:root {
  --bg: #050607;
  --bg-1: #0a0c0f;
  --bg-2: #101318;
  --line: rgba(255, 255, 255, 0.07);
  --line-2: rgba(255, 255, 255, 0.13);
  --text: #e8ecf1;
  --text-2: #c3cad3;
  --muted: #8b95a3;
  --dim: #5d6672;
  --accent: #a0acbb;
  --ok: #3fb68b;
  --bad: #e5484d;
  --warn: #c9a14a;
  --header: 60px;
  --side: 272px;
  --toc: 232px;
  --sans: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --display: Poppins, Inter, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--header) + 24px); -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text-2); font: 400 15px/1.75 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
::selection { background: rgba(160, 172, 187, 0.3); color: #fff; }
.i { width: 16px; height: 16px; flex: none; }
.i.sm { width: 12px; height: 12px; }
kbd { font: 500 11px/1 var(--sans); color: var(--muted); border: 1px solid var(--line-2); border-radius: 4px; padding: 3px 5px; background: var(--bg-1); }
.skip { position: absolute; left: -999px; top: 8px; z-index: 100; background: #fff; color: #000; padding: 6px 10px; border-radius: 4px; }
.skip:focus { left: 8px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

/* header */
.top { position: fixed; inset: 0 0 auto 0; height: var(--header); z-index: 40; display: flex; align-items: center; gap: 16px; padding: 0 24px; background: rgba(5, 6, 7, 0.82); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); flex: none; }
.brand img { display: block; }
.brand-name { font: 600 16px/1 var(--display); letter-spacing: -0.02em; }
.brand-sep { width: 1px; height: 16px; background: var(--line-2); }
.brand-label { font: 500 14px/1 var(--sans); color: var(--muted); }
.search-btn { display: flex; align-items: center; gap: 10px; height: 34px; padding: 0 8px 0 12px; border: 1px solid var(--line-2); border-radius: 6px; background: var(--bg-1); color: var(--muted); font: 400 13px var(--sans); cursor: pointer; transition: border-color .15s, color .15s; }
.search-btn:hover { border-color: rgba(255, 255, 255, 0.22); color: var(--text-2); }
.search-btn span { flex: 1; text-align: left; }
.top .search-btn { width: 300px; margin-left: auto; }
.top-links { display: flex; align-items: center; gap: 20px; font-size: 13px; }
.top-links a { display: flex; align-items: center; gap: 5px; color: var(--muted); text-decoration: none; transition: color .15s; }
.top-links a:hover { color: var(--text); }
.menu-btn { display: none; background: none; border: 0; color: var(--text); padding: 6px; margin-left: -6px; cursor: pointer; }
.menu-btn .i { width: 20px; height: 20px; }

/* shell */
.shell { display: grid; grid-template-columns: var(--side) minmax(0, 1fr) var(--toc); padding-top: var(--header); max-width: 1480px; margin: 0 auto; }
.sidebar { position: sticky; top: var(--header); height: calc(100vh - var(--header)); overflow-y: auto; padding: 24px 16px 24px 24px; border-right: 1px solid var(--line); display: flex; flex-direction: column; scrollbar-width: thin; scrollbar-color: var(--line-2) transparent; }
.search-btn.side { display: none; width: 100%; margin-bottom: 20px; }
.nav-group + .nav-group { margin-top: 6px; }
.nav-head { width: 100%; display: flex; align-items: center; gap: 10px; padding: 7px 8px; background: none; border: 0; border-radius: 6px; color: var(--text); font: 500 13px/1.3 var(--sans); cursor: pointer; text-align: left; }
.nav-head:hover { background: rgba(255, 255, 255, 0.03); }
.nav-head .i { color: var(--muted); }
.nav-head span { flex: 1; }
.nav-head .chev { width: 14px; height: 14px; color: var(--dim); transition: transform .2s; }
.nav-group.open .chev { transform: rotate(90deg); }
.nav-group ul { list-style: none; margin: 2px 0 10px 15px; padding: 0 0 0 0; border-left: 1px solid var(--line); display: none; }
.nav-group.open ul { display: block; }
.nav-group li a { display: block; position: relative; padding: 5px 10px 5px 17px; font-size: 13.5px; line-height: 1.45; color: var(--muted); text-decoration: none; border-radius: 0 6px 6px 0; transition: color .15s, background .15s; }
.nav-group li a:hover { color: var(--text); }
.nav-group li a.active { color: var(--text); background: rgba(255, 255, 255, 0.04); }
.nav-group li a.active::before { content: ""; position: absolute; left: -1px; top: 6px; bottom: 6px; width: 2px; border-radius: 2px; background: var(--text); }
.side-foot { margin-top: auto; padding: 24px 8px 0; font-size: 12px; color: var(--dim); }

