/* =========================================================
   MANAGED AGENT COMMAND — Dual-brand stylesheet
   AUTOPILOT (default) / OPERATOR (toggle)
   ========================================================= */

:root {
  /* AUTOPILOT (default) */
  --mac-primary: #FF3B5C;
  --mac-secondary: #FFDE59;
  --mac-accent: #1A1A2E;
  --mac-bg: #FFFFFF;
  --mac-surface: #FFF6F7;
  --mac-text: #1A1A2E;

  --page-bg: #FBFAF8;
  --card-bg: #FFFFFF;
  --card-border: rgba(26,26,46,0.08);
  --muted: #6B6B7A;
  --rule: rgba(26,26,46,0.10);
  --callout-try-bg: #FFF8E5;
  --callout-try-border: #FFDE59;
  --callout-pit-bg: #FFE9ED;
  --callout-pit-border: #FF3B5C;
  --callout-kit-bg: #FFF6F7;
  --callout-kit-border: #1A1A2E;
  --code-bg: #1A1A2E;
  --code-text: #F6F6F8;
  --inline-code-bg: rgba(26,26,46,0.06);
  --inline-code-text: #1A1A2E;
  --font-display: 'Space Grotesk', ui-sans-serif, system-ui, sans-serif;
  --font-body: 'DM Sans', ui-sans-serif, system-ui, sans-serif;
  --font-mono: ui-monospace, 'JetBrains Mono', 'Fira Code', Menlo, monospace;

  --shadow-sm: 0 1px 2px rgba(26,26,46,0.05);
  --shadow-md: 0 4px 16px rgba(26,26,46,0.08);
  --shadow-lg: 0 16px 48px rgba(26,26,46,0.12);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --container: 1200px;
  --prose: 680px;
}

:root[data-theme="operator"] {
  --mac-primary: #C8A96E;
  --mac-secondary: #4A90D9;
  --mac-accent: #C8A96E;
  --mac-bg: #0A0A0F;
  --mac-surface: #111118;
  --mac-text: #E8E8EC;

  --page-bg: #060609;
  --card-bg: #0D0D14;
  --card-border: rgba(200,169,110,0.14);
  --muted: #8A8A95;
  --rule: rgba(200,169,110,0.16);
  --callout-try-bg: rgba(74,144,217,0.08);
  --callout-try-border: #4A90D9;
  --callout-pit-bg: rgba(200,78,78,0.08);
  --callout-pit-border: #C8696E;
  --callout-kit-bg: rgba(200,169,110,0.06);
  --callout-kit-border: #C8A96E;
  --code-bg: #0D0D14;
  --code-text: #E8E8EC;
  --inline-code-bg: rgba(200,169,110,0.10);
  --inline-code-text: #E8E8EC;
  --font-display: 'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', ui-sans-serif, system-ui, sans-serif;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.40);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.50);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.60);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}
body { overflow-x: hidden; }

body {
  font-family: var(--font-body);
  color: var(--mac-text);
  background: var(--page-bg);
  line-height: 1.7;
  font-size: 17px;
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.35s ease, color 0.35s ease;
}

img, svg { display: block; max-width: 100%; }

a {
  color: var(--mac-text);
  text-decoration-color: var(--mac-primary);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}
a:hover { color: var(--mac-primary); }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--mac-text);
}

:root[data-theme="operator"] h1,
:root[data-theme="operator"] h2,
:root[data-theme="operator"] h3,
:root[data-theme="operator"] h4 {
  font-weight: 700;
  letter-spacing: -0.01em;
}

/* ---------- Top reading progress bar ---------- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--mac-primary), var(--mac-secondary));
  z-index: 200;
  transition: width 0.1s linear;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--page-bg) 85%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--rule);
  transition: background-color 0.35s ease, border-color 0.35s ease;
}

