:root {
  --text: #1c1f24;
  --muted: #6b7280;
  --bg: #fbfaf8;
  --panel: #ffffff;
  --line: #e3e0da;
  --accent: #1f4e79;
  --accent-soft: #e8eff5;
  --maxw: 860px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* Header / nav */
.sitehead {
  background: var(--accent);
  color: #fff;
  border-bottom: 3px solid #14324d;
}
.sitehead .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 24px; padding-top: 14px; padding-bottom: 14px; }
.brand { color: #fff; font-weight: 700; text-decoration: none; font-size: 1.05rem; letter-spacing: .2px; }
.topnav { display: flex; flex-wrap: wrap; gap: 4px 14px; }
.topnav a { color: #cfe0ee; text-decoration: none; font-size: .95rem; padding: 2px 0; }
.topnav a:hover { color: #fff; text-decoration: underline; }

/* Main */
main.wrap { padding-top: 28px; padding-bottom: 40px; }
h1 { font-size: 1.9rem; line-height: 1.25; margin: 0 0 6px; border-bottom: 2px solid var(--line); padding-bottom: 10px; }
h2 { font-size: 1.25rem; margin: 0 0 10px; }
h2[ id ], .group-title { margin-top: 36px; border-top: 2px solid var(--accent); padding-top: 10px; }
h3.subtle { font-size: .95rem; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin: 18px 0 6px; }
p.lead { font-size: 1.05rem; color: #333; margin: 10px 0 6px; }
p.meta { color: var(--muted); font-size: .92rem; margin: 4px 0 8px; }

/* Cards on index */
.cards { display: grid; grid-template-columns: 1fr; gap: 16px; margin: 22px 0; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 18px 20px; }
.card h2 { margin-top: 0; }
.card h2 a { color: var(--accent); text-decoration: none; }
.card h2 a:hover { text-decoration: underline; }
.card p { margin: 6px 0; }
code { background: #f0ede7; border: 1px solid var(--line); border-radius: 4px; padding: 0 4px; font-size: .88em; }

/* Table of contents */
nav.toc { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 14px 20px; margin: 14px 0 8px; }
nav.toc ul { columns: 2; column-gap: 32px; margin: 0; padding-left: 18px; list-style: square; }
nav.toc a { color: var(--accent); text-decoration: none; }
nav.toc a:hover { text-decoration: underline; }
@media (max-width: 560px) { nav.toc ul { columns: 1; } }

/* Sections */
section { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 18px 22px; margin: 18px 0; scroll-margin-top: 18px; }
section h2 { color: var(--accent); }
h2 .count { color: var(--muted); font-weight: 400; font-size: .9rem; }
section ul { margin: 6px 0 0; padding-left: 22px; }
section li { margin: 6px 0; }

.muted { color: var(--muted); }

/* Footer */
.sitefoot { border-top: 1px solid var(--line); color: var(--muted); font-size: .88rem; padding: 16px 0; margin-top: 30px; }