/* content */
.content { min-width: 0; padding: 40px 56px 64px; }
.content > * { max-width: 760px; margin-left: auto; margin-right: auto; }
.crumbs { display: flex; flex-wrap: wrap; gap: 8px; font-size: 13px; color: var(--dim); margin-bottom: 28px; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--text); }
.crumbs .cur { color: var(--text-2); }
.page-head { padding-bottom: 28px; margin-bottom: 36px; border-bottom: 1px solid var(--line); }
.status { display: inline-flex; align-items: center; gap: 8px; font: 500 11px/1 var(--sans); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); border: 1px solid var(--line-2); border-radius: 999px; padding: 6px 10px; margin-bottom: 18px; }
.status .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
h1 { font: 600 40px/1.12 var(--display); letter-spacing: -0.035em; color: var(--text); margin: 0; }
.lede { font-size: 17px; line-height: 1.6; color: var(--muted); margin: 14px 0 0; }

.prose > :first-child { margin-top: 0; }
.prose p { margin: 0 0 18px; }
.prose h2, .prose h3, .prose h4 { position: relative; color: var(--text); scroll-margin-top: calc(var(--header) + 24px); }
.prose h2 { font: 600 24px/1.3 var(--display); letter-spacing: -0.025em; margin: 52px 0 16px; padding-top: 4px; }
.prose h3 { font: 600 17px/1.4 var(--sans); letter-spacing: -0.01em; margin: 34px 0 10px; }
.prose h4 { font: 600 15px/1.4 var(--sans); margin: 26px 0 8px; }
.anchor { position: absolute; left: -26px; top: 50%; transform: translateY(-50%); color: var(--dim); opacity: 0; transition: opacity .15s; padding: 4px; display: flex; }
.prose h2:hover .anchor, .prose h3:hover .anchor, .anchor:focus { opacity: 1; }
.anchor .i { width: 14px; height: 14px; }
.prose a:not(.anchor) { color: var(--text); text-decoration: underline; text-decoration-color: rgba(255, 255, 255, 0.25); text-underline-offset: 3px; transition: text-decoration-color .15s; }
.prose a:not(.anchor):hover { text-decoration-color: var(--text); }
.prose strong { color: var(--text); font-weight: 600; }
.prose ul, .prose ol { margin: 0 0 18px; padding-left: 22px; }
.prose li { margin: 5px 0; }
.prose li::marker { color: var(--dim); }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
.prose :not(pre) > code { font: 500 0.86em var(--mono); color: var(--text); background: var(--bg-2); border: 1px solid var(--line); border-radius: 4px; padding: 1px 5px; }
.prose blockquote { margin: 0 0 18px; padding: 2px 0 2px 16px; border-left: 2px solid var(--line-2); color: var(--muted); }

.table-wrap { overflow-x: auto; margin: 0 0 24px; border: 1px solid var(--line); border-radius: 8px; }
table { width: 100%; border-collapse: collapse; font-size: 13.5px; line-height: 1.55; }
th { text-align: left; font-weight: 500; color: var(--text); background: var(--bg-1); }
th, td { padding: 10px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
tr:last-child td { border-bottom: 0; }
td code { white-space: nowrap; }

