px;
  outline: none;
  cursor: pointer;
  border-radius: $r-card;
}
.card__flip {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform $duration $easing;
  border-radius: $r-card;
}
.card__face {
  position: absolute; inset: 0;
  backface-visibility: hidden;
  border-radius: $r-card;
  padding: $sp-3;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.card__face--front { background: $stage-paper; box-shadow: $shadow-press; }
.card__face--back { background: $color; transform: rotateY(180deg); color: $stage-paper; }
.card__title { margin: 0 0 $sp-1; font-weight: 700; font-size: clamp(11px, 3.2vw, 13px); line-height: 1.3; font-family: inherit; color: $stage-ink; }
.card__meta { margin: 0; font-weight: 500; font-size: clamp(10px, 2.8vw, 11px); line-height: 1.3; font-family: inherit; color: rgba($stage-ink, .65); }
.card__back-text { margin: 0; font-weight: 600; font-size: clamp(11px, 3vw, 12px); line-height: 1.5; font-family: inherit; }

.card:hover .card__flip,
.card:focus-visible .card__flip,
.card:active .card__flip {
  transform: rotateY(180deg);
}
.card.is-demo .card__flip { animation: flip-loop $dur-loop $easing infinite; }
@keyframes flip-loop {
  0%, 20%  { transform: rotateY(0); }
  50%, 75% { transform: rotateY(180deg); }
  100%     { transform: rotateY(0); }
}

@media (prefers-reduced-motion: reduce) {
  .card__flip { transition: none; }
  .card.is-demo .card__flip { animation: none; 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);
}

.stage {
  padding: clamp(8px, 2.4vw, 16px);
}

.card {
  width: min(150px, 48vw);
  aspect-ratio: 4/3;
  perspective: 800px;
  outline: none;
  cursor: pointer;
  border-radius: 16px;
}

.card__flip {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
  border-radius: 16px;
}

.card__face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 16px;
  padding: 12px;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.card__face--front {
  background: #ffffff;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}

.card__face--back {
  background: #2f6df6;
  transform: rotateY(180deg);
  color: #ffffff;
}

.card__title {
  margin: 0 0 4px;
  font-weight: 700;
  font-size: clamp(11px, 3.2vw, 13px);
  line-height: 1.3;
  font-family: inherit;
  color: #17141a;
}

.card__meta {
  margin: 0;
  font-weight: 500;
  font-size: clamp(10px, 2.8vw, 11px);
  line-height: 1.3;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.65);
}

.card__back-text {
  margin: 0;
  font-weight: 600;
  font-size: clamp(11px, 3vw, 12px);
  line-height: 1.5;
  font-family: inherit;
}

.card:hover .card__flip,
.card:focus-visible .card__flip,
.card:active .card__flip {
  transform: rotateY(180deg);
}

.card.is-demo .card__flip {
  animation: flip-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes flip-loop {
  0%, 20% {
    transform: rotateY(0);
  }
  50%, 75% {
    transform: rotateY(180deg);
  }
  100% {
    transform: rotateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .card__flip {
    transition: none;
  }
  .card.is-demo .card__flip {
    animation: none;
    transform: none;
  }
}

import type { CSSProperties, ReactNode } from "react";
import styles from "./FlipRevealCard.module.scss";

export type FlipRevealCardProps = {
  title: string;
  meta: string;
  back: ReactNode;
  /** 뒤집히는 시간 (기본 300ms) */
  duration?: number;
  easing?: string;
  /** 뒷면 배경 */
  color?: string;
};

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

export default function FlipRevealCard({
  title,
  meta,
  back,
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#2f6df6",
}: FlipRevealCardProps) {
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  return (
    <article className={styles.card} style={vars} tabIndex={0}>
      <div className={styles.flip}>
        <div className={`${styles.face} ${styles.faceFront}`}>
          <h3 className={styles.title}>{title}</h3>
          <p className={styles.meta}>{meta}</p>
        </div>
        <div className={`${styles.face} ${styles.faceBack}`}>{back}</div>
      </div>
    </article>
  );
}