09끊긴 연결을 세어 가며 다시 붙는 상태 띠

<main class="stage">
  <section class="of is-demo" id="of">
    <div class="of__bar" role="status" aria-live="polite">
      <span class="of__dot" aria-hidden="true"></span>
      <span class="of__ic" aria-hidden="true">
        <span class="of__ic-on"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="m238.2 87.69l-104 125.43a8 8 0 0 1-12.3 0L17.8 87.69a7.79 7.79 0 0 1 1.31-11.21a180.75 180.75 0 0 1 217.78 0a7.79 7.79 0 0 1 1.31 11.21" opacity=".2"/><path d="M247.89 80.91a15.93 15.93 0 0 0-6.17-10.81A186.67 186.67 0 0 0 128 32A186.67 186.67 0 0 0 14.28 70.1a15.93 15.93 0 0 0-6.17 10.81a15.65 15.65 0 0 0 3.54 11.89l104 125.43A15.93 15.93 0 0 0 128 224a15.93 15.93 0 0 0 12.31-5.77l104-125.43a15.65 15.65 0 0 0 3.58-11.89M128 208L24.09 82.74A170.76 170.76 0 0 1 128 48a170.76 170.76 0 0 1 103.91 34.74Z"/></g></svg></span>
        <span class="of__ic-off"><svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="m238.2 87.69l-104 125.43a8 8 0 0 1-12.3 0L17.8 87.69a7.79 7.79 0 0 1 1.31-11.21a180.75 180.75 0 0 1 217.78 0a7.79 7.79 0 0 1 1.31 11.21" opacity=".2"/><path d="M53.92 34.62a8 8 0 1 0-11.84 10.76l4.55 5A188 188 0 0 0 14.28 70.1a15.93 15.93 0 0 0-6.17 10.81a15.65 15.65 0 0 0 3.54 11.89l104 125.43A15.93 15.93 0 0 0 128 224a15.93 15.93 0 0 0 12.31-5.77l28.1-33.88l33.67 37a8 8 0 1 0 11.84-10.76ZM128 208L24.09 82.74a171.5 171.5 0 0 1 33.82-19.95l99.63 109.6ZM244.35 92.8l-49.42 59.58a8 8 0 0 1-12.32-10.21l49.3-59.43A170.76 170.76 0 0 0 128 48a175 175 0 0 0-32.39 3a8 8 0 1 1-3-15.72A190.6 190.6 0 0 1 128 32a186.67 186.67 0 0 1 113.72 38.1a15.93 15.93 0 0 1 6.17 10.81a15.65 15.65 0 0 1-3.54 11.89"/></g></svg></span>
      </span>
      <span class="of__msg">
        <span class="of__m of__m--on">연결됨</span>
        <span class="of__m of__m--off">연결이 끊겼어요</span>
        <span class="of__m of__m--back">다시 연결됐어요</span>
      </span>
      <span class="of__side">
        <span class="of__pill of__pill--wait">
          <span class="of__num" aria-hidden="true">
            <span class="of__n" data-sec="3">3</span>
            <span class="of__n" data-sec="2">2</span>
            <span class="of__n" data-sec="1">1</span>
          </span>
          <span class="of__unit">초 뒤 다시 연결</span>
        </span>
        <span class="of__pill of__pill--ok">신호 좋음</span>
      </span>
    </div>

    <div class="of__track" aria-hidden="true">
      <span class="of__rail"></span>
      <span class="of__fill" id="of-fill"></span>
    </div>

    <button class="of__btn" type="button" id="of-btn">연결 끊어 보기</button>
  </section>
</main>

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

// 오프라인·재연결 상태 띠 — 띠는 루프 내내 자리에 남고 안의 문구·색만 한 프레임에 컷으로 바뀐다.
// 컷만으로는 프레임이 모자라므로 남은 시간 막대(scaleX)와 상태 점(translateY)이 사이를 채운다.
$duration: $dur-quick;
$easing: $ease-spring;
$color: $error;

@include stage($stage-ink);

