Coming-soon page with countdown

<main class="grid min-h-screen place-items-center bg-slate-950 px-4 text-center text-white">
  <div>
    <p class="text-sm font-semibold uppercase tracking-widest text-indigo-300">Acme Studio</p>
    <h1 class="mt-4 text-balance text-4xl font-bold sm:text-6xl">Something new is on its way</h1>

    <time id="launch" datetime="2027-01-15T09:00:00+00:00" data-launch="2027-01-15T09:00:00+00:00"
      class="mt-10 grid grid-cols-4 gap-3 sm:gap-6">
      <div class="rounded-xl bg-white/10 p-4"><span id="cd-d" class="block text-3xl font-bold tabular-nums sm:text-5xl">--</span><span class="text-xs text-slate-300">Days</span></div>
      <div class="rounded-xl bg-white/10 p-4"><span id="cd-h" class="block text-3xl font-bold tabular-nums sm:text-5xl">--</span><span class="text-xs text-slate-300">Hours</span></div>
      <div class="rounded-xl bg-white/10 p-4"><span id="cd-m" class="block text-3xl font-bold tabular-nums sm:text-5xl">--</span><span class="text-xs text-slate-300">Minutes</span></div>
      <div class="rounded-xl bg-white/10 p-4"><span id="cd-s" class="block text-3xl font-bold tabular-nums sm:text-5xl">--</span><span class="text-xs text-slate-300">Seconds</span></div>
    </time>

    <p id="cd-live" class="sr-only" aria-live="polite"></p>
    <p id="cd-done" class="mt-10 hidden text-xl">We have launched. Welcome!</p>
    <noscript><p class="mt-6 text-slate-300">We launch on 15 January 2027.</p></noscript>
  </div>
</main>

const target = new Date(document.getElementById('launch').dataset.launch).getTime();
const cells = { d: 'cd-d', h: 'cd-h', m: 'cd-m', s: 'cd-s' };
const set = (k, v) => (document.getElementById(cells[k]).textContent = String(v).padStart(2, '0'));
let lastMinute = -1;

function tick() {
  const left = Math.max(0, target - Date.now());   // recomputed each tick, so no drift
  const sec = Math.floor(left / 1000);
  set('d', Math.floor(sec / 86400));
  set('h', Math.floor((sec % 86400) / 3600));
  set('m', Math.floor((sec % 3600) / 60));
  set('s', sec % 60);

  const minute = Math.floor(sec / 60);
  if (minute !== lastMinute) {                      // announce once a minute only
    lastMinute = minute;
    document.getElementById('cd-live').textContent = `${Math.floor(sec / 86400)} days ${Math.floor((sec % 86400) / 3600)} hours left`;
  }
  if (left === 0) {
    clearInterval(timer);
    document.getElementById('launch').classList.add('hidden');
    document.getElementById('cd-done').classList.remove('hidden');
  }
}
const timer = setInterval(tick, 1000);
tick();