/* The Agent Reliability Handbook - handbook / field-guide style.
   Deliberately distinct from the card-grid sibling site:
   sticky left contents nav, single serif-headed reading column,
   warm paper palette. */

:root {
  --paper: #f7f4ee;
  --surface: #fffdf9;
  --sidebar: #efeae0;
  --ink: #23201b;
  --muted: #6d665a;
  --faint: #98917f;
  --rule: #e2daca;
  --accent: #b4531f;      /* terracotta */
  --accent-soft: #f3e2d5;
  --green: #4b6b52;       /* secondary, for checkmarks */
  --code-bg: #efe9dd;
  --sidebar-w: 300px;
  --measure: 720px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 18px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, .display {
  font-family: "Fraunces", Georgia, "Times New Roman", serif;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---- Layout ---- */
.layout { display: grid; grid-template-columns: var(--sidebar-w) 1fr; }

.sidebar {
  background: var(--sidebar);
  border-right: 1px solid var(--rule);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 32px 26px 48px;
}
.sidebar .mast { display: block; margin-bottom: 8px; }
.sidebar .mast .kicker {
  font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--accent); font-weight: 700;
}
.sidebar .mast .title {
  font-family: "Fraunces", Georgia, serif; font-size: 25px; color: var(--ink);
  display: block; line-height: 1.15; margin-top: 4px;
}
.sidebar .mast:hover { text-decoration: none; }
.sidebar .tagline { color: var(--muted); font-size: 13.5px; margin: 10px 0 18px; }

/* Search */
.hb-search {
  width: 100%;
  background: #fffdf9;
  border: 1px solid var(--rule);
  color: var(--ink);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 14px;
  font-family: "Inter", sans-serif;
  margin: 0 0 22px;
}
.hb-search::placeholder { color: var(--faint); }
.hb-search:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }

.search-results {
  position: fixed; z-index: 100;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 10px;
  box-shadow: 0 14px 34px rgba(35, 32, 27, 0.16);
  overflow: hidden; max-height: 62vh; overflow-y: auto;
}
.search-results a {
  display: flex; justify-content: space-between; gap: 14px; align-items: baseline;
  padding: 11px 14px; color: var(--ink); border-bottom: 1px solid var(--rule);
}
.search-results a:last-child { border-bottom: none; }
.search-results a:hover { background: var(--paper); text-decoration: none; }
.search-results .sr-t { font-size: 14px; font-weight: 500; }
.search-results .sr-s { font-size: 12px; color: var(--faint); white-space: nowrap; }
.search-results .sr-empty { padding: 12px 14px; color: var(--faint); font-size: 14px; }

.nav-group { margin-bottom: 22px; }
.nav-group h5 {
  font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--faint); margin: 0 0 8px; font-weight: 700;
}
.nav-group ol { list-style: none; margin: 0; padding: 0; counter-reset: n; }
.nav-group li { margin: 0; }
.nav-group a {
  display: block; color: var(--ink); font-size: 14.5px;
  padding: 5px 10px 5px 12px; border-radius: 6px; border-left: 2px solid transparent;
}
.nav-group a:hover { background: rgba(180,83,31,0.08); text-decoration: none; }
.nav-group a.active {
  background: var(--accent-soft); border-left-color: var(--accent);
  color: var(--accent); font-weight: 600;
}

/* ---- Content ---- */
.content { padding: 64px 56px 96px; }
.reading { max-width: var(--measure); margin: 0 auto; }

.eyebrow {
  font-size: 12px; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--accent); font-weight: 700; margin-bottom: 14px;
}
.content h1 { font-size: 42px; margin: 0 0 18px; }
.lead { font-size: 21px; color: #3c372e; line-height: 1.55; margin: 0 0 36px; }

.content h2 { font-size: 26px; margin: 44px 0 14px; }
.content p { margin: 0 0 18px; }
.content ul, .content ol { margin: 0 0 20px; padding-left: 24px; }
.content li { margin-bottom: 9px; }
.content strong { font-weight: 600; }

code {
  background: var(--code-bg); padding: 2px 6px; border-radius: 4px;
  font-family: "SF Mono", Menlo, Consolas, monospace; font-size: 15px;
}

