:root {
  --bg: #fafafa;
  --fg: #111;
  --muted: #555;
  --accent: #2563eb;
  --accent-fg: #fff;
  --border: #e5e5e5;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0a0a;
    --fg: #f5f5f5;
    --muted: #a0a0a0;
    --accent: #3b82f6;
    --accent-fg: #fff;
    --border: #262626;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
}

body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1.5rem;
}

main {
  width: 100%;
  max-width: 32rem;
  text-align: center;
}

h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.03em;
}

.tagline {
  color: var(--muted);
  font-size: 1.0625rem;
  margin: 0 0 2.5rem;
}

nav {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  align-items: center;
}

a.primary {
  display: inline-block;
  padding: 0.875rem 1.75rem;
  background: var(--accent);
  color: var(--accent-fg);
  text-decoration: none;
  border-radius: 0.5rem;
  font-weight: 500;
  transition: opacity 0.15s ease;
}

a.primary:hover {
  opacity: 0.9;
}

a.primary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}