$tick: 1s;   // 카운트다운 한 칸 = JS setInterval 과 같은 길이. 막대가 그 사이를 고르게 눕는다
$cream-soft: rgba(255, 247, 230, .62);
$cream-line: rgba(255, 247, 230, .18);
$ink-veil: rgba(23, 20, 26, .16);

.of {
  box-sizing: border-box;
  display: grid;
  gap: $sp-2;
  width: min(300px, 92vw);
  color: $subject-cream;
}
.of * { box-sizing: border-box; }

// ── 상태 띠 ──
.of__bar {
  display: grid;
  grid-template-columns: auto auto 1fr auto;
  align-items: center;
  gap: $sp-2;
  padding: $sp-2 $sp-3;
  border-radius: $r-pill;
  background: $subject-cream;
  color: $subject-ink;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.2;
  box-shadow: $shadow-press;
  transition: background-color $duration $easing, color $duration $easing;
}
.of.is-off .of__bar { background: $color; color: $subject-cream; }
.of.is-back .of__bar { background: $subject-mint; color: $subject-ink; }

.of__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
}

// 아이콘 두 장을 같은 칸에 겹쳐 두고 컷으로 갈아 끼운다 — 반투명 겹침이 생기지 않는다
.of__ic {
  display: inline-grid;
  font-size: 18px;
  line-height: 1;
}
.of__ic-on,
.of__ic-off {
  grid-area: 1 / 1;
  display: inline-flex;
}
.of__ic-off { opacity: 0; }
.of.is-off .of__ic-on { opacity: 0; }
.of.is-off .of__ic-off { opacity: 1; }

.of__msg { display: inline-grid; }
.of__m {
  grid-area: 1 / 1;
  justify-self: start;
  white-space: nowrap;
}
.of__m--off,
.of__m--back { opacity: 0; }
.of.is-off .of__m--on { opacity: 0; }
.of.is-off .of__m--off { opacity: 1; }
.of.is-back .of__m--on { opacity: 0; }
.of.is-back .of__m--back { opacity: 1; }

// 오른쪽 칸: 두 알약을 같은 자리에 겹쳐 두고 컷으로 갈아 끼운다 — 칸 폭이 바뀌지 않는다
.of__side { display: inline-grid; }
.of__pill {
  grid-area: 1 / 1;
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 0;
  padding: $sp-1 $sp-2;
  border-radius: $r-pill;
  background: $ink-veil;
  font-size: 11px;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
}
.of__pill--wait { opacity: 0; }
.of.is-off .of__pill--wait { opacity: 1; }
.of.is-off .of__pill--ok { opacity: 0; }
.of__num { display: inline-grid; }
.of__n {
  grid-area: 1 / 1;
  justify-self: center;
  opacity: 0;
  font-size: 13px;
  font-weight: 800;
  line-height: 1.2;
}
.of__n.is-now { opacity: 1; }

// ── 남은 시간 막대: 칸 하나에 바탕과 채움을 겹친다 (flex 1 1 0 + scaleX 조합을 쓰지 않는다) ──
.of__track {
  display: grid;
  height: 6px;
  border-radius: $r-pill;
  overflow: hidden;
}
.of__rail,
.of__fill {
  grid-area: 1 / 1;
  width: 100%;
  height: 100%;
  border-radius: $r-pill;
}
.of__rail { background: $cream-line; }
// 채움은 재시도까지 남은 시간이므로 끊긴 동안에만 보인다 — 띠와 레일은 계속 자리에 있다
.of__fill {
  background: $color;
  transform: scaleX(1);
  transform-origin: left center; // 규칙8: 재시도 잔여 막대 좌측 기준
  opacity: 0;
  transition: transform $tick linear, opacity $duration $easing;
}
.of.is-off .of__fill { opacity: 1; }

.of__btn {
  justify-self: start;
  margin: 0;
  padding: $sp-1 $sp-3;
  border: 1px solid $cream-line;
  border-radius: $r-pill;
  background: transparent;
  color: $cream-soft;
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  line-height: 1.4;
  cursor: pointer;
}
.of__btn:focus-visible { outline: 2px solid $subject-cream; outline-offset: 2px; }

