05Empty cart that rolls in

<main class="stage">
  <section class="ct is-demo" aria-labelledby="ct-t">
    <div class="ct__track">
      <span class="ct__cart" aria-hidden="true"><svg viewBox="0 0 256 256" width="1em" height="1em"><g fill="currentColor"><path d="m232 72l-25.63 92.28A16 16 0 0 1 191 176H92.16a16 16 0 0 1-15.41-11.72L51.11 72Z" opacity=".2"/><path d="M104 216a16 16 0 1 1-16-16a16 16 0 0 1 16 16m88-16a16 16 0 1 0 16 16a16 16 0 0 0-16-16m47.71-125.86l-25.64 92.28A24.06 24.06 0 0 1 191 184H92.16A24.06 24.06 0 0 1 69 166.42L33.92 40H16a8 8 0 0 1 0-16h24a8 8 0 0 1 7.71 5.86L57.19 64H232a8 8 0 0 1 7.71 10.14M221.47 80H61.64l22.81 82.14a8 8 0 0 0 7.71 5.86H191a8 8 0 0 0 7.71-5.86Z"/></g></svg></span>
    </div>
    <h2 class="ct__title" id="ct-t">Your cart is empty</h2>
    <p class="ct__sub" id="ct-s" data-fmt="{n} items · {won} KRW" aria-live="polite">0 items · 0 KRW</p>
    <button class="ct__btn" type="button" id="ct-b" data-more="Add one more">Keep shopping</button>
  </section>
</main>

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

$duration: $dur-loop;
$easing: $ease-spring;
$color: $subject-cream;

@include stage($stage-ink);

.ct {
  box-sizing: border-box;
  width: min(248px, 86vw);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-2;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
  color: $color;
}

.ct__track {
  box-sizing: border-box;
  width: 100%;
  height: 64px;
  display: grid;
  place-items: center;
  border-bottom: 1px dashed rgba(255, 247, 230, .28);
  overflow: hidden;
}
.ct__cart {
  display: block;
  font-size: clamp(36px, 11vw, 48px);
  line-height: 0;
  color: $color;
  transform-origin: 50% 78%; // 규칙8: 수레 바퀴점 피벗
}

.ct__title {
  margin: 0;
  font-size: clamp(12px, 4vw, 14px);
  line-height: 1.3;
  font-weight: 800;
}
.ct__sub {
  margin: 0;
  min-height: 14px;
  font-size: 11px;
  line-height: 14px;
  font-weight: 600;
  color: rgba(255, 247, 230, .62);
}
.ct.is-filled .ct__sub { color: $color; }
.ct__btn {
  height: 28px;
  margin: 0;
  padding: 0 $sp-4;
  border: 0;
  border-radius: $r-pill;
  background: $subject-blue-deep;
  color: $color;
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
}
.ct__btn:focus-visible { outline: 2px solid $color; outline-offset: 2px; }

// ── 자동 루프: 왼쪽에서 굴러 들어와 한 번 기울었다가 같은 길로 굴러 나간다. 0% 와 100% 가 같은 자리 ──
.ct.is-demo .ct__cart { animation: ct-roll $duration $easing infinite; }
@keyframes ct-roll {
  0%, 100% { transform: translateX(-74px) rotate(-14deg); }
  38%      { transform: translateX(0) rotate(0deg); }
  52%      { transform: translateX(0) rotate(-9deg); }
  66%      { transform: translateX(0) rotate(0deg); }
}

@media (prefers-reduced-motion: reduce) {
  .ct.is-demo .ct__cart { animation: none !important; transform: translateX(0); }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.ct {
  box-sizing: border-box;
  width: min(248px, 86vw);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  text-align: center;
  color: #fff7e6;
}

.ct__track {
  box-sizing: border-box;
  width: 100%;
  height: 64px;
  display: grid;
  place-items: center;
  border-bottom: 1px dashed rgba(255, 247, 230, 0.28);
  overflow: hidden;
}

.ct__cart {
  display: block;
  font-size: clamp(36px, 11vw, 48px);
  line-height: 0;
  color: #fff7e6;
  transform-origin: 50% 78%;
}

