033-item stack

<main class="stage">
  <div class="stack is-demo" tabindex="0" role="status" aria-live="polite" aria-label="3 notifications">
    <div class="stack__item" style="--i:2">Points earned</div>
    <div class="stack__item" style="--i:1">Shipment started</div>
    <div class="stack__item" style="--i:0">Payment completed</div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────
$duration: $dur-base;    // 300ms — 실제 hover/focus 로 펼쳐지는 속도
$easing: $ease-spring;
$color: $subject-cream;  // 카드 색

// ── 데모 무대 ───────────────────────────────
@include stage($stage-orange);

.stack {
  position: relative;
  width: min(260px, 78vw);
  height: 92px;
  outline: none;
}
.stack__item {
  position: absolute; inset: 0;
  display: flex; align-items: center;
  padding: $sp-4;
  border-radius: $r-card;
  background: $color;
  color: $subject-ink;
  font-weight: 600;
  font-size: 13px;
  line-height: 1.4;
  font-family: inherit;
  box-shadow: $shadow-press;
  // 뒤 카드일수록(--i 클수록) 더 밀리고 작아지고 흐려진다 — 평소엔 살짝 겹친 "덱" 모양
  transform: translateY(calc(var(--i) * -6px)) scale(calc(1 - var(--i) * .05));
  opacity: calc(1 - var(--i) * .22);
}

// 실제 사용: hover·focus 로 카드 3장을 부채꼴로 펼친다 (JS 없이)
.stack:hover .stack__item,
.stack:focus-within .stack__item {
  transform: translateY(calc(var(--i) * -22px)) scale(1);
  opacity: 1;
  transition: transform $duration $easing, opacity $duration $easing;
}

// 실측 2026-09-10: 018 편의 "토스트 쌓임"(새 토스트가 올수록 기존 걸 밀어 올리는 큐)과 다르다 —
// 여기는 항상 3장이 고정으로 있고, 접힌 덱이 펼쳐졌다 다시 접히는 "카드 뭉치" 자체가 하나의 애니메이션이다.
.stack.is-demo .stack__item { animation: spread $dur-loop $easing infinite; }

@keyframes spread {
  0%, 100% {
    transform: translateY(calc(var(--i) * -6px)) scale(calc(1 - var(--i) * .05));
    opacity: calc(1 - var(--i) * .22);
  }
  35%, 65% {
    transform: translateY(calc(var(--i) * -22px)) scale(1);
    opacity: 1;
  }
}

// ── 접근성: 움직임 줄이기 설정이면 펼쳐진 채로 고정 ────────
@media (prefers-reduced-motion: reduce) {
  .stack.is-demo .stack__item { animation: none; transform: translateY(calc(var(--i) * -22px)) scale(1); opacity: 1; }
}

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);
}

.stack {
  position: relative;
  width: min(260px, 78vw);
  height: 92px;
  outline: none;
}

.stack__item {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  padding: 16px;
  border-radius: 16px;
  background: #fff7e6;
  color: #17141a;
  font-weight: 600;
  font-size: 13px;
  line-height: 1.4;
  font-family: inherit;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transform: translateY(calc(var(--i) * -6px)) scale(calc(1 - var(--i) * 0.05));
  opacity: calc(1 - var(--i) * 0.22);
}

.stack:hover .stack__item,
.stack:focus-within .stack__item {
  transform: translateY(calc(var(--i) * -22px)) scale(1);
  opacity: 1;
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1), opacity 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.stack.is-demo .stack__item {
  animation: spread 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes spread {
  0%, 100% {
    transform: translateY(calc(var(--i) * -6px)) scale(calc(1 - var(--i) * 0.05));
    opacity: calc(1 - var(--i) * 0.22);
  }
  35%, 65% {
    transform: translateY(calc(var(--i) * -22px)) scale(1);
    opacity: 1;
  }
}
@media (prefers-reduced-motion: reduce) {
  .stack.is-demo .stack__item {
    animation: none;
    transform: translateY(calc(var(--i) * -22px)) scale(1);
    opacity: 1;
  }
}

import type { CSSProperties } from "react";
import styles from "./ToastStack3.module.scss";

export type ToastStack3Props = {
  /** 앞(맨 위)부터 순서대로 3개 */
  items: [string, string, string];
  color?: string;
  duration?: number;
  easing?: string;
};

type ItemVars = CSSProperties & { "--i"?: number };

export default function ToastStack3({
  items,
  color = "#fff7e6",
  duration = 300,
  easing = "cubic-bezier(.2,.8,.2,1)",
}: ToastStack3Props) {
  const vars = { "--color": color, "--duration": `${duration}ms`, "--easing": easing } as CSSProperties;
  const withIndex = items.map((text, i) => ({ text, i }));
  const backToFront = [...withIndex].reverse(); // DOM은 뒤(i 큰 값)부터 써야 앞(i=0)이 맨 위에 그려진다

  return (
    <div
      className={styles.stack}
      style={vars}
      tabIndex={0}
      role="status"
      aria-live="polite"
      aria-label={`알림 ${items.length}개`}
    >
      {backToFront.map(({ text, i }) => {
        const itemVars: ItemVars = { "--i": i };
        return (
          <div key={i} className={styles.item} style={itemVars}>
            {text}
          </div>
        );
      })}
    </div>
  );
}