:root {
  --brand: #2e5e7e;
  --ink: #1a1d20;
  --muted: #5a6166;
  --surface: #ffffff;
  --bg: #f7f8fa;
  --border: #e2e6ea;
  --warn-bg: #fff4d6;
  --warn-border: #f0c67a;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e7ebef;
    --muted: #9ca3a8;
    --surface: #15181b;
    --bg: #0e1013;
    --border: #2b3035;
    --warn-bg: #3b2e0a;
    --warn-border: #6a541d;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
}

header.site {
  background: var(--brand);
  color: #fff;
  padding: 20px 24px;
}
header.site a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  letter-spacing: 0.2px;
}
header.site nav {
  margin-top: 4px;
  font-size: 14px;
  opacity: 0.85;
}
header.site nav a { margin-right: 14px; opacity: 0.9; }
header.site nav a:hover { opacity: 1; text-decoration: underline; }

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 24px 80px;
  background: var(--surface);
}

@media (min-width: 760px) {
  main { margin-top: 24px; border-radius: 8px; border: 1px solid var(--border); }
}

h1 {
  font-size: 28px;
  margin: 0 0 8px;
  color: var(--brand);
}
h2 {
  font-size: 20px;
  margin: 32px 0 8px;
  padding-top: 4px;
}
h3 { font-size: 17px; margin: 24px 0 6px; }
p { margin: 0 0 12px; }
ul { padding-left: 22px; margin: 8px 0 16px; }
li { margin: 4px 0; }
strong { color: var(--ink); }
a { color: var(--brand); }
code, kbd {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 0.92em;
}

.meta {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 24px;
}

.note {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  padding: 12px 14px;
  border-radius: 6px;
  margin: 16px 0 24px;
  font-size: 15px;
}

footer.site {
  text-align: center;
  padding: 32px 24px;
  color: var(--muted);
  font-size: 14px;
}
footer.site a { color: var(--muted); }