02Grid wave stagger

<main class="stage">
  <div class="grid is-demo">
    <span class="cell">1</span><span class="cell">2</span><span class="cell">3</span>
    <span class="cell">4</span><span class="cell">5</span><span class="cell">6</span>
    <span class="cell">7</span><span class="cell">8</span><span class="cell">9</span>
  </div>
</main>

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

$duration: $dur-base;                              // 칸 하나가 나타나는 시간
$easing: $ease-out;                                // 시작 빠르고 끝은 부드럽게
$wave: 70ms;                                       // (행+열) 1당 시차 계수

@include stage($stage-yellow);

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(5px, 1.8vw, 10px);
  width: min(150px, 50vw);
  aspect-ratio: 1;
}

.cell {
  display: grid;
  place-items: center;
  border-radius: $r-control;
  background: $stage-ink;
  color: $stage-yellow;
  font-weight: 700; font-size: clamp(12px, 3.4vw, 16px); line-height: 1; font-family: inherit;
}

// 반복 재생은 데모 상태에서만 — 정지 상태의 칸은 불투명해야 글자가 읽힌다(옐로 글자 · 먹 면 12.63:1)
.grid.is-demo .cell { animation: wave-loop $dur-loop $easing infinite; }

$cols: 3;
@for $i from 1 through 9 {
  $row: math.floor(math.div($i - 1, $cols));
  $col: ($i - 1) % $cols;
  .grid.is-demo .cell:nth-child(#{$i}) { animation-delay: ($row + $col) * $wave; }
}

@keyframes wave-loop {
  0%, 6%    { opacity: 0; transform: scale(.5); }
  22%, 62%  { opacity: 1; transform: scale(1); }
  84%, 100% { opacity: 0; transform: scale(.7); }
}

@media (prefers-reduced-motion: reduce) {
  .cell { animation: none; opacity: 1; transform: 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);
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(5px, 1.8vw, 10px);
  width: min(150px, 50vw);
  aspect-ratio: 1;
}

.cell {
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: #17141a;
  color: #ffd23f;
  font-weight: 700;
  font-size: clamp(12px, 3.4vw, 16px);
  line-height: 1;
  font-family: inherit;
}

.grid.is-demo .cell {
  animation: wave-loop 2s ease-out infinite;
}

.grid.is-demo .cell:nth-child(1) {
  animation-delay: 0ms;
}

.grid.is-demo .cell:nth-child(2) {
  animation-delay: 70ms;
}

.grid.is-demo .cell:nth-child(3) {
  animation-delay: 140ms;
}

.grid.is-demo .cell:nth-child(4) {
  animation-delay: 70ms;
}

.grid.is-demo .cell:nth-child(5) {
  animation-delay: 140ms;
}

.grid.is-demo .cell:nth-child(6) {
  animation-delay: 210ms;
}

.grid.is-demo .cell:nth-child(7) {
  animation-delay: 140ms;
}

.grid.is-demo .cell:nth-child(8) {
  animation-delay: 210ms;
}

.grid.is-demo .cell:nth-child(9) {
  animation-delay: 280ms;
}

@keyframes wave-loop {
  0%, 6% {
    opacity: 0;
    transform: scale(0.5);
  }
  22%, 62% {
    opacity: 1;
    transform: scale(1);
  }
  84%, 100% {
    opacity: 0;
    transform: scale(0.7);
  }
}
@media (prefers-reduced-motion: reduce) {
  .cell {
    animation: none;
    opacity: 1;
    transform: none;
  }
}

import styles from "./GridWave.module.scss";

export type GridWaveProps = {
  cells?: (string | number)[];
  cols?: number;
  /** (행+열) 1당 시차 ms (기본 70ms) */
  wave?: number;
  duration?: number;
  easing?: string;
};

export default function GridWave({
  cells = [1, 2, 3, 4, 5, 6, 7, 8, 9],
  cols = 3,
  wave = 70,
  duration = 300,
  easing = "ease-out",
}: GridWaveProps) {
  return (
    <div className={styles.grid}>
      {cells.map((cell, i) => {
        const row = Math.floor(i / cols);
        const col = i % cols;
        return (
          <span
            key={i}
            className={styles.cell}
            style={{
              animationDelay: `${(row + col) * wave}ms`,
              animationDuration: "2s",
              transitionDuration: `${duration}ms`,
              transitionTimingFunction: easing,
            }}
          >
            {cell}
          </span>
        );
      })}
    </div>
  );
}