01Saving-label pulse — the saving label's brightness value rises and falls repeatedly while a save is in progress

<main class="stage">
<div class="ssp is-demo" id="ssp">
  <div class="ssp__card">
    <span class="ssp__dot" id="sspDot"></span>
    <span class="ssp__label" id="sspLabel">Saving</span>
    <span class="ssp__dots" aria-hidden="true">
      <span class="ssp__d" id="sspD0"></span><span class="ssp__d" id="sspD1"></span><span class="ssp__d" id="sspD2"></span>
    </span>
  </div>
  <button class="ssp__btn" id="sspBtn" type="button">Save now</button>
</div>
</main>

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

// 계산 겹: 문구 밝기 값 = 경과시간÷주기 위상의 sin 진폭, 점 세 개는 위상을 어긋내 순차 점멸 — index.html 참조
@include stage($stage-yellow);

.ssp__card {
  display: flex;
  align-items: center;
  gap: $sp-2;
  padding: $sp-3 $sp-5;
  border-radius: $r-card;
  background: $stage-ink;
}

.ssp__dot {
  width: $sp-2;
  height: $sp-2;
  border-radius: $r-pill;
  background: $subject-blue-light;
  flex: 0 0 auto;
}

.ssp--done .ssp__dot { background: $subject-mint; }

.ssp__label {
  font: 700 15px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-cream;
  min-width: 64px;
}

.ssp__dots {
  display: flex;
  gap: 4px;
}

.ssp__d {
  width: 4px;
  height: 4px;
  border-radius: $r-pill;
  background: $subject-cream;
}

.ssp__btn {
  margin-top: $sp-4;
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $stage-ink;
  color: $subject-cream;
  font: 700 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

  &:active { transform: scale(.96); }
}

.ssp { display: grid; justify-items: center; }

@media (max-width: 340px) {
  .ssp__card { padding: $sp-2 $sp-4; }
  .ssp__label { font-size: 13px; min-width: 56px; }
}

@media (prefers-reduced-motion: reduce) {
  .ssp__btn { transition: 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);
}

.ssp__card {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 16px;
  background: #17141a;
}

.ssp__dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #5b8cf8;
  flex: 0 0 auto;
}

.ssp--done .ssp__dot {
  background: #4cd4a6;
}

.ssp__label {
  font: 700 15px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #fff7e6;
  min-width: 64px;
}

.ssp__dots {
  display: flex;
  gap: 4px;
}

.ssp__d {
  width: 4px;
  height: 4px;
  border-radius: 999px;
  background: #fff7e6;
}

.ssp__btn {
  margin-top: 16px;
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #17141a;
  color: #fff7e6;
  font: 700 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.ssp__btn:active {
  transform: scale(0.96);
}

.ssp {
  display: grid;
  justify-items: center;
}

@media (max-width: 340px) {
  .ssp__card {
    padding: 8px 16px;
  }
  .ssp__label {
    font-size: 13px;
    min-width: 56px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ssp__btn {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('ssp');
  var btn = document.getElementById('sspBtn');
  var label = document.getElementById('sspLabel');
  var dot = document.getElementById('sspDot');
  var dots = [document.getElementById('sspD0'), document.getElementById('sspD1'), document.getElementById('sspD2')];

  // 상수: 펄스 한 주기 · 점 세 개의 위상 차 · Saving 유지시간 · Saved 유지시간
  var PULSE_PERIOD_MS = 900;
  var DOT_STAGGER_MS = 160;
  var SAVING_MS = 2400;
  var IDLE_MS = 1000;

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var phase = 'saving';
  var phaseStart = null;

