07蛍

<main class="stage">
  <div class="field" aria-hidden="true">
    <span class="p" style="--i:0"></span>
    <span class="p" style="--i:1"></span>
    <span class="p" style="--i:2"></span>
    <span class="p" style="--i:3"></span>
    <span class="p" style="--i:4"></span>
    <span class="p" style="--i:5"></span>
    <span class="p" style="--i:6"></span>
    <span class="p" style="--i:7"></span>
    <span class="p" style="--i:8"></span>
    <span class="p" style="--i:9"></span>
    <span class="p" style="--i:10"></span>
    <span class="p" style="--i:11"></span>
    <span class="p" style="--i:12"></span>
    <span class="p" style="--i:13"></span>
    <span class="p" style="--i:14"></span>
    <span class="p" style="--i:15"></span>
  </div>
  <p class="caption">夏の夜キャンプ</p>
</main>

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

// ── 변수 3개 ──────────────────────────────
$duration: $dur-loop * 1.75;   // 3.5s 기준
$easing: ease-in-out;
$color: $subject-cream;

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

.field { position: absolute; inset: 0; overflow: hidden; pointer-events: none; }

.caption {
  position: relative; z-index: 1; margin: 0;
  color: $subject-cream; font-weight: 700; font-size: clamp(16px, 5vw, 22px); line-height: 1; font-family: inherit;
}

.p {
  position: absolute;
  width: 4px; height: 4px;
  border-radius: 50%;
  background: $color;
  box-shadow: 0 0 12px rgba($color, .8);
  opacity: 0;
  animation: drift $duration $easing infinite;
  animation-delay: calc(var(--i) * -0.37s);
}

@for $i from 1 through 16 {
  .p:nth-child(#{$i}) {
    left: ((($i * 29) % 90)) * 1%;
    top: ((($i * 61) % 78)) * 1%;
    animation-duration: $duration + ($i % 4) * .4s;
  }
}

// 짧게 방향을 바꾸며 떠다니는 불규칙한 궤적 (transform 만)
@keyframes drift {
  0%   { transform: translate(0, 0); opacity: 0; }
  20%  { opacity: .9; }
  35%  { transform: translate(14px, -10px); }
  55%  { transform: translate(-8px, -20px); opacity: .3; }
  70%  { opacity: .85; }
  85%  { transform: translate(10px, -6px); }
  100% { transform: translate(0, 0); opacity: 0; }
}

// ── 접근성: 깜빡임·이동을 멈추고 흐린 점만 남긴다 ────────────
@media (prefers-reduced-motion: reduce) {
  .p { animation: none; opacity: .45; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.field {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}

.caption {
  position: relative;
  z-index: 1;
  margin: 0;
  color: #fff7e6;
  font-weight: 700;
  font-size: clamp(16px, 5vw, 22px);
  line-height: 1;
  font-family: inherit;
}

.p {
  position: absolute;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #fff7e6;
  box-shadow: 0 0 12px rgba(255, 247, 230, 0.8);
  opacity: 0;
  animation: drift 3.5s ease-in-out infinite;
  animation-delay: calc(var(--i) * -0.37s);
}

.p:nth-child(1) {
  left: 29%;
  top: 61%;
  animation-duration: 3.9s;
}

.p:nth-child(2) {
  left: 58%;
  top: 44%;
  animation-duration: 4.3s;
}

.p:nth-child(3) {
  left: 87%;
  top: 27%;
  animation-duration: 4.7s;
}

.p:nth-child(4) {
  left: 26%;
  top: 10%;
  animation-duration: 3.5s;
}

.p:nth-child(5) {
  left: 55%;
  top: 71%;
  animation-duration: 3.9s;
}

.p:nth-child(6) {
  left: 84%;
  top: 54%;
  animation-duration: 4.3s;
}

.p:nth-child(7) {
  left: 23%;
  top: 37%;
  animation-duration: 4.7s;
}

.p:nth-child(8) {
  left: 52%;
  top: 20%;
  animation-duration: 3.5s;
}

.p:nth-child(9) {
  left: 81%;
  top: 3%;
  animation-duration: 3.9s;
}

.p:nth-child(10) {
  left: 20%;
  top: 64%;
  animation-duration: 4.3s;
}

.p:nth-child(11) {
  left: 49%;
  top: 47%;
  animation-duration: 4.7s;
}

.p:nth-child(12) {
  left: 78%;
  top: 30%;
  animation-duration: 3.5s;
}

.p:nth-child(13) {
  left: 17%;
  top: 13%;
  animation-duration: 3.9s;
}

.p:nth-child(14) {
  left: 46%;
  top: 74%;
  animation-duration: 4.3s;
}

.p:nth-child(15) {
  left: 75%;
  top: 57%;
  animation-duration: 4.7s;
}

.p:nth-child(16) {
  left: 14%;
  top: 40%;
  animation-duration: 3.5s;
}

@keyframes drift {
  0% {
    transform: translate(0, 0);
    opacity: 0;
  }
  20% {
    opacity: 0.9;
  }
  35% {
    transform: translate(14px, -10px);
  }
  55% {
    transform: translate(-8px, -20px);
    opacity: 0.3;
  }
  70% {
    opacity: 0.85;
  }
  85% {
    transform: translate(10px, -6px);
  }
  100% {
    transform: translate(0, 0);
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .p {
    animation: none;
    opacity: 0.45;
  }
}

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

export type FirefliesProps = {
  /** 애니메이션 기준 시간(ms) */
  duration?: number;
  /** CSS easing */
  easing?: string;
  /** 피사체 색 */
  color?: string;
};

type Vars = CSSProperties & { "--i"?: number };

const COUNT = 16;

export default function Fireflies({
  duration = 3500,
  easing = "ease-in-out",
  color = "#fff7e6",
}: FirefliesProps) {
  const vars = {
    "--duration": `${duration}ms`,
    "--easing": easing,
    "--color": color,
  } as CSSProperties;

  return (
    <div className={styles.field} style={vars} aria-hidden="true">
      {Array.from({ length: COUNT }, (_, i) => (
        <span key={i} className={styles.p} style={{ "--i": i } as Vars} />
      ))}
    </div>
  );
}