04쿵 찍는 공

<main class="stage">
  <div class="sq-scene is-demo" aria-hidden="true">
    <div class="sq-ball"></div>
    <div class="sq-shadow"></div>
    <div class="sq-floor"></div>
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 1s;
$easing: cubic-bezier(.45, 0, .8, .6);   // 떨어질 때: 점점 빨라지는 중력
$color: $subject-blue;

@include stage($stage-paper);

// 실사용: 로딩 중에만 .is-loading
.sq-scene {
  position: relative;
  width: 112px;
  height: 164px;
}

.sq-ball {
  position: absolute;
  left: 50%;
  bottom: 2px;   // 바닥선(2px) 위에 정확히 얹힌다
  width: 56px;
  height: 56px;
  margin-left: -28px;
  border-radius: 50%;
  background: $color;
  transform-origin: 50% 100%;   // 바닥에 닿은 채로 찍히게
}

.sq-shadow {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 56px;
  height: $sp-1;
  margin-left: -28px;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .22);
}

.sq-floor {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: $subject-ink;
}

.sq-scene.is-loading .sq-ball,
.sq-scene.is-demo .sq-ball {
  animation: sq-bounce $duration $easing infinite;
}
.sq-scene.is-loading .sq-shadow,
.sq-scene.is-demo .sq-shadow {
  animation: sq-shadow-pulse $duration $easing infinite;
}

@keyframes sq-bounce {
  0%   { transform: translateY(-98px) scale(1, 1); }
  55%  { transform: translateY(0) scale(1, 1); }       // 바닥 도착
  68%  { transform: translateY(0) scale(1.28, .55); }  // 쿵 — 찍힘
  80%  { transform: translateY(0) scale(.92, 1.08); }  // 되튕기며 복원
  100% { transform: translateY(-98px) scale(1, 1); }
}

@keyframes sq-shadow-pulse {
  0%, 100% { transform: scale(.5); opacity: .3; }
  55%, 80% { transform: scale(1.05); opacity: .75; }
}

@media (prefers-reduced-motion: reduce) {
  .sq-scene.is-loading .sq-ball,
  .sq-scene.is-demo .sq-ball {
    animation: none !important;
    transform: translateY(-40px) !important;   // 정지해도 공중에 떠 있는 모양
  }
  .sq-scene.is-loading .sq-shadow,
  .sq-scene.is-demo .sq-shadow {
    animation: none !important;
    opacity: .5 !important;
    transform: scale(.8) !important;
  }
}

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

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

.sq-scene {
  position: relative;
  width: 112px;
  height: 164px;
}

.sq-ball {
  position: absolute;
  left: 50%;
  bottom: 2px;
  width: 56px;
  height: 56px;
  margin-left: -28px;
  border-radius: 50%;
  background: #2f6df6;
  transform-origin: 50% 100%;
}

.sq-shadow {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 56px;
  height: 4px;
  margin-left: -28px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.22);
}

.sq-floor {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: #17141a;
}

.sq-scene.is-loading .sq-ball,
.sq-scene.is-demo .sq-ball {
  animation: sq-bounce 1s cubic-bezier(0.45, 0, 0.8, 0.6) infinite;
}

.sq-scene.is-loading .sq-shadow,
.sq-scene.is-demo .sq-shadow {
  animation: sq-shadow-pulse 1s cubic-bezier(0.45, 0, 0.8, 0.6) infinite;
}

@keyframes sq-bounce {
  0% {
    transform: translateY(-98px) scale(1, 1);
  }
  55% {
    transform: translateY(0) scale(1, 1);
  }
  68% {
    transform: translateY(0) scale(1.28, 0.55);
  }
  80% {
    transform: translateY(0) scale(0.92, 1.08);
  }
  100% {
    transform: translateY(-98px) scale(1, 1);
  }
}
@keyframes sq-shadow-pulse {
  0%, 100% {
    transform: scale(0.5);
    opacity: 0.3;
  }
  55%, 80% {
    transform: scale(1.05);
    opacity: 0.75;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sq-scene.is-loading .sq-ball,
  .sq-scene.is-demo .sq-ball {
    animation: none !important;
    transform: translateY(-40px) !important;
  }
  .sq-scene.is-loading .sq-shadow,
  .sq-scene.is-demo .sq-shadow {
    animation: none !important;
    opacity: 0.5 !important;
    transform: scale(0.8) !important;
  }
}

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

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

export interface SquishBallProps {
  duration?: string;
  easing?: string;
  color?: string;
}

export default function SquishBall({
  duration = "1s",
  easing = "cubic-bezier(.45, 0, .8, .6)",
  color = "#2f6df6",
}: SquishBallProps) {
  const style: Vars = {
    "--duration": duration,
    "--easing": easing,
    "--color": color,
  };
  return (
    <div className={styles.scene} style={style} aria-hidden="true">
      <div className={styles.ball} />
      <div className={styles.shadow} />
      <div className={styles.floor} />
    </div>
  );
}