:root {
  --bg: #f7f8fa;
  --fg: #18202e;
  --muted: #5a6475;
  --card: #ffffff;
  --line: #e2e6ec;
  --accent: #1f6feb;
  --code-bg: #0f1724;
  --code-fg: #e6edf3;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117;
    --fg: #e6edf3;
    --muted: #9aa5b4;
    --card: #161b22;
    --line: #2a313c;
    --accent: #58a6ff;
    --code-bg: #010409;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--fg);
}

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

header,
main,
footer {
  max-width: 46rem;
  margin: 0 auto;
  padding: 0 1rem;
}

header {
  padding-top: 3rem;
}

nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.95rem;
  margin-bottom: 2.5rem;
}

h1 {
  font-size: clamp(2rem, 6vw, 2.75rem);
  line-height: 1.15;
  margin: 0 0 1rem;
}

.lead {
  font-size: 1.15rem;
  color: var(--muted);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.1rem;
}

.card strong {
  display: block;
  margin-bottom: 0.25rem;
}

.card span {
  color: var(--muted);
  font-size: 0.95rem;
}

pre {
  background: var(--code-bg);
  color: var(--code-fg);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  font-size: 0.9rem;
  line-height: 1.5;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.button {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 0.6rem 1.1rem;
  border-radius: 8px;
  font-weight: 600;
  margin: 0.25rem 0.5rem 0.25rem 0;
}

.button.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

footer {
  color: var(--muted);
  font-size: 0.9rem;
  padding-top: 2rem;
  padding-bottom: 3rem;
  border-top: 1px solid var(--line);
  margin-top: 3rem;
}