.site-header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--mac-text);
}
.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  line-height: 1.1;
  white-space: nowrap;
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.55;
  white-space: nowrap;
}
.brand > span > br + .brand-sub { display: inline-block; }
@media (max-width: 520px) {
  .brand > span > br { display: none; }
  .brand-sub { display: none; }
  .brand-name { font-size: 14px; }
  .site-header-inner { padding: 12px 16px; gap: 10px; }
  .theme-toggle button { font-size: 9px; padding: 5px 8px; letter-spacing: 0.1em; }
  .brand-mark { width: 22px; height: 22px; }
}

.nav-primary {
  display: none;
  gap: 24px;
  font-size: 14px;
  font-weight: 500;
}
@media (min-width: 900px) { .nav-primary { display: flex; } }
.nav-primary a {
  text-decoration: none;
  opacity: 0.75;
}
.nav-primary a:hover,
.nav-primary a.is-active {
  opacity: 1;
  color: var(--mac-primary);
}

.theme-toggle {
  display: inline-flex;
  padding: 3px;
  border-radius: 999px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  box-shadow: var(--shadow-sm);
}
.theme-toggle button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--mac-text);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  font-weight: 600;
  padding: 6px 11px;
  border-radius: 999px;
  cursor: pointer;
  opacity: 0.55;
  transition: all 0.25s ease;
}
.theme-toggle button.is-on {
  background: var(--mac-primary);
  color: var(--mac-bg);
  opacity: 1;
}
:root[data-theme="operator"] .theme-toggle button.is-on {
  background: var(--mac-primary);
  color: var(--mac-bg);
}

.menu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: 8px;
  background: transparent;
  border: 1px solid var(--card-border);
  color: var(--mac-text);
  cursor: pointer;
}
@media (min-width: 1024px) { .menu-btn.chapter-menu { display: none; } }

/* ---------- Layout shells ---------- */
.container { max-width: var(--container); margin: 0 auto; padding: 0 28px; }
@media (max-width: 560px) { .container { padding: 0 18px; } }

section { padding: 88px 0; }
@media (max-width: 720px) { section { padding: 64px 0; } }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mac-primary);
  display: inline-block;
  margin-bottom: 16px;
}

/* ---------- Homepage hero ---------- */
.hero {
  padding: 80px 0 40px;
  border-bottom: 1px solid var(--rule);
  position: relative;
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}
@media (min-width: 960px) {
  .hero-grid { grid-template-columns: 1.1fr 0.9fr; gap: 60px; }
}

.hero h1 {
  font-size: clamp(40px, 6vw, 76px);
  line-height: 1.02;
  letter-spacing: -0.035em;
}
:root[data-theme="operator"] .hero h1 {
  letter-spacing: -0.015em;
  font-style: italic;
}

.hero-tag {
  font-size: 18px;
  color: var(--muted);
  margin-top: 20px;
  max-width: 520px;
}

.tagline-swap .t-autopilot { display: inline; }
.tagline-swap .t-operator { display: none; }
:root[data-theme="operator"] .tagline-swap .t-autopilot { display: none; }
:root[data-theme="operator"] .tagline-swap .t-operator { display: inline; }

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 22px;
  border-radius: 999px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  cursor: pointer;
}
.btn-primary {
  background: var(--mac-primary);
  color: var(--mac-bg);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  color: var(--mac-bg);
}
.btn-ghost {
  background: transparent;
  color: var(--mac-text);
  border-color: var(--card-border);
}
.btn-ghost:hover {
  border-color: var(--mac-primary);
  color: var(--mac-primary);
}

.hero-visual {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.hero-visual svg { width: 100%; height: auto; }

/* ---------- Parts ---------- */
.parts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.part-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.part-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--mac-primary); }
.part-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--mac-primary);
  letter-spacing: 0.1em;
}
.part-card h3 {
  font-size: 22px;
  margin: 10px 0 8px;
}
.part-card p { color: var(--muted); font-size: 15px; }

