:root {
  color-scheme: dark;
  --paper: #10151b;
  --panel: #18212b;
  --ink: #edf3f6;
  --muted: #a7b5be;
  --accent: #66d0c2;
  --rule: #2b3945;
}

* { box-sizing: border-box; }

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

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

.site-header,
main,
footer {
  width: min(760px, calc(100% - 2rem));
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--rule);
}

.brand { color: var(--ink); font-weight: 750; text-decoration: none; }
nav { display: flex; gap: 1rem; }
nav a { text-decoration: none; }
main { padding: clamp(3rem, 9vw, 7rem) 0; }

.card {
  padding: clamp(1.5rem, 5vw, 3rem);
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 1rem;
}

h1 { margin: 0 0 1rem; font-size: clamp(2.25rem, 8vw, 4.5rem); line-height: 1; }
.eyebrow { margin: 0 0 .8rem; color: var(--accent); font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
code { padding: .1em .35em; background: #0c1116; border-radius: .25rem; }
footer { padding: 1rem 0 2.5rem; border-top: 1px solid var(--rule); color: var(--muted); font-size: .85rem; }

@media (max-width: 520px) {
  .site-header { align-items: flex-start; flex-direction: column; gap: .75rem; }
}