// ── 격자 미리보기 전용 2초 루프 ──
// 연결됨 → 끊김(3·2·1) → 재연결됨 → 연결됨. 띠는 한 번도 사라지지 않는다.
@keyframes of-bar {
  0% { background-color: $subject-cream; color: $subject-ink; }
  18% { background-color: $color; color: $subject-cream; }
  72% { background-color: $subject-mint; color: $subject-ink; }
  88%, 100% { background-color: $subject-cream; color: $subject-ink; }
}
@keyframes of-m-on {
  0% { opacity: 1; }
  18% { opacity: 0; }
  88%, 100% { opacity: 1; }
}
@keyframes of-m-off {
  0% { opacity: 0; }
  18% { opacity: 1; }
  72%, 100% { opacity: 0; }
}
@keyframes of-m-back {
  0% { opacity: 0; }
  72% { opacity: 1; }
  88%, 100% { opacity: 0; }
}
@keyframes of-ic-on {
  0% { opacity: 1; }
  18% { opacity: 0; }
  72%, 100% { opacity: 1; }
}
@keyframes of-ic-off {
  0% { opacity: 0; }
  18% { opacity: 1; }
  72%, 100% { opacity: 0; }
}
@keyframes of-pill-wait {
  0% { opacity: 0; }
  18% { opacity: 1; }
  72%, 100% { opacity: 0; }
}
@keyframes of-pill-ok {
  0% { opacity: 1; }
  18% { opacity: 0; }
  72%, 100% { opacity: 1; }
}
@keyframes of-n-3 {
  0% { opacity: 0; }
  18% { opacity: 1; }
  40%, 100% { opacity: 0; }
}
@keyframes of-n-2 {
  0% { opacity: 0; }
  40% { opacity: 1; }
  56%, 100% { opacity: 0; }
}
@keyframes of-n-1 {
  0% { opacity: 0; }
  56% { opacity: 1; }
  72%, 100% { opacity: 0; }
}
// 컷 사이를 채우는 움직임 — 남은 시간이 줄어드는 만큼 막대가 눕는다
@keyframes of-fill {
  0%, 17.99% { transform: scaleX(1); opacity: 0; }
  18% { transform: scaleX(1); opacity: 1; }
  72% { transform: scaleX(0); opacity: 1; }
  72.01%, 100% { transform: scaleX(1); opacity: 0; }
}
@keyframes of-dot {
  0%, 100% { transform: translateY(0); }
  25% { transform: translateY(-3px); }
  50% { transform: translateY(0); }
  75% { transform: translateY(3px); }
}

.of.is-demo {
  .of__bar { animation-name: of-bar; }
  .of__m--on { animation-name: of-m-on; }
  .of__m--off { animation-name: of-m-off; }
  .of__m--back { animation-name: of-m-back; }
  .of__ic-on { animation-name: of-ic-on; }
  .of__ic-off { animation-name: of-ic-off; }
  .of__pill--wait { animation-name: of-pill-wait; }
  .of__pill--ok { animation-name: of-pill-ok; }
  .of__n[data-sec="3"] { animation-name: of-n-3; }
  .of__n[data-sec="2"] { animation-name: of-n-2; }
  .of__n[data-sec="1"] { animation-name: of-n-1; }
  .of__bar,
  .of__m--on,
  .of__m--off,
  .of__m--back,
  .of__ic-on,
  .of__ic-off,
  .of__pill,
  .of__n {
    animation-duration: $dur-loop;
    animation-timing-function: steps(1, end);
    animation-iteration-count: infinite;
    animation-fill-mode: backwards;
  }
  .of__fill {
    animation-name: of-fill;
    animation-duration: $dur-loop;
    animation-timing-function: linear;
    animation-iteration-count: infinite;
    animation-fill-mode: backwards;
  }
  .of__dot {
    animation-name: of-dot;
    animation-duration: $dur-loop;
    animation-timing-function: $easing;
    animation-iteration-count: infinite;
    animation-fill-mode: backwards;
  }
}

