:root {
  --bg: #0f172a;
  --card: #1e293b;
  --accent: #38bdf8;
  --text: #f1f5f9;
  --muted: #94a3b8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: radial-gradient(circle at top, #1e293b, var(--bg));
  color: var(--text);
}

.card {
  text-align: center;
  padding: 3rem 3.5rem;
  background: var(--card);
  border-radius: 1rem;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}

h1 {
  margin: 0 0 0.5rem;
  font-size: 2.5rem;
}

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

button {
  border: none;
  border-radius: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: #0f172a;
  background: var(--accent);
  cursor: pointer;
  transition: transform 0.1s ease, filter 0.2s ease;
}

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

button:active {
  transform: scale(0.96);
}