  // 계산 겹: 문구 밝기 값 = 경과시간을 주기로 나눈 위상의 sin 진폭, 점마다 위상을 어긋내 순차로 밝아진다
  function raf(ts) {
    if (phaseStart === null) phaseStart = ts;
    var el = ts - phaseStart;
    if (phase === 'saving') {
      if (reduce) {
        label.style.opacity = '1';
        dots.forEach(function (d) { d.style.opacity = '.6'; });
      } else {
        var t = (el % PULSE_PERIOD_MS) / PULSE_PERIOD_MS;
        var op = 0.45 + 0.55 * (0.5 + 0.5 * Math.sin(t * Math.PI * 2));
        label.style.opacity = op.toFixed(3);
        dots.forEach(function (d, i) {
          var dop = 0.2 + 0.8 * Math.abs(Math.sin((el - i * DOT_STAGGER_MS) / PULSE_PERIOD_MS * Math.PI));
          d.style.opacity = dop.toFixed(3);
        });
      }
      if (el > SAVING_MS) {
        phase = 'idle';
        phaseStart = ts;
        label.textContent = 'Saved';
        label.style.opacity = '1';
        dots.forEach(function (d) { d.style.opacity = '0'; });
        root.classList.add('ssp--done');
      }
    } else {
      if (el > IDLE_MS) {
        phase = 'saving';
        phaseStart = ts;
        label.textContent = 'Saving';
        root.classList.remove('ssp--done');
      }
    }
    requestAnimationFrame(raf);
  }
  requestAnimationFrame(raf);

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    phase = 'saving';
    phaseStart = null;
    label.textContent = 'Saving';
    root.classList.remove('ssp--done');
  });
})();

import { useEffect, useRef } from "react";
import styles from "./SaveStatusSavingPulse.module.scss";

type Box<T> = { current: T };

export default function SaveStatusSavingPulse() {
  const rootRef = useRef(null) as unknown as Box<HTMLDivElement | null>;

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const label = root.querySelector(`.${styles.label}`) as HTMLElement | null;
    const dotEls = Array.from(root.querySelectorAll(`.${styles.d}`)) as HTMLElement[];
    const btn = root.querySelector(`.${styles.btn}`) as HTMLElement | null;
    if (!label || !btn || dotEls.length < 3) return;

    // 상수: 펄스 한 주기 · 점 세 개의 위상 차 · 저장 중 유지시간 · 저장됨 유지시간
    const PULSE_PERIOD_MS = 900;
    const DOT_STAGGER_MS = 160;
    const SAVING_MS = 2400;
    const IDLE_MS = 1000;

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let phase: "saving" | "idle" = "saving";
    let phaseStart: number | null = null;
    let rafId = 0;

    // 계산 겹: 문구 밝기 값 = 경과시간을 주기로 나눈 위상의 sin 진폭, 점마다 위상을 어긋내 순차로 밝아진다
    function raf(ts: number) {
      if (phaseStart === null) phaseStart = ts;
      const el = ts - phaseStart;
      if (phase === "saving") {
        if (reduce) {
          label!.style.opacity = "1";
          dotEls.forEach((d) => { d.style.opacity = ".6"; });
        } else {
          const t = (el % PULSE_PERIOD_MS) / PULSE_PERIOD_MS;
          const op = 0.45 + 0.55 * (0.5 + 0.5 * Math.sin(t * Math.PI * 2));
          label!.style.opacity = op.toFixed(3);
          dotEls.forEach((d, i) => {
            const dop = 0.2 + 0.8 * Math.abs(Math.sin((el - i * DOT_STAGGER_MS) / PULSE_PERIOD_MS * Math.PI));
            d.style.opacity = dop.toFixed(3);
          });
        }
        if (el > SAVING_MS) {
          phase = "idle"; phaseStart = ts;
          label!.textContent = "저장됨";
          label!.style.opacity = "1";
          dotEls.forEach((d) => { d.style.opacity = "0"; });
          root!.classList.add(styles["ssp--done"]);
        }
      } else {
        if (el > IDLE_MS) {
          phase = "saving"; phaseStart = ts;
          label!.textContent = "저장 중";
          root!.classList.remove(styles["ssp--done"]);
        }
      }
      rafId = requestAnimationFrame(raf);
    }
    rafId = requestAnimationFrame(raf);

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      phase = "saving"; phaseStart = null;
      label!.textContent = "저장 중";
      root!.classList.remove(styles["ssp--done"]);
    }
    btn.addEventListener("click", onClick);

    return () => {
      cancelAnimationFrame(rafId);
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.ssp} ${styles["is-demo"]}`}>
      <div className={styles.card}>
        <span className={styles.dot} />
        <span className={styles.label}>저장 중</span>
        <span className={styles.dots} aria-hidden="true">
          <span className={styles.d} />
          <span className={styles.d} />
          <span className={styles.d} />
        </span>
      </div>
      <button className={styles.btn} type="button">지금 저장</button>
    </div>
  );
}