/* ---------- TOC Chapters grid ---------- */
.toc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.toc-card {
  display: block;
  text-decoration: none;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 22px 22px;
  color: var(--mac-text);
  transition: all 0.2s ease;
  position: relative;
}
.toc-card:hover {
  border-color: var(--mac-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: var(--mac-text);
}
.toc-card .ch-num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
}
.toc-card .ch-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.25;
  margin-top: 6px;
  letter-spacing: -0.01em;
}
.toc-card .ch-part {
  display: inline-block;
  margin-top: 12px;
  font-size: 11px;
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mac-primary);
}

/* ---------- Toolkit preview grid ---------- */
.toolkit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
}
.toolkit-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 22px;
  transition: all 0.2s ease;
  text-decoration: none;
  color: var(--mac-text);
  display: block;
}
.toolkit-card:hover {
  border-color: var(--mac-primary);
  box-shadow: var(--shadow-md);
  color: var(--mac-text);
}
.toolkit-card .kit-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--mac-primary);
  letter-spacing: 0.14em;
}
.toolkit-card h3 {
  font-size: 17px;
  margin-top: 8px;
}
.toolkit-card p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 8px;
}
.toolkit-card .dl {
  display: inline-block;
  margin-top: 14px;
  font-size: 12px;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--mac-primary);
}

/* ---------- Chapter layout (2 col: sidebar + prose) ---------- */
.chapter-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}
@media (min-width: 1024px) {
  .chapter-shell {
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 0;
  }
}
.chapter-main { min-width: 0; }

.chapter-sidebar {
  display: none;
  padding: 40px 24px 60px 28px;
  border-right: 1px solid var(--rule);
  position: sticky;
  top: 64px;
  align-self: start;
  max-height: calc(100vh - 64px);
  overflow-y: auto;
}
@media (min-width: 1024px) { .chapter-sidebar { display: block; } }

.chapter-sidebar .side-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 14px;
  display: block;
}

.chapter-sidebar ol {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 3px;
}
.chapter-sidebar li a {
  display: flex;
  gap: 10px;
  text-decoration: none;
  font-size: 13.5px;
  color: var(--mac-text);
  opacity: 0.65;
  padding: 7px 10px;
  border-radius: 7px;
  line-height: 1.35;
  transition: all 0.2s ease;
  border-left: 2px solid transparent;
}
.chapter-sidebar li a:hover { opacity: 1; background: var(--card-bg); color: var(--mac-primary); }
.chapter-sidebar li a.is-current {
  opacity: 1;
  font-weight: 600;
  color: var(--mac-primary);
  border-left-color: var(--mac-primary);
  background: var(--card-bg);
}
.chapter-sidebar .side-num {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--muted);
  width: 26px;
  flex-shrink: 0;
  padding-top: 2px;
}
.chapter-sidebar li a.is-current .side-num { color: var(--mac-primary); }

.chapter-sidebar .side-section {
  margin: 20px 0 10px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  padding-left: 10px;
}

/* Mobile drawer */
.sidebar-drawer {
  position: fixed;
  top: 0; left: -320px;
  width: 300px;
  max-width: 85vw;
  height: 100vh;
  background: var(--page-bg);
  border-right: 1px solid var(--rule);
  z-index: 150;
  padding: 80px 18px 32px;
  overflow-y: auto;
  transition: left 0.3s ease;
}
.sidebar-drawer.is-open { left: 0; }
.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  opacity: 0;
  pointer-events: none;
  z-index: 140;
  transition: opacity 0.3s ease;
}
.sidebar-backdrop.is-open { opacity: 1; pointer-events: auto; }

/* ---------- Chapter progress + content ---------- */
.chapter-main { padding: 28px 0 80px; }

.chapter-meta {
  max-width: var(--prose);
  margin: 0 auto 28px;
  padding: 0 28px;
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  flex-wrap: wrap;
}
.chapter-meta > span:last-child { flex: 1 1 auto; min-width: 0; }
@media (max-width: 720px) {
  .chapter-meta { padding: 0 18px; font-size: 10px; letter-spacing: 0.08em; }
}
.chapter-meta .pip {
  height: 6px;
  width: 6px;
  border-radius: 50%;
  background: var(--mac-primary);
  display: inline-block;
}

