:root {
  color-scheme: light dark;
  --background: #0d1117;
  --surface: #161b22;
  --text: #e6edf3;
  --muted: #9da7b3;
  --accent: #79c0ff;
  --border: #30363d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font: 17px/1.65 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

main {
  width: min(760px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 5rem 0 3rem;
}

h1, h2 { line-height: 1.2; }
h1 { margin: .25rem 0 1rem; font-size: clamp(2.2rem, 6vw, 4rem); }
h2 { margin-top: 0; font-size: 1.35rem; }

.eyebrow {
  color: var(--accent);
  font-size: .85rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.lede { color: var(--muted); font-size: 1.2rem; }

section {
  margin: 2rem 0;
  padding: 1.4rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
}

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

footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

@media (prefers-color-scheme: light) {
  :root {
    --background: #f6f8fa;
    --surface: #ffffff;
    --text: #1f2328;
    --muted: #59636e;
    --accent: #0969da;
    --border: #d0d7de;
  }
}