@media (max-width: 340px) {
  .of { gap: $sp-1; width: min(292px, 96vw); }
  .of__bar { gap: $sp-1; padding: $sp-1 $sp-2; font-size: 10px; }
  .of__ic { font-size: 14px; }
  .of__dot { width: 6px; height: 6px; }
  .of__pill { padding: 0 $sp-1; font-size: 9px; }
  .of__n { font-size: 11px; }
  .of__btn { padding: 0 $sp-2; font-size: 10px; }
}

@media (prefers-reduced-motion: reduce) {
  .of.is-demo .of__bar,
  .of.is-demo .of__m--on,
  .of.is-demo .of__m--off,
  .of.is-demo .of__m--back,
  .of.is-demo .of__ic-on,
  .of.is-demo .of__ic-off,
  .of.is-demo .of__pill,
  .of.is-demo .of__n,
  .of.is-demo .of__fill,
  .of.is-demo .of__dot { animation: none !important; transition: none !important; }
  // 움직임만 끄고 끊긴 상태의 결과는 읽히도록 남긴다
  .of.is-demo .of__bar { background-color: $color !important; color: $subject-cream !important; }
  .of.is-demo .of__m--on { opacity: 0 !important; }
  .of.is-demo .of__m--off { opacity: 1 !important; }
  .of.is-demo .of__ic-on { opacity: 0 !important; }
  .of.is-demo .of__ic-off { opacity: 1 !important; }
  .of.is-demo .of__pill--wait { opacity: 1 !important; }
  .of.is-demo .of__pill--ok { opacity: 0 !important; }
  .of.is-demo .of__n[data-sec="3"] { opacity: 1 !important; }
  .of.is-demo .of__fill { transform: scaleX(1) !important; opacity: 1 !important; }
  .of.is-demo .of__dot { transform: none !important; }
}

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);
}

.of {
  box-sizing: border-box;
  display: grid;
  gap: 8px;
  width: min(300px, 92vw);
  color: #fff7e6;
}

.of * {
  box-sizing: border-box;
}

.of__bar {
  display: grid;
  grid-template-columns: auto auto 1fr auto;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  background: #fff7e6;
  color: #17141a;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.2;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transition: background-color 220ms cubic-bezier(0.2, 0.8, 0.2, 1), color 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.of.is-off .of__bar {
  background: #c2361a;
  color: #fff7e6;
}

.of.is-back .of__bar {
  background: #4cd4a6;
  color: #17141a;
}

.of__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
}

.of__ic {
  display: inline-grid;
  font-size: 18px;
  line-height: 1;
}

.of__ic-on,
.of__ic-off {
  grid-area: 1/1;
  display: inline-flex;
}

.of__ic-off {
  opacity: 0;
}

.of.is-off .of__ic-on {
  opacity: 0;
}

.of.is-off .of__ic-off {
  opacity: 1;
}

.of__msg {
  display: inline-grid;
}

.of__m {
  grid-area: 1/1;
  justify-self: start;
  white-space: nowrap;
}

.of__m--off,
.of__m--back {
  opacity: 0;
}

.of.is-off .of__m--on {
  opacity: 0;
}

.of.is-off .of__m--off {
  opacity: 1;
}

.of.is-back .of__m--on {
  opacity: 0;
}

.of.is-back .of__m--back {
  opacity: 1;
}

.of__side {
  display: inline-grid;
}

.of__pill {
  grid-area: 1/1;
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 0;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.16);
  font-size: 11px;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
}

.of__pill--wait {
  opacity: 0;
}

.of.is-off .of__pill--wait {
  opacity: 1;
}

.of.is-off .of__pill--ok {
  opacity: 0;
}

.of__num {
  display: inline-grid;
}

.of__n {
  grid-area: 1/1;
  justify-self: center;
  opacity: 0;
  font-size: 13px;
  font-weight: 800;
  line-height: 1.2;
}

.of__n.is-now {
  opacity: 1;
}

.of__track {
  display: grid;
  height: 6px;
  border-radius: 999px;
  overflow: hidden;
}