.ct__title {
  margin: 0;
  font-size: clamp(12px, 4vw, 14px);
  line-height: 1.3;
  font-weight: 800;
}

.ct__sub {
  margin: 0;
  min-height: 14px;
  font-size: 11px;
  line-height: 14px;
  font-weight: 600;
  color: rgba(255, 247, 230, 0.62);
}

.ct.is-filled .ct__sub {
  color: #fff7e6;
}

.ct__btn {
  height: 28px;
  margin: 0;
  padding: 0 16px;
  border: 0;
  border-radius: 999px;
  background: #0a4fe8;
  color: #fff7e6;
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  cursor: pointer;
}

.ct__btn:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 2px;
}

.ct.is-demo .ct__cart {
  animation: ct-roll 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes ct-roll {
  0%, 100% {
    transform: translateX(-74px) rotate(-14deg);
  }
  38% {
    transform: translateX(0) rotate(0deg);
  }
  52% {
    transform: translateX(0) rotate(-9deg);
  }
  66% {
    transform: translateX(0) rotate(0deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .ct.is-demo .ct__cart {
    animation: none !important;
    transform: translateX(0);
  }
}

// 실제 동작: 버튼을 누를 때마다 상품 하나가 실제로 담기고 합계가 다시 계산된다.
var card = document.querySelector('.ct');
var btn = document.getElementById('ct-b');
var sub = document.getElementById('ct-s');
var items = 0;
btn.addEventListener('click', function () {
  card.classList.remove('is-demo');
  items += 1;
  card.classList.toggle('is-filled', items > 0);
  sub.textContent = sub.dataset.fmt.replace('{n}', items).replace('{won}', (items * 12000).toLocaleString());
  btn.textContent = btn.dataset.more;
});

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

export type EmptyCartCardProps = {
  title?: string;
  fmt?: string;
  action?: string;
  more?: string;
  unitPrice?: number;
  duration?: number;
  easing?: string;
  color?: string;
};

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

export default function EmptyCartCard({
  title = "Your cart is empty",
  fmt = "{n} items · {won} KRW",
  action = "Keep shopping",
  more = "Add one more",
  unitPrice = 12000,
  duration = 2000,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#fff7e6",
}: EmptyCartCardProps) {
  const [items, setItems] = useState(0);
  const [loop, setLoop] = useState(true);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  const sub = fmt.replace("{n}", String(items)).replace("{won}", (items * unitPrice).toLocaleString());
  const cls = [styles.ct, loop ? styles.isDemo : "", items > 0 ? styles.isFilled : ""].join(" ");

  return (
    <section className={cls} style={vars}>
      <div className={styles.track}>
        <span className={styles.cart} aria-hidden="true">
          <svg viewBox="0 0 256 256" width="1em" height="1em">
            <g fill="currentColor">
              <path d="m232 72l-25.63 92.28A16 16 0 0 1 191 176H92.16a16 16 0 0 1-15.41-11.72L51.11 72Z" opacity=".2" />
              <path d="M104 216a16 16 0 1 1-16-16a16 16 0 0 1 16 16m88-16a16 16 0 1 0 16 16a16 16 0 0 0-16-16m47.71-125.86l-25.64 92.28A24.06 24.06 0 0 1 191 184H92.16A24.06 24.06 0 0 1 69 166.42L33.92 40H16a8 8 0 0 1 0-16h24a8 8 0 0 1 7.71 5.86L57.19 64H232a8 8 0 0 1 7.71 10.14M221.47 80H61.64l22.81 82.14a8 8 0 0 0 7.71 5.86H191a8 8 0 0 0 7.71-5.86Z" />
            </g>
          </svg>
        </span>
      </div>
      <h2 className={styles.title}>{title}</h2>
      <p className={styles.sub} aria-live="polite">{sub}</p>
      <button
        className={styles.btn}
        type="button"
        onClick={() => { setLoop(false); setItems(items + 1); }}
      >
        {items > 0 ? more : action}
      </button>
    </section>
  );
}