:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --text: #1c1d1f;
  --muted: #5b5f66;
  --line: #e2e2de;
  --accent: #1f5f8b;
  --accent-soft: #e8f0f6;
  --radius: 10px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141517;
    --surface: #1c1e21;
    --text: #e8e9eb;
    --muted: #a3a8b0;
    --line: #2e3136;
    --accent: #7db6dc;
    --accent-soft: #1d2a34;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--accent); text-underline-offset: 2px; }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

header.site {
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
header.site .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; min-height: 60px; flex-wrap: wrap;
}
.brand { font-weight: 650; letter-spacing: .01em; color: var(--text); text-decoration: none; }
nav.site a { margin-left: 18px; font-size: .95rem; }
nav.site a:first-child { margin-left: 0; }
nav.site a[aria-current="page"] { color: var(--text); text-decoration: none; font-weight: 600; }

main { padding: 40px 0 56px; }
h1 { font-size: clamp(1.7rem, 4.5vw, 2.2rem); line-height: 1.2; margin: 0 0 12px; letter-spacing: -.01em; }
h2 { font-size: 1.2rem; margin: 36px 0 8px; }
h3 { font-size: 1rem; margin: 22px 0 4px; }
p, li { color: var(--text); }
.lead { font-size: 1.1rem; color: var(--muted); margin: 0 0 28px; }
.meta { color: var(--muted); font-size: .92rem; margin: 0 0 28px; }
ul { padding-left: 1.25rem; }
li { margin: 4px 0; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin: 20px 0;
}
.card h2 { margin-top: 0; }
.note {
  background: var(--accent-soft);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin: 20px 0;
}
.grid { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 640px) { .grid { grid-template-columns: 1fr 1fr; } }
.grid .card { margin: 0; }
.grid .card h2 { font-size: 1.05rem; }
code { font: .92em ui-monospace, SFMono-Regular, Menlo, monospace; }

footer.site {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .9rem;
  padding: 22px 0 32px;
}
footer.site a { margin-right: 16px; }