.of__rail,
.of__fill {
  grid-area: 1/1;
  width: 100%;
  height: 100%;
  border-radius: 999px;
}

.of__rail {
  background: rgba(255, 247, 230, 0.18);
}

.of__fill {
  background: #c2361a;
  transform: scaleX(1);
  transform-origin: left center;
  opacity: 0;
  transition: transform 1s linear, opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.of.is-off .of__fill {
  opacity: 1;
}

.of__btn {
  justify-self: start;
  margin: 0;
  padding: 4px 12px;
  border: 1px solid rgba(255, 247, 230, 0.18);
  border-radius: 999px;
  background: transparent;
  color: rgba(255, 247, 230, 0.62);
  font-family: inherit;
  font-size: 11px;
  font-weight: 700;
  line-height: 1.4;
  cursor: pointer;
}

.of__btn:focus-visible {
  outline: 2px solid #fff7e6;
  outline-offset: 2px;
}

@keyframes of-bar {
  0% {
    background-color: #fff7e6;
    color: #17141a;
  }
  18% {
    background-color: #c2361a;
    color: #fff7e6;
  }
  72% {
    background-color: #4cd4a6;
    color: #17141a;
  }
  88%, 100% {
    background-color: #fff7e6;
    color: #17141a;
  }
}
@keyframes of-m-on {
  0% {
    opacity: 1;
  }
  18% {
    opacity: 0;
  }
  88%, 100% {
    opacity: 1;
  }
}
@keyframes of-m-off {
  0% {
    opacity: 0;
  }
  18% {
    opacity: 1;
  }
  72%, 100% {
    opacity: 0;
  }
}
@keyframes of-m-back {
  0% {
    opacity: 0;
  }
  72% {
    opacity: 1;
  }
  88%, 100% {
    opacity: 0;
  }
}
@keyframes of-ic-on {
  0% {
    opacity: 1;
  }
  18% {
    opacity: 0;
  }
  72%, 100% {
    opacity: 1;
  }
}
@keyframes of-ic-off {
  0% {
    opacity: 0;
  }
  18% {
    opacity: 1;
  }
  72%, 100% {
    opacity: 0;
  }
}
@keyframes of-pill-wait {
  0% {
    opacity: 0;
  }
  18% {
    opacity: 1;
  }
  72%, 100% {
    opacity: 0;
  }
}
@keyframes of-pill-ok {
  0% {
    opacity: 1;
  }
  18% {
    opacity: 0;
  }
  72%, 100% {
    opacity: 1;
  }
}
@keyframes of-n-3 {
  0% {
    opacity: 0;
  }
  18% {
    opacity: 1;
  }
  40%, 100% {
    opacity: 0;
  }
}
@keyframes of-n-2 {
  0% {
    opacity: 0;
  }
  40% {
    opacity: 1;
  }
  56%, 100% {
    opacity: 0;
  }
}
@keyframes of-n-1 {
  0% {
    opacity: 0;
  }
  56% {
    opacity: 1;
  }
  72%, 100% {
    opacity: 0;
  }
}
@keyframes of-fill {
  0%, 17.99% {
    transform: scaleX(1);
    opacity: 0;
  }
  18% {
    transform: scaleX(1);
    opacity: 1;
  }
  72% {
    transform: scaleX(0);
    opacity: 1;
  }
  72.01%, 100% {
    transform: scaleX(1);
    opacity: 0;
  }
}
@keyframes of-dot {
  0%, 100% {
    transform: translateY(0);
  }
  25% {
    transform: translateY(-3px);
  }
  50% {
    transform: translateY(0);
  }
  75% {
    transform: translateY(3px);
  }
}
.of.is-demo .of__bar {
  animation-name: of-bar;
}
.of.is-demo .of__m--on {
  animation-name: of-m-on;
}
.of.is-demo .of__m--off {
  animation-name: of-m-off;
}
.of.is-demo .of__m--back {
  animation-name: of-m-back;
}
.of.is-demo .of__ic-on {
  animation-name: of-ic-on;
}
.of.is-demo .of__ic-off {
  animation-name: of-ic-off;
}
.of.is-demo .of__pill--wait {
  animation-name: of-pill-wait;
}
.of.is-demo .of__pill--ok {
  animation-name: of-pill-ok;
}
.of.is-demo .of__n[data-sec="3"] {
  animation-name: of-n-3;
}
.of.is-demo .of__n[data-sec="2"] {
  animation-name: of-n-2;
}
.of.is-demo .of__n[data-sec="1"] {
  animation-name: of-n-1;
}
.of.is-demo .of__bar,
.of.is-demo .of__m--on,
.of.is-demo .of__m--off,
.of.is-demo .of__m--back,
.of.is-demo .of__ic-on,
.of.is-demo .of__ic-off,
.of.is-demo .of__pill,
.of.is-demo .of__n {
  animation-duration: 2s;
  animation-timing-function: steps(1, end);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}
.of.is-demo .of__fill {
  animation-name: of-fill;
  animation-duration: 2s;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}
.of.is-demo .of__dot {
  animation-name: of-dot;
  animation-duration: 2s;
  animation-timing-function: cubic-bezier(0.2, 0.8, 0.2, 1);
  animation-iteration-count: infinite;
  animation-fill-mode: backwards;
}