.callout { margin: 0 0 24px; padding: 14px 16px 2px; border: 1px solid var(--line); border-left: 2px solid var(--accent); border-radius: 0 6px 6px 0; background: var(--bg-1); font-size: 14px; }
.callout-title { font: 600 11px/1 var(--sans); letter-spacing: .09em; text-transform: uppercase; color: var(--text); margin-bottom: 8px; }
.callout p { margin-bottom: 12px; }
.callout-warning, .callout-caution { border-left-color: var(--warn); }
.callout-illustrative { border-left-color: var(--dim); border-left-style: dashed; }
.callout-tip { border-left-color: var(--ok); }

.code { margin: 0 0 24px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg-1); overflow: hidden; }
.code-head { display: flex; align-items: center; justify-content: space-between; height: 36px; padding: 0 8px 0 14px; border-bottom: 1px solid var(--line); font: 500 12px var(--sans); color: var(--muted); }
.copy { font: 500 12px var(--sans); color: var(--muted); background: none; border: 1px solid transparent; border-radius: 5px; padding: 4px 8px; cursor: pointer; transition: color .15s, border-color .15s; }
.copy:hover { color: var(--text); border-color: var(--line-2); }
.copy.done { color: var(--ok); }
.code pre { margin: 0; padding: 16px; overflow-x: auto; font: 400 13px/1.7 var(--mono); color: #d5dbe3; scrollbar-width: thin; }
.hljs-keyword, .hljs-built_in, .hljs-literal { color: #b4bfcc; font-weight: 500; }
.hljs-string { color: #9fc3a8; }
.hljs-number { color: #d6b98c; }
.hljs-comment { color: #5d6672; font-style: italic; }
.hljs-attr, .hljs-property { color: #a9b8d4; }
.hljs-title, .hljs-title.function_ { color: #e8ecf1; }
.hljs-type, .hljs-title.class_ { color: #c9d2de; }
.hljs-punctuation, .hljs-operator { color: #8b95a3; }
.hljs-variable, .hljs-params { color: #d5dbe3; }

/* diagrams */
.diagram { margin: 8px 0 32px; border: 1px solid var(--line); border-radius: 8px; background: radial-gradient(circle at 1px 1px, rgba(255,255,255,0.05) 1px, transparent 0) 0 0 / 16px 16px, var(--bg-1); }
.diagram-scroll { overflow-x: auto; padding: 20px; }
.diagram svg { display: block; width: 100%; min-width: 620px; height: auto; }
.diagram figcaption { border-top: 1px solid var(--line); padding: 10px 16px; font-size: 12.5px; color: var(--muted); }
.d-node rect { fill: var(--bg-2); stroke: var(--line-2); stroke-width: 1; }
.d-node.d-thin rect { fill: rgba(255,255,255,0.02); }
.d-group rect { fill: rgba(255, 255, 255, 0.015); stroke: rgba(255, 255, 255, 0.16); stroke-dasharray: 4 4; }
.d-label { fill: var(--text); font: 500 13px var(--sans); }
.d-label.d-small { font-size: 12px; }
.d-sub { fill: var(--muted); font: 400 11px var(--sans); }
.d-kicker { fill: var(--muted); font: 600 10px var(--sans); letter-spacing: .12em; }
.d-step { fill: var(--dim); font: 500 11px var(--mono); }
.d-edge { stroke: #7d8794; stroke-width: 1.2; }
.d-edge.d-faint { stroke: #4c545e; }
.d-edge.d-dash { stroke-dasharray: 4 4; }
.d-head { fill: #7d8794; }
.d-ok rect { stroke: rgba(63, 182, 139, 0.45); }
.d-ok .d-dot { fill: var(--ok); }
.d-bad rect { stroke: rgba(229, 72, 77, 0.45); }
.d-bad .d-dot { fill: var(--bad); }
.d-warn rect { stroke: rgba(201, 161, 74, 0.4); }
.d-warn .d-dot { fill: var(--warn); }
.d-bad-stroke { stroke: rgba(229, 72, 77, 0.7); }
.d-bad-text { fill: #e58a8d; }
.d-ok-text { fill: #7fcaa9; }

