:root {
  color-scheme: light dark;
  --accent: #2f6bff;
  --paper: #f2f2f7;
  --surface: #ffffff;
  --ink: #111113;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--paper);
  color: var(--ink);
}
main { width: min(760px, calc(100% - 40px)); margin: 0 auto; padding: 64px 0 80px; }
header { border-top: 8px solid var(--accent); padding-top: 28px; }
h1, h2 { line-height: 1.15; }
h1 { font-size: clamp(2.7rem, 9vw, 5.2rem); margin: 0; letter-spacing: -.055em; }
h2 { margin-top: 2.5rem; }
.mark { color: var(--accent); }
.lead { font-size: 1.2rem; max-width: 620px; }
.card { background: var(--surface); border: 1px solid #d9d9df; border-radius: 20px; padding: 24px; margin: 24px 0; }
a { color: #2459d3; text-underline-offset: 3px; }
nav { display: flex; flex-wrap: wrap; gap: 16px; margin: 28px 0; }
small { color: #53606f; }
code { overflow-wrap: anywhere; }
@media (prefers-color-scheme: dark) {
  :root { --paper: #000000; --surface: #1c1c1e; --ink: #f5f5f7; }
  .card { border-color: #38383a; }
  a { color: #7da2ff; }
  small { color: #aeb8c4; }
}