@media (max-width: 340px) {
  .of {
    gap: 4px;
    width: min(292px, 96vw);
  }
  .of__bar {
    gap: 4px;
    padding: 4px 8px;
    font-size: 10px;
  }
  .of__ic {
    font-size: 14px;
  }
  .of__dot {
    width: 6px;
    height: 6px;
  }
  .of__pill {
    padding: 0 4px;
    font-size: 9px;
  }
  .of__n {
    font-size: 11px;
  }
  .of__btn {
    padding: 0 8px;
    font-size: 10px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .of.is-demo .of__bar,
  .of.is-demo .of__m--on,
  .of.is-demo .of__m--off,
  .of.is-demo .of__m--back,
  .of.is-demo .of__ic-on,
  .of.is-demo .of__ic-off,
  .of.is-demo .of__pill,
  .of.is-demo .of__n,
  .of.is-demo .of__fill,
  .of.is-demo .of__dot {
    animation: none !important;
    transition: none !important;
  }
  .of.is-demo .of__bar {
    background-color: #c2361a !important;
    color: #fff7e6 !important;
  }
  .of.is-demo .of__m--on {
    opacity: 0 !important;
  }
  .of.is-demo .of__m--off {
    opacity: 1 !important;
  }
  .of.is-demo .of__ic-on {
    opacity: 0 !important;
  }
  .of.is-demo .of__ic-off {
    opacity: 1 !important;
  }
  .of.is-demo .of__pill--wait {
    opacity: 1 !important;
  }
  .of.is-demo .of__pill--ok {
    opacity: 0 !important;
  }
  .of.is-demo .of__n[data-sec="3"] {
    opacity: 1 !important;
  }
  .of.is-demo .of__fill {
    transform: scaleX(1) !important;
    opacity: 1 !important;
  }
  .of.is-demo .of__dot {
    transform: none !important;
  }
}

// 상태 띠는 사라지지 않는다 — 안의 문구와 색만 바뀐다. 진짜 연결 상태는 navigator.onLine 이 알려 준다.
var of = document.getElementById('of');
var ofBtn = document.getElementById('of-btn');
var ofFill = document.getElementById('of-fill');
var ofNums = [].slice.call(of.querySelectorAll('.of__n'));
var ofTimer = 0;
function ofSec(n) {
  ofNums.forEach(function (s) { s.classList.toggle('is-now', Number(s.dataset.sec) === n); });
  ofFill.style.transform = 'scaleX(' + (n / 3) + ')';
}
function ofState(s) {
  of.classList.remove('is-demo');
  of.classList.toggle('is-off', s === 'off');
  of.classList.toggle('is-back', s === 'back');
  ofBtn.textContent = s === 'off' ? '연결 되돌리기' : '연결 끊어 보기';
}
function ofDrop() {
  ofState('off');
  var n = 3;
  ofSec(n);
  clearInterval(ofTimer);
  ofTimer = setInterval(function () {
    n -= 1;
    if (n > 0) { ofSec(n); return; }
    clearInterval(ofTimer);
    ofSec(0);
    ofState('back');
  }, 1000);
}
function ofUp() {
  clearInterval(ofTimer);
  ofSec(0);
  ofState('back');
}
ofBtn.addEventListener('click', function () {
  if (of.classList.contains('is-off')) ofUp(); else ofDrop();
});
if (!navigator.onLine) ofDrop();
window.addEventListener('offline', ofDrop);
window.addEventListener('online', ofUp);