/* Dark code blocks (sit on the warm paper background) */
pre {
  position: relative;
  background: #221d18;
  border: 1px solid #3a3128;
  border-radius: 10px;
  padding: 18px 20px;
  margin: 24px 0;
  overflow-x: auto;
}
pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  color: #ece5d8;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13.5px;
  line-height: 1.6;
  display: block;
  white-space: pre;
}
pre .lang {
  position: absolute;
  top: 10px;
  right: 14px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #9c8f7c;
}

/* Principle / callout */
.principle {
  border-left: 3px solid var(--accent);
  background: var(--surface);
  padding: 18px 22px; margin: 28px 0; border-radius: 0 8px 8px 0;
  font-family: "Fraunces", Georgia, serif; font-size: 20px; line-height: 1.4;
  color: #362f24;
}

/* Key takeaways checklist */
.takeaways {
  background: var(--surface); border: 1px solid var(--rule);
  border-radius: 12px; padding: 24px 26px; margin: 40px 0;
}
.takeaways h3 { font-size: 15px; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--muted); margin: 0 0 14px; font-family: "Inter", sans-serif; font-weight: 700; }
.takeaways ul { list-style: none; padding: 0; margin: 0; }
.takeaways li { position: relative; padding-left: 30px; margin-bottom: 11px; }
.takeaways li::before {
  content: ""; position: absolute; left: 0; top: 4px;
  width: 16px; height: 16px; border-radius: 4px; background: var(--green);
  box-shadow: inset 0 0 0 2px var(--green);
}
.takeaways li::after {
  content: ""; position: absolute; left: 5px; top: 7px;
  width: 4px; height: 8px; border: solid #fff; border-width: 0 2px 2px 0;
  transform: rotate(40deg);
}

/* Further reading */
.further { margin: 44px 0 8px; border-top: 1px solid var(--rule); padding-top: 24px; }
.further h3 { font-size: 15px; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--muted); margin: 0 0 12px; font-family: "Inter", sans-serif; font-weight: 700; }
.further ul { list-style: none; padding: 0; margin: 0; }
.further li { margin-bottom: 18px; }
.further li a { font-weight: 600; }
.further .src { color: var(--faint); font-size: 13px; margin-left: 6px; }
.further .fr-desc { display: block; color: var(--muted); font-size: 15px; line-height: 1.5; margin-top: 3px; }

/* Prev / next pager */
.pager { display: flex; justify-content: space-between; gap: 16px; margin-top: 56px;
  border-top: 1px solid var(--rule); padding-top: 24px; }
.pager a { display: block; max-width: 48%; }
.pager .dir { font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--faint); }
.pager .t { font-family: "Fraunces", Georgia, serif; font-size: 17px; color: var(--ink); }
.pager a:hover { text-decoration: none; }
.pager a:hover .t { color: var(--accent); }
.pager .next { text-align: right; margin-left: auto; }

/* Homepage contents */
.home-hero { margin-bottom: 12px; }
.home-hero h1 { font-size: 52px; margin: 0 0 20px; }
.toc-section { margin: 40px 0; }
.toc-section h2 { font-size: 24px; margin: 0 0 4px; }
.toc-section .sec-note { color: var(--muted); margin: 0 0 18px; font-size: 16px; }
.toc-list { display: grid; gap: 2px; }
.toc-list a {
  display: flex; gap: 14px; align-items: baseline; padding: 12px 14px;
  border-radius: 8px; color: var(--ink); border: 1px solid transparent;
}
.toc-list a:hover { background: var(--surface); border-color: var(--rule); text-decoration: none; }
.toc-list .num { font-family: "Fraunces", Georgia, serif; color: var(--accent); font-size: 15px; min-width: 26px; }
.toc-list .tl { font-weight: 600; }
.toc-list .td { color: var(--muted); font-size: 15px; }

/* Mobile */
.navtoggle { display: none; }
@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; }
  .sidebar .nav-wrap { display: none; }
  .sidebar.open .nav-wrap { display: block; margin-top: 18px; }
  .navtoggle {
    display: inline-block; margin-top: 14px; background: var(--accent); color: #fff;
    border: none; padding: 8px 14px; border-radius: 6px; font-size: 14px; cursor: pointer;
  }
  .content { padding: 40px 22px 72px; }
  .content h1 { font-size: 33px; }
  .home-hero h1 { font-size: 38px; }
}