:root {
  --bg: #0b0d10;
  --bg-soft: #12161b;
  --fg: #e8eaed;
  --muted: #8b949e;
  --accent: #5eead4;
  --border: #1f262e;
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(60% 60% at 50% 0%, rgba(94, 234, 212, 0.08), transparent 70%),
    var(--bg);
  color: var(--fg);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
  display: grid;
  place-items: center;
  padding: 2rem;
}

.wrap {
  width: 100%;
  max-width: 640px;
  text-align: center;
}

.mark {
  width: 56px;
  height: 56px;
  margin: 0 auto 1.5rem;
  border: 1px solid var(--border);
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--bg-soft);
}

.dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 20px 2px rgba(94, 234, 212, 0.6);
}

h1 {
  margin: 0;
  font-size: clamp(2.5rem, 8vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.accent { color: var(--accent); }

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f8fa;
    --bg-soft: #ffffff;
    --fg: #1a1f24;
    --muted: #5b6570;
    --accent: #0d9488;
    --border: #e3e7ec;
  }
  .dot { box-shadow: 0 0 20px 2px rgba(13, 148, 136, 0.35); }
}