:root {
  --bg: #0a0a0f;
  --bg-2: #11121a;
  --bg-3: #161826;
  --fg: #f5f5f7;
  --muted: #8a8a96;
  --gold: #d4b48a;
  --gold-2: #e8c79b;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.14);
  --gold-bg: rgba(212, 180, 138, 0.08);
  --gold-border: rgba(212, 180, 138, 0.28);
  --radius: 16px;
  --radius-sm: 10px;
  --container: 1280px;
  --sidebar-w: 260px;
  --toc-w: 220px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; min-height: 100%; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Inter", "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.6;
}

.bg {
  position: fixed; inset: 0; z-index: -1;
  background:
    radial-gradient(circle at 18% 8%, rgba(212, 180, 138, 0.10), transparent 40%),
    radial-gradient(circle at 82% 92%, rgba(212, 180, 138, 0.05), transparent 50%),
    var(--bg);
  pointer-events: none;
}

a {
  color: var(--gold-2);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .15s ease, color .15s ease;
}
a:hover { border-bottom-color: var(--gold-2); }
a:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 4px;
}

.muted { color: var(--muted); }
.gold { color: var(--gold-2); }

.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; top: -40px; left: 12px;
  background: var(--gold);
  color: var(--bg);
  padding: 8px 14px;
  border-radius: 6px;
  z-index: 1000;
  font-weight: 600;
}
.skip-link:focus { top: 12px; }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10, 10, 15, 0.78);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  color: var(--fg);
  border-bottom: none;
  letter-spacing: -0.01em;
}
.brand:hover { border-bottom: none; }
.brand-name { font-size: 16px; }
.brand-sub {
  color: var(--muted);
  font-size: 13px;
  font-weight: 400;
  margin-left: 4px;
  padding-left: 10px;
  border-left: 1px solid var(--line-strong);
}
.dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 12px var(--gold);
}
.nav-links {
  list-style: none; margin: 0 0 0 auto; padding: 0;
  display: flex; gap: 6px;
  align-items: center;
}
.nav-links a {
  display: inline-block;
  padding: 8px 12px;
  color: var(--muted);
  font-size: 14px;
  border-radius: 6px;
  border-bottom: none;
}
.nav-links a:hover { color: var(--fg); border-bottom: none; }
.nav-search {
  position: relative;
  margin-left: 16px;
  width: 280px;
}
.nav-search input {
  width: 100%;
  background: var(--bg-2);
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  padding: 8px 12px 8px 34px;
  font-size: 13.5px;
  color: var(--fg);
  font-family: inherit;
}
.nav-search input::placeholder { color: var(--muted); }
.nav-search input:focus {
  outline: none;
  border-color: var(--gold-2);
  box-shadow: 0 0 0 3px rgba(212, 180, 138, 0.16);
}
.nav-search svg {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 14px;
  color: var(--muted);
  pointer-events: none;
}
.nav-search-results {
  position: absolute;
  top: calc(100% + 6px);
  left: 0; right: 0;
  background: var(--bg-2);
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  max-height: 380px;
  overflow-y: auto;
  display: none;
  box-shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.6);
}
.nav-search-results.open { display: block; }
.nav-search-results a {
  display: block;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  color: var(--fg);
  font-size: 13.5px;
}
.nav-search-results a:last-child { border-bottom: none; }
.nav-search-results a:hover,
.nav-search-results a:focus {
  background: rgba(212, 180, 138, 0.08);
  border-bottom-color: var(--line);
}
.nav-search-results .cat {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--gold);
  margin-bottom: 2px;
}
.nav-search-results .empty {
  padding: 16px; color: var(--muted); font-size: 13.5px;
}

@media (max-width: 880px) {
  .nav-links { display: none; }
  .nav-search { display: none; }
}

.menu-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  width: 38px; height: 38px;
  color: var(--fg);
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
}
.menu-toggle svg { width: 18px; height: 18px; }
@media (max-width: 880px) {
  .menu-toggle { display: inline-flex; margin-left: auto; }
}