/* pager + footer */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 56px; }
.pager a { display: flex; flex-direction: column; gap: 4px; padding: 16px 18px; border: 1px solid var(--line); border-radius: 8px; text-decoration: none; transition: border-color .15s; }
.pager a:hover { border-color: rgba(255, 255, 255, 0.24); }
.pager span { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--muted); }
.pager strong { font-weight: 500; color: var(--text); font-size: 15px; }
.pager .next { text-align: right; align-items: flex-end; }
.foot { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; margin-top: 48px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 12px; color: var(--dim); }

/* toc */
.toc { position: sticky; top: var(--header); height: calc(100vh - var(--header)); overflow-y: auto; padding: 44px 24px 24px 8px; font-size: 13px; }
.toc-title { font: 500 12px var(--sans); color: var(--text); margin-bottom: 12px; }
.toc ul { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--line); }
.toc li a { display: block; padding: 4px 0 4px 14px; margin-left: -1px; border-left: 1px solid transparent; color: var(--muted); text-decoration: none; line-height: 1.45; transition: color .15s, border-color .15s; }
.toc li.l3 a { padding-left: 26px; font-size: 12.5px; }
.toc li a:hover { color: var(--text); }
.toc li a.active { color: var(--text); border-left-color: var(--text); }

/* search */
.search-dialog { position: fixed; inset: 0; z-index: 60; background: rgba(0, 0, 0, 0.6); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); display: flex; align-items: flex-start; justify-content: center; padding: 12vh 16px 16px; }
.search-dialog[hidden] { display: none; }
.search-panel { width: 100%; max-width: 640px; background: var(--bg-1); border: 1px solid var(--line-2); border-radius: 10px; box-shadow: 0 24px 80px rgba(0, 0, 0, 0.6); overflow: hidden; }
.search-input { display: flex; align-items: center; gap: 10px; padding: 0 14px; border-bottom: 1px solid var(--line); color: var(--muted); }
.search-input input { flex: 1; height: 52px; background: none; border: 0; outline: 0; color: var(--text); font: 400 15px var(--sans); }
.search-input input::-webkit-search-cancel-button { display: none; }
.search-results { list-style: none; margin: 0; padding: 8px; max-height: 56vh; overflow-y: auto; }
.search-results li a { display: block; padding: 10px 12px; border-radius: 6px; text-decoration: none; }
.search-results li a .r-sec { font-size: 11px; color: var(--dim); letter-spacing: .04em; }
.search-results li a .r-title { color: var(--text); font-weight: 500; font-size: 14px; }
.search-results li a .r-snip { font-size: 12.5px; color: var(--muted); line-height: 1.5; margin-top: 2px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.search-results li a mark { background: none; color: var(--text); font-weight: 600; }
.search-results li[aria-selected="true"] a { background: rgba(255, 255, 255, 0.06); }
.search-empty { padding: 28px 12px; text-align: center; color: var(--muted); font-size: 13px; }
.search-foot { display: flex; gap: 18px; padding: 10px 14px; border-top: 1px solid var(--line); font-size: 12px; color: var(--dim); }
.search-foot kbd { margin-right: 4px; }

.scrim { position: fixed; inset: var(--header) 0 0 0; z-index: 29; background: rgba(0, 0, 0, 0.55); }

/* responsive */
@media (max-width: 1240px) {
  .shell { grid-template-columns: var(--side) minmax(0, 1fr); }
  .toc { display: none; }
}
@media (max-width: 900px) {
  .menu-btn { display: flex; }
  .top { padding: 0 16px; gap: 12px; }
  .top .search-btn { width: auto; padding: 0 10px; }
  .top .search-btn span, .top .search-btn kbd, .brand-sep, .brand-label { display: none; }
  .top-links { gap: 14px; }
  .top-links a:first-child { display: none; }
  .shell { grid-template-columns: minmax(0, 1fr); }
  .sidebar { position: fixed; z-index: 30; top: var(--header); left: 0; width: min(320px, 86vw); background: var(--bg); transform: translateX(-100%); transition: transform .25s ease; padding: 20px 16px; }
  body.nav-open .sidebar { transform: none; }
  body.nav-open { overflow: hidden; }
  .search-btn.side { display: flex; }
  .content { padding: 28px 16px 48px; }
  h1 { font-size: 31px; }
  .lede { font-size: 16px; }
  .anchor { display: none; }
  .pager { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }