:root {
  --bg: #f8f9fb;
  --surface: #ffffff;
  --ink: #16222f;
  --muted: #5a6b7d;
  --line: #dce4ec;
  --accent: #14647d;
  --accent-ink: #ffffff;
  --soft: #e7f2f5;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e151c;
    --surface: #151f29;
    --ink: #e6edf3;
    --muted: #92a3b4;
    --line: #263442;
    --accent: #58b7d4;
    --accent-ink: #0e151c;
    --soft: #17303a;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 24px; }
header.site {
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 0; gap: 12px; flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 19px; color: var(--ink); text-decoration: none; }
.brand .mark {
  background: var(--accent); color: var(--accent-ink);
  font-size: 11px; font-weight: 800; letter-spacing: 0.02em;
  border-radius: 8px; padding: 6px 8px;
}
nav.site a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 15px; }
nav.site a:hover { color: var(--ink); }
main { padding: 24px 0 64px; }
h1 { font-size: clamp(30px, 5vw, 40px); line-height: 1.15; letter-spacing: -0.015em; margin: 24px 0 10px; }
.updated { color: var(--muted); font-size: 14.5px; margin: 0 0 28px; }
h2 { font-size: 21px; margin: 36px 0 10px; letter-spacing: -0.01em; }
h3 { font-size: 17px; margin: 24px 0 8px; }
p, li { color: var(--muted); }
p strong, li strong { color: var(--ink); }
a { color: var(--accent); }
ul { padding-left: 22px; }
.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: 12px; padding: 20px 22px; margin: 18px 0;
}
.card p:first-child { margin-top: 0; }
.card p:last-child { margin-bottom: 0; }
footer.site {
  border-top: 1px solid var(--line);
  padding: 24px 0 48px;
  font-size: 14px; color: var(--muted);
}
footer.site a { color: var(--muted); }