:root {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #e2e8f0;
  --accent: #38bdf8;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  display: grid;
  place-items: center;
  min-height: 100vh;
}

.card {
  background: var(--card);
  padding: 3rem;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

h1 { color: var(--accent); margin-bottom: 1rem; }

button {
  background: var(--accent);
  color: #0f172a;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: bold;
  cursor: pointer;
  margin: 1rem 0;
}

button:hover { filter: brightness(1.15); }

pre {
  background: #0f172a;
  padding: 1rem;
  border-radius: 8px;
  min-height: 1.5em;
}

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