09Reduced-motion static download notice — with reduced motion, only the progress value's label changes instead of animating

<main class="stage">
<div class="drm is-demo" id="drm">
  <div class="drm__col">
    <span class="drm__colLabel">Normal motion</span>
    <div class="drm__track"><div class="drm__fill" id="drmFillA"></div></div>
    <span class="drm__pct" id="drmPctA">0%</span>
  </div>
  <div class="drm__col drm__col--reduced">
    <span class="drm__colLabel">Reduced motion</span>
    <div class="drm__staticBox"><span class="drm__pct" id="drmPctB">0%</span></div>
  </div>
  <button class="drm__btn" id="drmBtn" type="button">Switch to reduced motion</button>
</div>
</main>

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

// 계산 겹: 진행 값 하나를 두 판이 다르게 그린다 — 왼쪽 transform 갱신 · 오른쪽 문구만 교체 — index.html paint() 참조
@include stage($stage-ink);

.drm {
  width: 100%;
  max-width: 260px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: $sp-3;
}

.drm__col {
  display: grid;
  justify-items: center;
  gap: $sp-2;
}

.drm__colLabel {
  font: 600 11px/1.2 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: rgba($subject-cream, .8);
  text-align: center;
}

.drm__track {
  width: 100%;
  height: $sp-2;
  border-radius: $r-pill;
  background: rgba($subject-cream, .16);
  overflow: hidden;
}

.drm__fill {
  height: 100%;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(0);
  border-radius: $r-pill;
  background: $subject-blue-light;
  transition: transform $dur-instant linear;
}

.drm--force-reduce .drm__fill { transition: none; }

.drm__pct {
  font: 700 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: $subject-cream;
  font-variant-numeric: tabular-nums;
}

.drm__staticBox {
  width: 100%;
  min-height: $sp-2;
  padding: $sp-1 0;
  border-radius: $r-sm;
  background: rgba($subject-cream, .16);
  display: grid;
  place-items: center;
  // 의도적으로 막대·위치를 움직이지 않는다 — 모션 감소 판은 문구 교체만(둥근 칩, 진행 막대 아님)
}

.drm__btn {
  grid-column: 1 / -1;
  width: 100%;
  border: 0;
  border-radius: $r-control;
  padding: $sp-2 $sp-4;
  background: $subject-cream;
  color: $stage-ink;
  font: 700 11px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform $dur-instant $ease-out;

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

@media (max-width: 340px) {
  .drm { max-width: 210px; gap: $sp-2; }
  .drm__colLabel { font-size: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  .drm__fill { transition: none; }
  .drm__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: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.drm {
  width: 100%;
  max-width: 260px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.drm__col {
  display: grid;
  justify-items: center;
  gap: 8px;
}

.drm__colLabel {
  font: 600 11px/1.2 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: rgba(255, 247, 230, 0.8);
  text-align: center;
}

.drm__track {
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.16);
  overflow: hidden;
}

.drm__fill {
  height: 100%;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(0);
  border-radius: 999px;
  background: #5b8cf8;
  transition: transform 140ms linear;
}

.drm--force-reduce .drm__fill {
  transition: none;
}

.drm__pct {
  font: 700 13px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #fff7e6;
  font-variant-numeric: tabular-nums;
}

.drm__staticBox {
  width: 100%;
  min-height: 8px;
  padding: 4px 0;
  border-radius: 8px;
  background: rgba(255, 247, 230, 0.16);
  display: grid;
  place-items: center;
}

.drm__btn {
  grid-column: 1/-1;
  width: 100%;
  border: 0;
  border-radius: 12px;
  padding: 8px 16px;
  background: #fff7e6;
  color: #17141a;
  font: 700 11px/1 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.drm__btn:active {
  transform: scale(0.96);
}

@media (max-width: 340px) {
  .drm {
    max-width: 210px;
    gap: 8px;
  }
  .drm__colLabel {
    font-size: 10px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .drm__fill {
    transition: none;
  }
  .drm__btn {
    transition: none;
  }
}

