:root {
  --ink: #0b1215;
  --ink-2: #111d21;
  --panel: #142126;
  --paper: #edf0e9;
  --paper-2: #dfe5dc;
  --text: #172023;
  --muted: #61706c;
  --line: #c7d0c8;
  --dark-line: rgba(205, 230, 224, .17);
  --amber: #e5a92e;
  --cyan: #248f8a;
  --red: #c95849;
  --serif: "Source Han Serif SC", "Noto Serif CJK SC", "Songti SC", SimSun, serif;
  --sans: "Source Han Sans SC", "Noto Sans CJK SC", "Microsoft YaHei UI", sans-serif;
  --mono: "Cascadia Code", "JetBrains Mono", Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 82px; }
body { margin: 0; color: var(--text); background: var(--paper); font-family: var(--sans); line-height: 1.78; }
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image: linear-gradient(rgba(11,18,21,.025) 1px, transparent 1px), linear-gradient(90deg, rgba(11,18,21,.025) 1px, transparent 1px);
  background-size: 36px 36px;
}
::selection { color: var(--ink); background: #f3c462; }
a { color: var(--cyan); text-underline-offset: 4px; }
a:hover { color: #126a67; }
:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }

.reading-progress { position: fixed; inset: 0 0 auto; z-index: 60; height: 3px; background: transparent; }
.reading-progress span { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--cyan), var(--amber), var(--red)); }

.doc-header { position: sticky; top: 0; z-index: 50; color: #edf3ef; background: rgba(11,18,21,.93); border-bottom: 1px solid var(--dark-line); backdrop-filter: blur(16px); }
.doc-header-inner { max-width: 1500px; min-height: 58px; margin: auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: #edf3ef; text-decoration: none; font-family: var(--mono); font-size: 12px; letter-spacing: .08em; }
.brand-mark { width: 24px; height: 24px; display: grid; place-items: center; color: var(--amber); border: 1px solid var(--amber); transform: rotate(45deg); }
.brand-mark b { transform: rotate(-45deg); font-weight: 500; }
.header-actions { display: flex; align-items: center; gap: 8px; }
.header-link { padding: 6px 9px; color: #aebdb8; border: 1px solid var(--dark-line); text-decoration: none; font-size: 11px; }
.header-link:hover { color: #fff; border-color: var(--amber); }

.document-shell { max-width: 1500px; margin: auto; display: grid; grid-template-columns: 230px minmax(0, 820px) 230px; gap: clamp(28px, 4vw, 64px); padding: 54px 24px 80px; justify-content: center; }
.toc, .context { position: sticky; top: 92px; align-self: start; max-height: calc(100vh - 116px); overflow: auto; scrollbar-width: thin; }
.rail-label { margin: 0 0 14px; color: var(--muted); font-family: var(--mono); font-size: 10px; letter-spacing: .12em; text-transform: uppercase; }
.rail-label::before { content: "＋ "; color: var(--amber); }
.toc ul { margin: 0; padding: 0; list-style: none; border-left: 1px solid var(--line); }
.toc li { margin: 0; }
.toc li ul { margin-left: 12px; border-left: 0; }
.toc a { display: block; padding: 5px 0 5px 13px; color: var(--muted); text-decoration: none; font-size: 11px; line-height: 1.45; border-left: 2px solid transparent; transform: translateX(-1px); }
.toc a:hover, .toc a.active { color: var(--text); border-left-color: var(--amber); }
.toc li li a { color: #7a8884; font-size: 10px; }

.doc-main { min-width: 0; }
.doc-identity { margin-bottom: 44px; padding-bottom: 30px; border-bottom: 1px solid var(--line); }
.breadcrumb { color: var(--muted); font-family: var(--mono); font-size: 10px; letter-spacing: .06em; }
.breadcrumb a { color: inherit; text-decoration: none; }
.breadcrumb a:hover { color: var(--cyan); }
.doc-source-note { display: flex; gap: 10px; align-items: flex-start; margin-top: 22px; padding: 12px 14px; color: #53625e; background: rgba(36,143,138,.065); border: 1px solid rgba(36,143,138,.24); font-size: 11px; }
.doc-source-note::before { content: "ORIGINAL"; flex: 0 0 auto; color: var(--cyan); font-family: var(--mono); font-size: 9px; letter-spacing: .08em; }