.prose {
  max-width: var(--prose);
  margin: 0 auto;
  padding: 0 28px;
}
@media (max-width: 720px) { .prose { padding: 0 18px; } }

.prose h1 {
  font-size: clamp(32px, 4.6vw, 48px);
  margin-bottom: 12px;
  letter-spacing: -0.03em;
}
:root[data-theme="operator"] .prose h1 { font-style: italic; }
.prose h2 {
  font-size: 28px;
  margin: 42px 0 14px;
}
/* Space after a hr -> next h2 should be tight (hr already provides the rule) */
.prose hr + h2 { margin-top: 8px; }
.prose h3 {
  font-size: 21px;
  margin: 32px 0 10px;
}
.prose h4 {
  font-size: 17px;
  margin: 22px 0 8px;
  font-family: var(--font-body);
}

.prose p {
  margin: 1em 0;
  color: var(--mac-text);
}
.prose > p:first-of-type {
  font-size: 19px;
  color: var(--muted);
}
.prose strong { color: var(--mac-text); font-weight: 700; }
:root[data-theme="operator"] .prose strong { color: var(--mac-primary); }

.prose ul, .prose ol {
  margin: 1em 0 1em 1.4em;
}
.prose li { margin: 0.35em 0; }

.prose blockquote {
  margin: 28px 0;
  padding: 4px 0 4px 22px;
  border-left: 3px solid var(--mac-primary);
  font-family: var(--font-display);
  font-size: 22px;
  line-height: 1.4;
  font-weight: 500;
  color: var(--mac-text);
}
:root[data-theme="operator"] .prose blockquote { font-style: italic; }

.prose code {
  font-family: var(--font-mono);
  background: var(--inline-code-bg);
  color: var(--inline-code-text);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88em;
}
.prose pre {
  background: var(--code-bg);
  color: var(--code-text);
  padding: 20px 22px;
  border-radius: var(--radius-md);
  overflow-x: auto;
  font-size: 13.5px;
  margin: 22px 0;
  line-height: 1.55;
  border: 1px solid var(--card-border);
}
.prose pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 48px 0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 14.5px;
}
.prose th, .prose td {
  border-bottom: 1px solid var(--rule);
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
}
.prose th {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 2px solid var(--mac-primary);
}
:root[data-theme="operator"] .prose th { font-style: italic; letter-spacing: 0; text-transform: none; font-size: 15px; }

.prose img, .prose svg { max-width: 100%; height: auto; }

/* ---------- Callouts ---------- */
.callout {
  margin: 32px 0;
  padding: 22px 24px;
  border-radius: var(--radius-md);
  border: 1px solid;
  border-left-width: 4px;
  background: var(--callout-kit-bg);
  border-color: var(--callout-kit-border);
}
.callout .callout-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  color: var(--mac-primary);
}
.callout.try {
  background: var(--callout-try-bg);
  border-color: var(--callout-try-border);
}
.callout.try .callout-label { color: var(--mac-accent); }
:root[data-theme="operator"] .callout.try .callout-label { color: var(--mac-secondary); }
.callout.pit {
  background: var(--callout-pit-bg);
  border-color: var(--callout-pit-border);
}
.callout.pit .callout-label { color: var(--mac-primary); }
:root[data-theme="operator"] .callout.pit .callout-label { color: #E8948F; }

/* ---------- Visual figure / diagram card ---------- */
.fig {
  margin: 40px 0;
  padding: 28px 24px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}
.fig svg { width: 100%; height: auto; }
.fig figcaption {
  font-style: italic;
  color: var(--muted);
  font-size: 13.5px;
  margin-top: 16px;
  padding-left: 14px;
  border-left: 2px solid var(--mac-primary);
}

