08:has(:checked) 축하 트리거

<main class="stage">
  <label class="hc-wrap is-demo">
    <input class="hc-check" type="checkbox">
    <span class="hc-box" aria-hidden="true"></span>
    <span class="hc-text">할 일 완료</span>
    <span class="hc-piece"></span><span class="hc-piece"></span><span class="hc-piece"></span>
    <span class="hc-piece"></span><span class="hc-piece"></span><span class="hc-piece"></span>
    <span class="hc-piece"></span><span class="hc-piece"></span>
  </label>
</main>

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

// ── 변수 3개 ──────────────────────────────────────────
$duration: 800ms;
$easing: $ease-pop;
$color: $subject-blue;

@include stage($stage-paper);

$piece-colors: $color, $stage-orange, $stage-yellow;

.hc-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-3 $sp-5;
  border-radius: $r-control;
  background: $subject-ink;
  color: $subject-cream;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
}

.hc-check { position: absolute; width: 1px; height: 1px; opacity: 0; }

.hc-box {
  width: 18px;
  height: 18px;
  border-radius: $r-xs;
  border: 2px solid $subject-cream;
  box-sizing: border-box;
  transition: background $dur-quick, border-color $dur-quick;
}

// JS 없이: 부모가 :has(:checked) 로 체크 상태를 읽어 박스와 컨페티를 함께 켠다
.hc-wrap:has(.hc-check:checked) .hc-box { background: $color; border-color: $color; }

.hc-piece {
  position: absolute;
  top: 50%;
  left: 24px;
  width: 8px;
  height: 8px;
  border-radius: $r-xs;
  opacity: 0;
  pointer-events: none;
}

@for $i from 1 through 8 {
  .hc-piece:nth-child(#{$i + 3}) {
    background: nth($piece-colors, ($i - 1) % 3 + 1);
    --angle: #{$i * 45deg};
  }
}

@keyframes hc-fly {
  0%   { transform: translate(-50%, -50%) rotate(var(--angle)) translateY(0) scale(.4); opacity: 0; }
  20%  { opacity: 1; }
  100% { transform: translate(-50%, -50%) rotate(var(--angle)) translateY(-58px) scale(1); opacity: 0; }
}

.hc-wrap:has(.hc-check:checked) .hc-piece,
.hc-wrap.is-demo .hc-piece { animation: hc-fly $duration $easing infinite; }

@media (prefers-reduced-motion: reduce) {
  .hc-wrap:has(.hc-check:checked) .hc-piece,
  .hc-wrap.is-demo .hc-piece { animation: none !important; opacity: 0 !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);
}

.hc-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 12px;
  background: #17141a;
  color: #fff7e6;
  font: 700 14px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
}

.hc-check {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.hc-box {
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 2px solid #fff7e6;
  box-sizing: border-box;
  transition: background 220ms, border-color 220ms;
}

.hc-wrap:has(.hc-check:checked) .hc-box {
  background: #2f6df6;
  border-color: #2f6df6;
}

.hc-piece {
  position: absolute;
  top: 50%;
  left: 24px;
  width: 8px;
  height: 8px;
  border-radius: 4px;
  opacity: 0;
  pointer-events: none;
}

.hc-piece:nth-child(4) {
  background: #2f6df6;
  --angle: 45deg;
}

.hc-piece:nth-child(5) {
  background: #ff4d1f;
  --angle: 90deg;
}

.hc-piece:nth-child(6) {
  background: #ffd23f;
  --angle: 135deg;
}

.hc-piece:nth-child(7) {
  background: #2f6df6;
  --angle: 180deg;
}

.hc-piece:nth-child(8) {
  background: #ff4d1f;
  --angle: 225deg;
}

.hc-piece:nth-child(9) {
  background: #ffd23f;
  --angle: 270deg;
}

.hc-piece:nth-child(10) {
  background: #2f6df6;
  --angle: 315deg;
}

.hc-piece:nth-child(11) {
  background: #ff4d1f;
  --angle: 360deg;
}

@keyframes hc-fly {
  0% {
    transform: translate(-50%, -50%) rotate(var(--angle)) translateY(0) scale(0.4);
    opacity: 0;
  }
  20% {
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) rotate(var(--angle)) translateY(-58px) scale(1);
    opacity: 0;
  }
}
.hc-wrap:has(.hc-check:checked) .hc-piece,
.hc-wrap.is-demo .hc-piece {
  animation: hc-fly 800ms cubic-bezier(0.2, 1.4, 0.4, 1) infinite;
}

@media (prefers-reduced-motion: reduce) {
  .hc-wrap:has(.hc-check:checked) .hc-piece,
  .hc-wrap.is-demo .hc-piece {
    animation: none !important;
    opacity: 0 !important;
  }
}

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

type Vars = CSSProperties & Record<string, string>;

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

const COLORS = ["var(--color)", "#ff4d1f", "#ffd23f"];

// JS 없이: 부모 label 이 :has(input:checked) 로 상태를 읽어 체크박스와 컨페티를 함께 켠다
export default function HasCheckedCelebrate({
  duration = "800ms",
  easing = "cubic-bezier(.2, 1.4, .4, 1)",
  color = "#2f6df6",
}: HasCheckedCelebrateProps) {
  const style: Vars = { "--duration": duration, "--easing": easing, "--color": color };
  return (
    <label className={styles.wrap} style={style}>
      <input className={styles.check} type="checkbox" />
      <span className={styles.box} aria-hidden="true" />
      <span className={styles.text}>할 일 완료</span>
      {Array.from({ length: 8 }, (_, i) => {
        const pieceStyle: Vars = {
          background: COLORS[i % COLORS.length],
          "--angle": `${(i + 1) * 45}deg`,
        };
        return <span key={i} className={styles.piece} style={pieceStyle} />;
      })}
    </label>
  );
}