.markdown-body { font-size: 16px; }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 { position: relative; font-family: var(--serif); color: #11191b; line-height: 1.25; letter-spacing: -.025em; }
.markdown-body h1 { margin: 0 0 30px; font-size: clamp(42px, 5.4vw, 68px); }
.markdown-body h2 { margin: 64px 0 20px; padding: 14px 0 12px; font-size: 34px; border-top: 2px solid var(--text); border-bottom: 1px solid var(--line); }
.markdown-body h2::before { content: attr(data-section); display: block; margin-bottom: 8px; color: var(--amber); font-family: var(--mono); font-size: 10px; letter-spacing: .14em; }
.markdown-body h3 { margin: 38px 0 13px; font-size: 24px; }
.markdown-body h4 { margin: 28px 0 10px; font-size: 19px; }
.markdown-body p { margin: 0 0 18px; }
.markdown-body strong { color: #0c5552; }
.markdown-body hr { margin: 48px 0; border: 0; border-top: 1px dashed var(--line); }
.markdown-body ul, .markdown-body ol { margin: 0 0 22px; padding-left: 1.4em; }
.markdown-body li { margin: 5px 0; }
.markdown-body li::marker { color: var(--amber); font-family: var(--mono); }
.markdown-body blockquote { margin: 25px 0; padding: 16px 20px; color: #465450; background: #e3e8e0; border-left: 4px solid var(--amber); }
.markdown-body blockquote p:last-child { margin-bottom: 0; }
.markdown-body code { padding: .12em .35em; color: #7c342d; background: rgba(201,88,73,.09); border: 1px solid rgba(201,88,73,.14); font-family: var(--mono); font-size: .86em; }
.markdown-body pre { margin: 24px 0; padding: 20px; overflow: auto; color: #dce7e2; background: var(--ink); border: 1px solid #283a40; line-height: 1.58; }
.markdown-body pre code { padding: 0; color: inherit; background: transparent; border: 0; font-size: 12px; }
.markdown-body pre code.language-mermaid::before { content: "MERMAID SOURCE / 图示源码"; display: block; margin-bottom: 12px; color: var(--amber); font-size: 9px; letter-spacing: .1em; }
.table-wrap { margin: 26px 0; overflow-x: auto; border: 1px solid var(--line); }
.markdown-body table { width: 100%; border-collapse: collapse; min-width: 560px; font-size: 13px; }
.markdown-body th { color: #edf3ef; background: var(--ink-2); text-align: left; font-weight: 500; }
.markdown-body th, .markdown-body td { padding: 11px 13px; border: 1px solid var(--line); vertical-align: top; }
.markdown-body tr:nth-child(even) td { background: rgba(11,18,21,.025); }
.markdown-body input[type="checkbox"] { accent-color: var(--cyan); }
.heading-anchor { position: absolute; right: 0; top: 50%; opacity: 0; color: var(--muted); text-decoration: none; font-family: var(--mono); font-size: 12px; transform: translateY(-50%); transition: opacity .2s; }
.markdown-body h2:hover .heading-anchor, .markdown-body h3:hover .heading-anchor, .heading-anchor:focus { opacity: 1; }

.context-card { margin-bottom: 12px; padding: 15px; background: rgba(255,255,255,.38); border: 1px solid var(--line); }
.context-card h2 { margin: 0 0 9px; color: var(--text); font-family: var(--serif); font-size: 16px; }
.context-card p { margin: 0 0 11px; color: var(--muted); font-size: 10px; }
.context-links { display: grid; gap: 6px; }
.context-links a { display: flex; justify-content: space-between; gap: 8px; color: #344440; text-decoration: none; font-size: 10px; }
.context-links a::after { content: "↗"; color: var(--amber); }
.context-links a:hover { color: var(--cyan); }
.source-meta { margin-top: 12px; padding-top: 10px; border-top: 1px dashed var(--line); color: #788681; font-family: var(--mono); font-size: 9px; word-break: break-all; }

.doc-pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 72px; padding-top: 24px; border-top: 1px solid var(--line); }
.pager-link { padding: 15px; color: var(--text); border: 1px solid var(--line); text-decoration: none; font-size: 11px; }
.pager-link:hover { color: var(--text); border-color: var(--cyan); }
.pager-link small { display: block; margin-bottom: 4px; color: var(--muted); font-family: var(--mono); }
.pager-link.next { text-align: right; }
.pager-link.empty { visibility: hidden; }

.doc-footer { color: #a8b8b2; background: var(--ink); border-top: 1px solid #26383d; }
.doc-footer-inner { max-width: 1500px; margin: auto; padding: 28px 24px; display: flex; justify-content: space-between; gap: 30px; font-size: 10px; }
.doc-footer a { color: var(--amber); }

@media (max-width: 1180px) {
  .document-shell { grid-template-columns: 190px minmax(0, 800px); }
  .context { display: none; }
}
@media (max-width: 820px) {
  html { scroll-padding-top: 66px; }
  .doc-header-inner { padding: 0 14px; }
  .header-actions .header-link:first-child { display: none; }
  .document-shell { display: block; padding: 30px 18px 60px; }
  .toc { position: static; max-height: none; margin-bottom: 34px; padding: 16px; background: #e3e8e0; border: 1px solid var(--line); }
  .toc > ul { columns: 2; column-gap: 22px; }
  .toc li { break-inside: avoid; }
  .toc li ul { display: none; }
  .markdown-body { font-size: 15px; }
  .markdown-body h1 { font-size: 42px; }
  .markdown-body h2 { margin-top: 48px; font-size: 28px; }
  .markdown-body h3 { font-size: 22px; }
  .doc-pager { grid-template-columns: 1fr; }
  .doc-footer-inner { display: block; }
}
@media (max-width: 480px) {
  .brand span:last-child { display: none; }
  .toc > ul { columns: 1; }
  .markdown-body h1 { font-size: 36px; }
  .markdown-body h2 { font-size: 25px; }
  .doc-source-note { display: block; }
  .doc-source-note::before { display: block; margin-bottom: 6px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}
@media print {
  .doc-header, .toc, .context, .doc-pager, .reading-progress, .doc-footer { display: none !important; }
  body { background: white; }
  .document-shell { display: block; max-width: 900px; padding: 0; }
  .doc-source-note { border-color: #aaa; }
  .markdown-body a { color: #111; }
}