.fig.placeholder {
  display: flex;
  gap: 18px;
  align-items: flex-start;
}
.fig.placeholder .fig-icon {
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border-radius: 10px;
  background: var(--mac-surface);
  border: 1px solid var(--mac-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--mac-primary);
}
.fig.placeholder figcaption {
  margin: 0;
  padding: 4px 0 0 0;
  border: 0;
  color: var(--muted);
  font-style: italic;
}
.fig.placeholder .fig-tag {
  display: block;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 10.5px;
  color: var(--mac-primary);
  margin-bottom: 4px;
  font-style: normal;
}

/* ---------- Prev / Next chapter nav ---------- */
.chapter-nav {
  max-width: var(--prose);
  margin: 64px auto 0;
  padding: 0 28px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
@media (max-width: 640px) { .chapter-nav { grid-template-columns: 1fr; } }
.chapter-nav a {
  display: block;
  text-decoration: none;
  padding: 20px 22px;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  background: var(--card-bg);
  transition: all 0.2s ease;
  color: var(--mac-text);
}
.chapter-nav a:hover { border-color: var(--mac-primary); transform: translateY(-2px); box-shadow: var(--shadow-sm); color: var(--mac-text); }
.chapter-nav .dir {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}
.chapter-nav .ch-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.3;
  margin-top: 4px;
}
.chapter-nav .next { text-align: right; }

/* ---------- Glossary ---------- */
.glossary-search {
  width: 100%;
  padding: 16px 20px;
  border: 1px solid var(--card-border);
  border-radius: 999px;
  background: var(--card-bg);
  color: var(--mac-text);
  font-family: var(--font-body);
  font-size: 16px;
  margin-bottom: 28px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.glossary-search:focus {
  outline: none;
  border-color: var(--mac-primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--mac-primary) 16%, transparent);
}

.term {
  padding: 22px 0;
  border-bottom: 1px solid var(--rule);
}
.term h3 {
  font-size: 21px;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}
.term.is-hidden { display: none; }

.glossary-empty {
  padding: 40px 0;
  text-align: center;
  color: var(--muted);
  display: none;
}
.glossary-empty.is-shown { display: block; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--rule);
  padding: 64px 0 40px;
  margin-top: 80px;
  background: var(--card-bg);
}
.site-footer .container {
  display: grid;
  gap: 32px;
  grid-template-columns: 1fr;
}
@media (min-width: 720px) {
  .site-footer .container { grid-template-columns: 1.5fr 1fr 1fr; }
}
.footer-brand p { color: var(--muted); font-size: 14px; margin-top: 14px; max-width: 380px; }
.site-footer h4 {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 600;
  margin-bottom: 14px;
}
.site-footer ul { list-style: none; display: flex; flex-direction: column; gap: 8px; font-size: 14px; }
.site-footer a { text-decoration: none; opacity: 0.75; color: var(--mac-text); }
.site-footer a:hover { opacity: 1; color: var(--mac-primary); }
.footer-fine {
  max-width: var(--container);
  margin: 40px auto 0;
  padding: 20px 28px 0;
  border-top: 1px solid var(--rule);
  font-size: 12px;
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  letter-spacing: 0.06em;
}

/* ---------- Theme-reactive accents on SVG ---------- */
.prose svg, .hero-visual svg, .fig svg {
  transition: filter 0.35s ease;
}

/* ---------- Utility ---------- */
.u-center { text-align: center; }
.u-section-head {
  display: grid;
  gap: 8px;
  margin-bottom: 40px;
  max-width: 720px;
}
.u-section-head h2 {
  font-size: clamp(30px, 4vw, 44px);
  letter-spacing: -0.025em;
  line-height: 1.1;
}
:root[data-theme="operator"] .u-section-head h2 { font-style: italic; }
.u-section-head p { color: var(--muted); max-width: 560px; font-size: 17px; }

.divider-rule {
  max-width: var(--container);
  margin: 0 auto;
  border-top: 1px solid var(--rule);
}