02縦に反転（クリック）

<main class="stage">
  <button type="button" class="fx-card is-demo" aria-pressed="false">
    <span class="fx-card__inner">
      <span class="fx-card__face fx-card__face--front">Q</span>
      <span class="fx-card__face fx-card__face--back">A</span>
    </span>
  </button>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: $dur-enter;
$easing: $ease-spring;
$color: $subject-ink;

@include stage($stage-yellow);

.fx-card {
  perspective: 700px;
  width: 132px;
  height: 132px;
  border: 0;
  padding: 0;
  background: none;
  cursor: pointer;
  display: block;
}
.fx-card:focus-visible { outline: 3px solid $subject-ink; outline-offset: $sp-1; }

.fx-card__inner {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform $duration $easing;
}
.fx-card.is-flipped .fx-card__inner { transform: rotateX(180deg); }

.fx-card__face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: $r-card;
  backface-visibility: hidden;
  font: 700 34px/1 -apple-system, "Segoe UI", sans-serif;
  color: $subject-cream;
}
.fx-card__face--front { background: $color; }
.fx-card__face--back { background: rgba(23, 20, 26, .8); transform: rotateX(180deg); }

// 데모 루프: 실제 클릭 상태와 별개로 is-demo 가 같은 회전을 무한 재생
@keyframes fx-flip {
  0%, 40% { transform: rotateX(0); }
  60%, 100% { transform: rotateX(180deg); }
}
.fx-card.is-demo .fx-card__inner { animation: fx-flip $duration * 2 $easing infinite; }

@media (prefers-reduced-motion: reduce) {
  .fx-card.is-flipped .fx-card__inner,
  .fx-card.is-demo .fx-card__inner { animation: none !important; transition: none !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: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.fx-card {
  perspective: 700px;
  width: 132px;
  height: 132px;
  border: 0;
  padding: 0;
  background: none;
  cursor: pointer;
  display: block;
}

.fx-card:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 4px;
}

.fx-card__inner {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.fx-card.is-flipped .fx-card__inner {
  transform: rotateX(180deg);
}

.fx-card__face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  backface-visibility: hidden;
  font: 700 34px/1 -apple-system, "Segoe UI", sans-serif;
  color: #fff7e6;
}

.fx-card__face--front {
  background: #17141a;
}

.fx-card__face--back {
  background: rgba(23, 20, 26, 0.8);
  transform: rotateX(180deg);
}

@keyframes fx-flip {
  0%, 40% {
    transform: rotateX(0);
  }
  60%, 100% {
    transform: rotateX(180deg);
  }
}
.fx-card.is-demo .fx-card__inner {
  animation: fx-flip 1200ms cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@media (prefers-reduced-motion: reduce) {
  .fx-card.is-flipped .fx-card__inner,
  .fx-card.is-demo .fx-card__inner {
    animation: none !important;
    transition: none !important;
    transform: none !important;
  }
}

var btn = document.querySelector(".fx-card");
  btn.addEventListener("click", function () {
    var open = btn.getAttribute("aria-pressed") === "true";
    btn.setAttribute("aria-pressed", String(!open));
    btn.classList.toggle("is-flipped", !open);
  });

import { CSSProperties, useState } from "react";
import styles from "./FlipXClick.module.scss";

export interface FlipXClickProps {
  duration?: string;
  easing?: string;
  front?: string;
  back?: string;
}

export default function FlipXClick({
  duration = "600ms",
  easing = "cubic-bezier(.2, .8, .2, 1)",
  front = "Q",
  back = "A",
}: FlipXClickProps) {
  const [open, setOpen] = useState(false);
  const style = { "--duration": duration, "--easing": easing } as CSSProperties;
  return (
    <button
      type="button"
      className={`${styles.card} ${open ? styles.flipped : ""}`}
      style={style}
      aria-pressed={open}
      onClick={() => setOpen((v) => !v)}
    >
      <span className={styles.inner}>
        <span className={`${styles.face} ${styles.front}`}>{front}</span>
        <span className={`${styles.face} ${styles.back}`}>{back}</span>
      </span>
    </button>
  );
}