02浮き上がり

<main class="stage"><button class="btn is-demo" type="button">カートに入れる</button></main>

// ── 변수 3개 ──────────────────────────────────────────
$lift: 6px;                                      // 얼마나 뜨나
$duration: 220ms;
$shadow: rgba(23, 20, 26, .32);                  // 그림자 색. 없애려면 transparent

html, body { margin: 0; overflow: hidden; }          // iframe 안에서 스크롤바가 생기지 않게 (실측 2026-09-09: body 여백 8px 이 100vh 를 넘겼다)
.stage { min-height: 100vh; display: grid; place-items: center; margin: 0; background: #d2c7a4; font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif; }

.btn {
  border: 0;
  border-radius: 14px;
  padding: 22px 56px;
  font-weight: 800;
  font-size: 20px;
  line-height: 1;
  font-family: inherit;
  color: #fff7e6;
  background: #17141a;
  cursor: pointer;
  will-change: transform;
  transition: transform $duration cubic-bezier(.2, .8, .2, 1), box-shadow $duration;

  &:hover, &:focus-visible { transform: translateY(-$lift); box-shadow: 0 14px 24px $shadow; }
  &:active { transform: translateY(-2px); box-shadow: 0 6px 12px $shadow; }

  // 데모 · 문서용 자동 반복
  &.is-demo { animation: lift-loop 2s ease-in-out infinite; }
}

@keyframes lift-loop {
  0%, 15%   { transform: translateY(0);      box-shadow: 0 0 0 rgba(23, 20, 26, 0); }
  45%, 70%  { transform: translateY(-$lift); box-shadow: 0 14px 24px $shadow; }
  100%      { transform: translateY(0);      box-shadow: 0 0 0 rgba(23, 20, 26, 0); }
}

@media (prefers-reduced-motion: reduce) {
  .btn, .btn.is-demo { transition: none; animation: none; }
  .btn:hover { box-shadow: 0 14px 24px $shadow; }   // 뜨지 않고 그림자만
}

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

.stage {
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #d2c7a4;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.btn {
  border: 0;
  border-radius: 14px;
  padding: 22px 56px;
  font-weight: 800;
  font-size: 20px;
  line-height: 1;
  font-family: inherit;
  color: #fff7e6;
  background: #17141a;
  cursor: pointer;
  will-change: transform;
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms;
}
.btn:hover, .btn:focus-visible {
  transform: translateY(-6px);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}
.btn:active {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}
.btn.is-demo {
  animation: lift-loop 2s ease-in-out infinite;
}

@keyframes lift-loop {
  0%, 15% {
    transform: translateY(0);
    box-shadow: 0 0 0 rgba(23, 20, 26, 0);
  }
  45%, 70% {
    transform: translateY(-6px);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
  100% {
    transform: translateY(0);
    box-shadow: 0 0 0 rgba(23, 20, 26, 0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn, .btn.is-demo {
    transition: none;
    animation: none;
  }
  .btn:hover {
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
}

// 데모(.is-demo)는 자동 반복. 사람이 올리면 진짜 호버로 넘어간다.
document.querySelectorAll('.btn').forEach(function (b) {
  b.addEventListener('pointerenter', function () { b.classList.remove('is-demo'); });
});

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

export type LiftButtonProps = { children: ReactNode; lift?: number; duration?: number; shadow?: string; onClick?: () => void };

export default function LiftButton({ children, lift = 6, duration = 220, shadow = "rgba(23,20,26,.32)", onClick }: LiftButtonProps) {
  const vars = { "--lift": `${lift}px`, "--duration": `${duration}ms`, "--shadow": shadow } as CSSProperties;
  return (
    <button type="button" className={styles.btn} style={vars} onClick={onClick}>
      {children}
    </button>
  );
}