02Bounce

<main class="stage">
  <div class="hint a-bounce">
    <span class="hint__arrow" aria-hidden="true"></span>
    See more
  </div>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 1s;
$easing: cubic-bezier(.28, .84, .42, 1);   // 떨어질 때 빠르고 튀어 오를 때 감속 — 중력을 흉내낸다
$color: $stage-ink;

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

.hint {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: $color;
  font-weight: 700; font-size: clamp(14px, 4vw, 17px); line-height: 1; font-family: inherit;
}
.hint__arrow {
  width: 14px;
  height: 14px;
  border-right: 3px solid $color;
  border-bottom: 3px solid $color;
  transform: rotate(45deg);
}

// ── .a-bounce 하나로 바닥에 튕기는 리듬을 만든다 ──────────
.a-bounce {
  animation: bounce $duration $easing infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  30%      { transform: translateY(-4px); }
  55%      { transform: translateY(10px); }
  75%      { transform: translateY(-2px); }
  90%      { transform: translateY(4px); }
}

@media (prefers-reduced-motion: reduce) {
  .a-bounce { animation: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.hint {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: #17141a;
  font-weight: 700;
  font-size: clamp(14px, 4vw, 17px);
  line-height: 1;
  font-family: inherit;
}

.hint__arrow {
  width: 14px;
  height: 14px;
  border-right: 3px solid #17141a;
  border-bottom: 3px solid #17141a;
  transform: rotate(45deg);
}

.a-bounce {
  animation: bounce 1s cubic-bezier(0.28, 0.84, 0.42, 1) infinite;
}

@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
  }
  30% {
    transform: translateY(-4px);
  }
  55% {
    transform: translateY(10px);
  }
  75% {
    transform: translateY(-2px);
  }
  90% {
    transform: translateY(4px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .a-bounce {
    animation: none;
  }
}

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

export type BounceHintProps = {
  children: ReactNode;
  /** 한 번 튀는 데 걸리는 시간 (기본 1000ms) */
  duration?: number;
  /** CSS easing (기본 중력을 흉내낸 커스텀 베지어) */
  easing?: string;
  /** 화살표·글자 색 */
  color?: string;
};

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

export default function BounceHint({
  children,
  duration = 1000,
  easing = "cubic-bezier(.28,.84,.42,1)",
  color = "#17141a",
}: BounceHintProps) {
  const vars: Vars = {
    "--duration": `${duration}ms`,
    "--easing": easing,
    "--color": color,
  };
  return (
    <div className={styles.hint} style={vars}>
      <span className={styles.arrow} aria-hidden="true" />
      {children}
    </div>
  );
}