07重ね持ち上げ切替 — 詳細値がオンになると後ろに重なっていた同じ形の値が上へ順に持ち上がる方式

<main class="stage">
<div class="sl is-demo" id="sl">
  <div class="sl__pile" id="slPile">
    <div class="sl__ghost" style="--n: 3"></div>
    <div class="sl__ghost" style="--n: 2"></div>
    <div class="sl__ghost" style="--n: 1"></div>
    <div class="sl__card">
      <span class="sl__title">通知値のまとまり</span>
      <span class="sl__sub">後ろに値3つ重なり</span>
    </div>
  </div>
  <button type="button" class="sl__btn" id="slBtn" aria-expanded="false">
    <span class="sl__label">詳細値を開く</span>
  </button>
</div>
</main>

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

// 계산 겹: 겹친 카드의 y 오프셋이 --n(뒤에서부터의 차례) * STEP_PX(34px) 산술로 결정되고,
// 들림은 $ease-lerp-settle 표본곡선(오버슈트 후 빠른 정착)으로 스프링 감쇠를 흉내낸다.
@include stage($stage-orange);

.sl {
  display: grid;
  gap: $sp-5;
  justify-items: center;
}

.sl__pile {
  position: relative;
  width: 230px;
  height: 118px;
}

.sl__ghost {
  position: absolute;
  inset: 0;
  border-radius: $r-card;
  background: rgba($stage-paper, .35);
  border: 1px solid rgba($stage-paper, .5);
  transform: translateY(calc((4 - var(--n)) * 4px));
  transition: transform $dur-enter $ease-lerp-settle;
}

.sl__card {
  position: absolute;
  inset: 0;
  border-radius: $r-card;
  background: $stage-paper;
  box-shadow: $shadow-raised;
  display: grid;
  align-content: center;
  gap: $sp-1;
  padding: 0 $sp-5;
  box-sizing: border-box;
}

.sl__title {
  color: $subject-ink;
  font-weight: 700;
  font-size: 15px;
}

.sl__sub {
  color: $subject-orange-deep;
  font-weight: 600;
  font-size: 12px;
}

.sl__btn {
  border: 0;
  border-radius: $r-pill;
  background: $stage-paper;
  color: $subject-ink;
  padding: $sp-2 $sp-5;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
}

.sl--open {
  .sl__ghost {
    transform: translateY(calc(-1 * var(--n) * 34px)) scale(calc(1 - var(--n) * .03));
  }
}

@media (max-width: 340px) {
  .sl__pile { width: 200px; height: 108px; }
}

@media (prefers-reduced-motion: reduce) {
  .sl__ghost { transition: 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);
}

.sl {
  display: grid;
  gap: 20px;
  justify-items: center;
}

.sl__pile {
  position: relative;
  width: 230px;
  height: 118px;
}

.sl__ghost {
  position: absolute;
  inset: 0;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.5);
  transform: translateY(calc((4 - var(--n)) * 4px));
  transition: transform 600ms linear(0, 0.051, 0.176, 0.341, 0.518, 0.685, 0.831, 0.947, 1.032, 1.087, 1.117, 1.126, 1.121, 1.105, 1.085, 1.062, 1.041, 1.022, 1.008, 0.997, 1);
}

.sl__card {
  position: absolute;
  inset: 0;
  border-radius: 16px;
  background: #ffffff;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  display: grid;
  align-content: center;
  gap: 4px;
  padding: 0 20px;
  box-sizing: border-box;
}

.sl__title {
  color: #17141a;
  font-weight: 700;
  font-size: 15px;
}

.sl__sub {
  color: #c93000;
  font-weight: 600;
  font-size: 12px;
}

.sl__btn {
  border: 0;
  border-radius: 999px;
  background: #ffffff;
  color: #17141a;
  padding: 8px 20px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
}

.sl--open .sl__ghost {
  transform: translateY(calc(-1 * var(--n) * 34px)) scale(calc(1 - var(--n) * 0.03));
}

@media (max-width: 340px) {
  .sl__pile {
    width: 200px;
    height: 108px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sl__ghost {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('sl');
  var btn = document.getElementById('slBtn');
  var ghosts = root.querySelectorAll('.sl__ghost');
  var sub = root.querySelector('.sl__sub');
  var STEP_PX = 34; // 계산 겹: 겹침 카드 하나가 위로 들리는 y 오프셋(px) — 스프링 감쇠로 산출
  var STAGGER_MS = 80; // 계산 겹: 뒤 카드부터 이 값씩 늦게 들린다

  ghosts.forEach(function (g, i) {
    g.style.transitionDelay = ((ghosts.length - 1 - i) * STAGGER_MS) + 'ms';
  });

  var open = false;
  function paint() {
    root.classList.toggle('sl--open', open);
    btn.setAttribute('aria-expanded', String(open));
    sub.textContent = open ? '値3つ展開' : '後ろに値3つ重なり';
  }

  function toggle() {
    open = !open;
    paint();
  }

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    stopAutoplay();
    toggle();
  });

  var autoTimer = null;
  function stopAutoplay() { if (autoTimer) { clearInterval(autoTimer); autoTimer = null; } }
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (!reduce) { autoTimer = setInterval(toggle, 1400); }
  else { open = true; paint(); }
})();

import { useEffect, useRef } from "react";
import type { CSSProperties } from "react";
import styles from "./StackCardLift.module.scss";

type Box<T> = { current: T };

const STEP_PX = 34; // 계산 겹: 겹침 카드 하나가 위로 들리는 y 오프셋(px) — 스프링 감쇠로 산출
const STAGGER_MS = 80; // 계산 겹: 뒤 카드부터 이 값씩 늦게 들린다

export default function StackCardLift() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLButtonElement | null;
    const ghosts = root.querySelectorAll(`.${styles.ghost}`);
    const sub = root.querySelector(`.${styles.sub}`) as HTMLElement | null;
    if (!btn) return;

    ghosts.forEach((g, i) => {
      (g as HTMLElement).style.transitionDelay = ((ghosts.length - 1 - i) * STAGGER_MS) + "ms";
    });

    let open = false;
    function paint() {
      root!.classList.toggle(styles["root--open"], open);
      btn!.setAttribute("aria-expanded", String(open));
      if (sub) sub.textContent = open ? "값 3개 펼침" : "뒤에 값 3개 겹침";
    }
    function toggle() {
      open = !open;
      paint();
    }

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      stopAutoplay();
      toggle();
    }
    btn.addEventListener("click", onClick);

    let autoTimer: number | null = null;
    function stopAutoplay() { if (autoTimer !== null) { window.clearInterval(autoTimer); autoTimer = null; } }
    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    if (!reduce) { autoTimer = window.setInterval(toggle, 1400); }
    else { open = true; paint(); }

    return () => {
      stopAutoplay();
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.sl} ${styles["is-demo"]}`}>
      <div className={styles.pile}>
        <div className={styles.ghost} style={{ "--n": 3 } as CSSProperties} />
        <div className={styles.ghost} style={{ "--n": 2 } as CSSProperties} />
        <div className={styles.ghost} style={{ "--n": 1 } as CSSProperties} />
        <div className={styles.card}>
          <span className={styles.title}>알림 값 묶음</span>
          <span className={styles.sub}>뒤에 값 3개 겹침</span>
        </div>
      </div>
      <button type="button" className={styles.btn} aria-expanded="false">
        <span className={styles.label}>자세히 값 열기</span>
      </button>
    </div>
  );
}