import { useState, useEffect } from "react";
import type { CSSProperties } from "react";
import styles from "./OfflineRetryBanner.module.scss";

export type OfflineRetryBannerProps = {
  onlineText?: string;
  offlineText?: string;
  backText?: string;
  /** 온라인일 때 오른쪽 알약에 들어가는 짧은 라벨 */
  okLabel?: string;
  /** 카운트다운 숫자 뒤에 붙는 말 */
  unitLabel?: string;
  dropLabel?: string;
  restoreLabel?: string;
  /** 재시도까지 세는 초 */
  seconds?: number;
  /** 격자 미리보기용 2초 자동 루프. 사람이 손대면 꺼진다 */
  demo?: boolean;
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };
type Status = "on" | "off" | "back";
// ambient 가 얇다 — 브라우저 전역 중 쓰는 것만 로컬 타입으로 좁혀 받는다
type Host = {
  setInterval(fn: () => void, ms: number): number;
  clearInterval(id: number): void;
  addEventListener(type: string, fn: () => void): void;
  removeEventListener(type: string, fn: () => void): void;
  navigator: { onLine: boolean };
};

const host = globalThis as unknown as Host;

function WifiOnIcon() {
  return (
    <svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="m238.2 87.69l-104 125.43a8 8 0 0 1-12.3 0L17.8 87.69a7.79 7.79 0 0 1 1.31-11.21a180.75 180.75 0 0 1 217.78 0a7.79 7.79 0 0 1 1.31 11.21" opacity=".2"/><path d="M247.89 80.91a15.93 15.93 0 0 0-6.17-10.81A186.67 186.67 0 0 0 128 32A186.67 186.67 0 0 0 14.28 70.1a15.93 15.93 0 0 0-6.17 10.81a15.65 15.65 0 0 0 3.54 11.89l104 125.43A15.93 15.93 0 0 0 128 224a15.93 15.93 0 0 0 12.31-5.77l104-125.43a15.65 15.65 0 0 0 3.58-11.89M128 208L24.09 82.74A170.76 170.76 0 0 1 128 48a170.76 170.76 0 0 1 103.91 34.74Z"/></g></svg>
  );
}

function WifiOffIcon() {
  return (
    <svg viewBox="0 0 256 256" width="1em" height="1em" fill="currentColor"><g><path d="m238.2 87.69l-104 125.43a8 8 0 0 1-12.3 0L17.8 87.69a7.79 7.79 0 0 1 1.31-11.21a180.75 180.75 0 0 1 217.78 0a7.79 7.79 0 0 1 1.31 11.21" opacity=".2"/><path d="M53.92 34.62a8 8 0 1 0-11.84 10.76l4.55 5A188 188 0 0 0 14.28 70.1a15.93 15.93 0 0 0-6.17 10.81a15.65 15.65 0 0 0 3.54 11.89l104 125.43A15.93 15.93 0 0 0 128 224a15.93 15.93 0 0 0 12.31-5.77l28.1-33.88l33.67 37a8 8 0 1 0 11.84-10.76ZM128 208L24.09 82.74a171.5 171.5 0 0 1 33.82-19.95l99.63 109.6ZM244.35 92.8l-49.42 59.58a8 8 0 0 1-12.32-10.21l49.3-59.43A170.76 170.76 0 0 0 128 48a175 175 0 0 0-32.39 3a8 8 0 1 1-3-15.72A190.6 190.6 0 0 1 128 32a186.67 186.67 0 0 1 113.72 38.1a15.93 15.93 0 0 1 6.17 10.81a15.65 15.65 0 0 1-3.54 11.89"/></g></svg>
  );
}