/* Layout */
.layout {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 24px 80px;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr) var(--toc-w);
  gap: 40px;
  align-items: start;
}
@media (max-width: 1100px) {
  .layout { grid-template-columns: var(--sidebar-w) minmax(0, 1fr); }
  .toc-col { display: none; }
}
@media (max-width: 880px) {
  .layout {
    grid-template-columns: minmax(0, 1fr);
    padding: 20px 20px 56px;
    gap: 0;
  }
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: 80px;
  align-self: start;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding-right: 8px;
}
@media (max-width: 880px) {
  .sidebar {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    width: 86%;
    max-width: 320px;
    background: var(--bg-2);
    border-right: 1px solid var(--line-strong);
    z-index: 60;
    padding: 24px 20px;
    transform: translateX(-100%);
    transition: transform .25s ease;
    max-height: 100vh;
  }
  .sidebar.open { transform: translateX(0); }
  .sidebar-backdrop {
    position: fixed; inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 55;
    display: none;
  }
  .sidebar-backdrop.open { display: block; }
}
.sidebar h2 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gold);
  font-weight: 600;
  margin: 22px 0 10px;
}
.sidebar h2:first-child { margin-top: 0; }
.sidebar ul {
  list-style: none; margin: 0 0 8px; padding: 0;
}
.sidebar li { margin: 0; }
.sidebar a {
  display: block;
  padding: 7px 12px;
  font-size: 14px;
  color: var(--muted);
  border-radius: 6px;
  border-bottom: none;
  line-height: 1.4;
}
.sidebar a:hover {
  color: var(--fg);
  background: rgba(255, 255, 255, 0.03);
  border-bottom: none;
}
.sidebar a[aria-current="page"] {
  color: var(--gold-2);
  background: var(--gold-bg);
  border: 1px solid var(--gold-border);
}

/* Main content */
.content {
  min-width: 0;
}
.content article {
  max-width: 720px;
}
.content h1 {
  font-size: clamp(30px, 4vw, 42px);
  line-height: 1.15;
  margin: 0 0 14px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.content .lede {
  font-size: 17px;
  color: var(--muted);
  margin: 0 0 36px;
  line-height: 1.55;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line);
}
.content h2 {
  font-size: 22px;
  font-weight: 600;
  margin: 44px 0 14px;
  letter-spacing: -0.015em;
  scroll-margin-top: 80px;
}
.content h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 28px 0 10px;
  scroll-margin-top: 80px;
}
.content p {
  margin: 0 0 16px;
  color: var(--fg);
}
.content ul, .content ol {
  margin: 0 0 18px;
  padding-left: 22px;
}
.content li { margin-bottom: 8px; }
.content li > p { margin-bottom: 8px; }
.content strong { color: var(--fg); font-weight: 600; }
.content code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
  font-size: 13.5px;
  background: var(--bg-3);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 1px 6px;
  color: var(--gold-2);
}
.content pre {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.55;
  margin: 0 0 20px;
}
.content pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: var(--fg);
  font-size: 13px;
}
.content table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 0 0 22px;
}
.content th, .content td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
}
.content th {
  font-weight: 600;
  color: var(--gold);
  font-size: 12.5px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.content blockquote {
  margin: 0 0 20px;
  padding: 14px 18px;
  border-left: 3px solid var(--gold);
  background: var(--gold-bg);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--fg);
}
.content blockquote p:last-child { margin-bottom: 0; }
.content .callout {
  margin: 0 0 22px;
  padding: 16px 18px;
  background: var(--bg-2);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
}
.content .callout strong { color: var(--gold-2); }
.content .callout p:last-child { margin-bottom: 0; }

.crumb {
  font-size: 12.5px;
  color: var(--muted);
  margin-bottom: 18px;
  letter-spacing: 0.02em;
}
.crumb a { color: var(--muted); border-bottom: none; }
.crumb a:hover { color: var(--fg); border-bottom: none; }

