:root {
  color-scheme: light dark;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  background: #f4f7fb;
  color: #0a1228;
}

body { margin: 0; }
main { max-width: 48rem; margin: 0 auto; padding: 3rem 1.25rem 5rem; }
header { padding: 2rem 0; }
h1 { font-size: clamp(2.2rem, 7vw, 3.4rem); line-height: 1.05; margin: .4rem 0 1rem; }
h2 { margin-top: 2.2rem; line-height: 1.2; }
a { color: #0e7c86; }
nav { display: grid; gap: .8rem; }
nav a { display: block; padding: 1rem 1.2rem; border: 1px solid #b7c9d6; border-radius: .8rem; background: #fff; text-decoration: none; font-weight: 600; }
.eyebrow { text-transform: uppercase; letter-spacing: .14em; font-weight: 700; color: #3d5a73; }
.updated { color: #56635a; }
.back { display: inline-block; margin-bottom: 2rem; }

@media (prefers-color-scheme: dark) {
  :root { background: #0a1228; color: #e8f4ff; }
  a { color: #7fe0e8; }
  nav a { background: #122036; border-color: #2a4660; }
  .eyebrow, .updated { color: #9bb8cc; }
}