:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #4338ca;
  --accent-hover: #3730a3;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111111;
    --fg: #f5f5f5;
    --muted: #999;
    --accent: #818cf8;
    --accent-hover: #a5b4fc;
  }
}
* { box-sizing: border-box; }
html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  min-height: 100vh;
  display: grid;
  place-items: center;
}
.card {
  max-width: 420px;
  padding: 32px;
  text-align: center;
}
h1 { font-size: 28px; margin: 0 0 16px; }
p { font-size: 16px; margin: 0 0 16px; color: var(--muted); }
.small { font-size: 13px; }
button, a#download-link {
  display: inline-block;
  padding: 10px 18px;
  margin: 4px;
  font-size: 14px;
  border-radius: 8px;
  text-decoration: none;
  cursor: pointer;
  border: 0;
}
button {
  background: var(--accent);
  color: white;
}
button:hover { background: var(--accent-hover); }
a#download-link {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}