.next-prev {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.next-prev a {
  display: block;
  padding: 16px 18px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  color: var(--fg);
  border-bottom: 1px solid var(--line);
}
.next-prev a:hover {
  border-color: var(--gold-border);
  background: rgba(212, 180, 138, 0.04);
}
.next-prev .label {
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 4px;
}
.next-prev .title { font-weight: 500; color: var(--gold-2); }
.next-prev .next { text-align: right; }
@media (max-width: 600px) {
  .next-prev { grid-template-columns: 1fr; }
  .next-prev .next { text-align: left; }
}

/* TOC (right column) */
.toc-col {
  position: sticky;
  top: 80px;
  align-self: start;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  font-size: 13.5px;
}
.toc-col h2 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gold);
  font-weight: 600;
  margin: 0 0 12px;
}
.toc-col ul { list-style: none; padding: 0; margin: 0; border-left: 1px solid var(--line); }
.toc-col li { margin: 0; }
.toc-col a {
  display: block;
  padding: 5px 0 5px 14px;
  color: var(--muted);
  border-left: 2px solid transparent;
  margin-left: -1px;
  border-bottom: none;
  font-size: 13px;
  line-height: 1.45;
}
.toc-col a:hover { color: var(--fg); border-bottom: none; }
.toc-col a.active {
  color: var(--gold-2);
  border-left-color: var(--gold);
}
.toc-col a.h3 { padding-left: 26px; font-size: 12.5px; }

/* Home (article index) */
.home-hero { margin-bottom: 44px; }
.home-hero h1 {
  font-size: clamp(34px, 5vw, 52px);
  line-height: 1.05;
  margin: 0 0 14px;
  font-weight: 600;
  letter-spacing: -0.025em;
  background: linear-gradient(180deg, var(--fg) 0%, #c8c8d4 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.home-hero p {
  font-size: 17px;
  color: var(--muted);
  max-width: 620px;
  margin: 0 0 28px;
  line-height: 1.55;
}
.home-hero .home-search {
  position: relative;
  max-width: 520px;
}
.home-hero .home-search input {
  width: 100%;
  background: var(--bg-2);
  border: 1px solid var(--line-strong);
  border-radius: 10px;
  padding: 12px 16px 12px 42px;
  font-size: 15px;
  color: var(--fg);
  font-family: inherit;
}
.home-hero .home-search input:focus {
  outline: none;
  border-color: var(--gold-2);
  box-shadow: 0 0 0 3px rgba(212, 180, 138, 0.18);
}
.home-hero .home-search svg {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--muted);
}

.home-cats { display: flex; flex-direction: column; gap: 36px; }
.home-cat h2 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gold);
  font-weight: 600;
  margin: 0 0 16px;
}
.home-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(2, 1fr);
}
@media (max-width: 700px) { .home-grid { grid-template-columns: 1fr; } }

.home-card {
  display: block;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  color: var(--fg);
  border-bottom: 1px solid var(--line);
  transition: border-color .15s ease, background .15s ease;
}
.home-card:hover {
  border-color: var(--gold-border);
  background: rgba(212, 180, 138, 0.03);
  border-bottom-color: var(--gold-border);
}
.home-card h3 {
  font-size: 15.5px;
  font-weight: 600;
  margin: 0 0 6px;
  color: var(--fg);
  letter-spacing: -0.01em;
}
.home-card p {
  margin: 0;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.5;
}

.home-search-results {
  margin-top: 18px;
  display: none;
  flex-direction: column;
  gap: 10px;
}
.home-search-results.open { display: flex; }
.home-search-results .empty { color: var(--muted); font-size: 14px; }

/* Footer */
.footer {
  border-top: 1px solid var(--line);
  padding: 32px 0 40px;
  color: var(--muted);
  font-size: 13.5px;
}
.footer-inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  align-items: center;
  justify-content: space-between;
}
.footer a { color: var(--muted); border-bottom: none; }
.footer a:hover { color: var(--fg); border-bottom: none; }
.footer ul { display: flex; flex-wrap: wrap; gap: 6px 22px; list-style: none; margin: 0; padding: 0; }

.loading {
  padding: 80px 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.not-found {
  padding: 60px 0;
  max-width: 520px;
}
.not-found h1 { margin-top: 0; }