(function () {
  var root = document.getElementById('drm');
  var fillA = document.getElementById('drmFillA');
  var pctA = document.getElementById('drmPctA');
  var pctB = document.getElementById('drmPctB');
  var btn = document.getElementById('drmBtn');

  // 상수: In progress 속도(%/틱) · 틱 간격(ms)
  var STEP = 4;
  var TICK_MS = 130;
  var forcedReduce = false;

  var pct = 0;

  // 계산 겹: 같은 In progress 값 하나를 두 판이 다르게 그린다 — 왼쪽은 매 틱 transform 갱신, 오른쪽은 문구만 교체(레이아웃·트랜지션 0)
  function paint() {
    fillA.style.transform = 'scaleX(' + (pct / 100).toFixed(3) + ')';
    pctA.textContent = pct + '%';
    pctB.textContent = pct + '%';
  }

  function tick() {
    pct = (pct + STEP) % 101;
    paint();
    setTimeout(tick, TICK_MS);
  }
  tick();

  btn.addEventListener('click', function () {
    root.classList.remove('is-demo');
    forcedReduce = !forcedReduce;
    root.classList.toggle('drm--force-reduce', forcedReduce);
    btn.textContent = forcedReduce ? 'Switch to normal motion' : 'Switch to reduced motion';
  });
})();

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

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

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

  useEffect(() => {
    const root = rootRef.current;
    if (!root) return;
    const fillA = root.querySelector(`.${styles.fill}`) as HTMLElement | null;
    const pctA = root.querySelector(`.${styles.pctA}`) as HTMLElement | null;
    const pctB = root.querySelector(`.${styles.pctB}`) as HTMLElement | null;
    const btn = root.querySelector(`.${styles.btn}`) as HTMLElement | null;
    if (!fillA || !pctA || !pctB || !btn) return;

    // 상수: 진행 속도(%/틱) · 틱 간격(ms)
    const STEP = 4;
    const TICK_MS = 130;
    let forcedReduce = false;
    let pct = 0;
    let timer = 0;
    let stopped = false;

    // 계산 겹: 같은 진행 값 하나를 두 판이 다르게 그린다 — 왼쪽은 매 틱 transform 갱신, 오른쪽은 문구만 교체(레이아웃·트랜지션 0)
    function paint() {
      fillA!.style.transform = "scaleX(" + (pct / 100).toFixed(3) + ")";
      pctA!.textContent = pct + "%";
      pctB!.textContent = pct + "%";
    }

    function tick() {
      if (stopped) return;
      pct = (pct + STEP) % 101;
      paint();
      timer = window.setTimeout(tick, TICK_MS);
    }
    tick();

    function onClick() {
      root!.classList.remove(styles["is-demo"]);
      forcedReduce = !forcedReduce;
      root!.classList.toggle(styles["drm--force-reduce"], forcedReduce);
      btn!.textContent = forcedReduce ? "일반 모션 전환" : "모션 감소 전환";
    }
    btn.addEventListener("click", onClick);

    return () => {
      stopped = true;
      window.clearTimeout(timer);
      btn.removeEventListener("click", onClick);
    };
  }, []);

  return (
    <div ref={rootRef} className={`${styles.stage} ${styles.drm} ${styles["is-demo"]}`}>
      <div className={styles.col}>
        <span className={styles.colLabel}>일반 모션</span>
        <div className={styles.track}><div className={styles.fill} /></div>
        <span className={`${styles.pct} ${styles.pctA}`}>0%</span>
      </div>
      <div className={`${styles.col} ${styles["col--reduced"]}`}>
        <span className={styles.colLabel}>모션 감소</span>
        <div className={styles.staticBox}><span className={`${styles.pct} ${styles.pctB}`}>0%</span></div>
      </div>
      <button className={styles.btn} type="button">모션 감소 전환</button>
    </div>
  );
}