export default function OfflineRetryBanner({
  onlineText = "Connected",
  offlineText = "You are offline",
  backText = "Back online",
  okLabel = "Good signal",
  unitLabel = "s until retry",
  dropLabel = "Drop the connection",
  restoreLabel = "Bring it back",
  seconds = 3,
  demo = true,
  duration = 220,
  easing = "cubic-bezier(.2,.8,.2,1)",
  color = "#c2361a",
}: OfflineRetryBannerProps) {
  const [live, setLive] = useState(demo);
  const [status, setStatus] = useState<Status>("on");
  const [left, setLeft] = useState(0);

  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };

  function drop() {
    setLive(false);
    setLeft(seconds);
    setStatus("off");
  }

  function restore() {
    setLive(false);
    setLeft(0);
    setStatus("back");
  }

  // 끊긴 동안에만 1초마다 한 칸씩 센다
  useEffect(() => {
    if (status !== "off") return;
    const id = host.setInterval(() => setLeft((p: number) => (p > 0 ? p - 1 : 0)), 1000);
    return () => host.clearInterval(id);
  }, [status]);

  useEffect(() => {
    if (status === "off" && left <= 0) setStatus("back");
  }, [status, left]);

  // 진짜 연결 상태도 읽는다
  useEffect(() => {
    const goOff = () => drop();
    const goOn = () => restore();
    host.addEventListener("offline", goOff);
    host.addEventListener("online", goOn);
    if (host.navigator && host.navigator.onLine === false) goOff();
    return () => {
      host.removeEventListener("offline", goOff);
      host.removeEventListener("online", goOn);
    };
  }, [seconds]);

  const cls = [
    styles.of,
    live ? styles.isDemo : "",
    status === "off" ? styles.isOff : "",
    status === "back" ? styles.isBack : "",
  ]
    .filter(Boolean)
    .join(" ");

  const ratio = seconds > 0 ? left / seconds : 0;
  // 세 문구·두 알약을 같은 자리에 겹쳐 두고 컷으로 갈아 끼운다 — 반투명 겹침도 칸 폭 변화도 없다
  const ticks: number[] = [];
  for (let n = seconds; n > 0; n -= 1) ticks.push(n);

  return (
    <section className={cls} style={vars}>
      {/* 띠는 사라지지 않는다 — 안의 문구와 색만 바뀐다 */}
      <div className={styles.bar} role="status" aria-live="polite">
        <span className={styles.dot} aria-hidden="true" />
        <span className={styles.ic} aria-hidden="true">
          <span className={styles.icOn}><WifiOnIcon /></span>
          <span className={styles.icOff}><WifiOffIcon /></span>
        </span>
        <span className={styles.msg}>
          <span className={[styles.m, styles.mOn].join(" ")}>{onlineText}</span>
          <span className={[styles.m, styles.mOff].join(" ")}>{offlineText}</span>
          <span className={[styles.m, styles.mBack].join(" ")}>{backText}</span>
        </span>
        <span className={styles.side}>
          <span className={[styles.pill, styles.pillWait].join(" ")}>
            <span className={styles.num} aria-hidden="true">
              {ticks.map((n) => (
                <span
                  key={n}
                  className={[styles.n, n === left ? styles.isNow : ""].filter(Boolean).join(" ")}
                  data-sec={n}
                >
                  {n}
                </span>
              ))}
            </span>
            <span className={styles.unit}>{unitLabel}</span>
          </span>
          <span className={[styles.pill, styles.pillOk].join(" ")}>{okLabel}</span>
        </span>
      </div>

      <div className={styles.track} aria-hidden="true">
        <span className={styles.rail} />
        <span className={styles.fill} style={{ transform: `scaleX(${status === "off" ? ratio : 1})` }} />
      </div>

      <button className={styles.btn} type="button" onClick={status === "off" ? restore : drop}>
        {status === "off" ? restoreLabel : dropLabel}
      </button>
    </section>
  );
}