:root {
  --bg: #0f172a;
  --bg-alt: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 1.5rem;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  transition: background-color 0.4s ease;
}

.card {
  width: 100%;
  max-width: 32rem;
  padding: 2.5rem 2rem;
  text-align: center;
  background: var(--bg-alt);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: var(--radius);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.35);
}

h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(2rem, 6vw, 3rem);
  color: var(--accent);
}

.subtitle {
  margin: 0 0 1.5rem;
  font-size: 1.1rem;
  color: var(--muted);
}

.build,
.clock {
  margin: 0.25rem 0;
  font-size: 0.9rem;
  color: var(--muted);
}

button {
  margin-top: 1.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  color: var(--bg);
  cursor: pointer;
  background: var(--accent);
  border: none;
  border-radius: 999px;
  transition: transform 0.15s ease, filter 0.15s ease;
}

button:hover {
  filter: brightness(1.1);
}

button:active {
  transform: scale(0.97);
}

@media (max-width: 480px) {
  .card {
    padding: 1.75rem 1.25rem;
  }
}