:root {
      --bg: #fff;
      --ink: #121316;
      --muted: #656a73;
      --line: #d9dce1;
      --soft: #f5f6f8;
      --blue: #06c;
      --blue-soft: #eaf2ff;
      --green: #16835c;
      --orange: #a14b11;
      --purple: #635bce;
      --max: 1220px;
    }
    * { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 72px; }
    body {
      margin: 0;
      background: var(--bg);
      color: var(--ink);
      font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
        "Segoe UI", sans-serif;
      line-height: 1.76;
      letter-spacing: .01em;
    }
    a {
      color: var(--blue);
      text-decoration-thickness: 1px;
      text-underline-offset: 3px;
    }
    a:focus-visible, button:focus-visible, summary:focus-visible {
      outline: 3px solid #78a9ff;
      outline-offset: 3px;
    }
    .progress {
      position: fixed;
      inset: 0 0 auto;
      height: 3px;
      background: var(--blue);
      transform: scaleX(0);
      transform-origin: left;
      z-index: 100;
    }
    .topbar {
      position: sticky;
      top: 0;
      z-index: 50;
      border-bottom: 1px solid rgba(0,0,0,.12);
      background: rgba(255,255,255,.93);
      backdrop-filter: saturate(160%) blur(16px);
    }
    .topbar-inner {
      max-width: var(--max);
      margin: auto;
      padding: 13px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 18px;
    }
    .brand { font-weight: 700; white-space: nowrap; }
    .topnav {
      display: flex;
      gap: 18px;
      overflow: auto;
      white-space: nowrap;
      font-size: 14px;
    }
    .topnav a { color: #34373c; text-decoration: none; }
    .hero {
      max-width: var(--max);
      margin: auto;
      padding: 102px 24px 78px;
    }
    .eyebrow {
      font-size: 13px;
      font-weight: 700;
      letter-spacing: .13em;
      text-transform: uppercase;
      color: var(--blue);
    }
    h1 {
      font-size: clamp(44px, 7.5vw, 94px);
      line-height: .99;
      letter-spacing: -.06em;
      margin: 18px 0 30px;
      max-width: 1060px;
    }
    h1 span {
      display: block;
      font-size: .46em;
      line-height: 1.16;
      letter-spacing: -.035em;
      color: #3f444c;
      margin-top: 24px;
      max-width: 840px;
    }
    .lead {
      max-width: 930px;
      font-size: clamp(20px, 2.6vw, 30px);
      line-height: 1.38;
      letter-spacing: -.025em;
      color: #3e4249;
    }
    .meta {
      display: flex;
      flex-wrap: wrap;
      gap: 8px 20px;
      margin-top: 34px;
      color: var(--muted);
      font-size: 14px;
    }
    .hero-links { margin-top: 18px; font-size: 14px; }
    .layout {
      max-width: var(--max);
      margin: auto;
      padding: 0 24px 126px;
      display: grid;
      grid-template-columns: 210px minmax(0,1fr);
      gap: 64px;
    }
    .toc {
      position: sticky;
      top: 72px;
      align-self: start;
      max-height: calc(100vh - 92px);
      overflow: auto;
      padding: 20px 0;
      border-top: 1px solid var(--line);
    }
    .toc strong {
      font-size: 12px;
      letter-spacing: .1em;
      text-transform: uppercase;
    }
    .toc a {
      display: block;
      padding: 5px 0;
      color: var(--muted);
      text-decoration: none;
      font-size: 13px;
    }
    .toc a.active { color: var(--ink); font-weight: 700; }
    .content { min-width: 0; }
    section {
      padding: 74px 0;
      border-top: 1px solid var(--line);
    }
    section:first-child { border-top: 0; padding-top: 0; }
    h2 {
      font-size: clamp(31px, 4.3vw, 54px);
      line-height: 1.08;
      letter-spacing: -.04em;
      margin: 0 0 28px;
    }
    h3 {
      font-size: 24px;
      line-height: 1.25;
      letter-spacing: -.025em;
      margin: 42px 0 16px;
    }
    h4 { font-size: 17px; margin: 28px 0 10px; }
    p { max-width: 850px; margin: 12px 0; }
    ul, ol { max-width: 850px; padding-left: 1.35em; }
    li { margin: 7px 0; }
    code {
      font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
      font-size: .9em;
      padding: 1px 5px;
      background: #f0f1f3;
      border-radius: 4px;
    }
    .muted { color: var(--muted); }
    .small { font-size: 13px; }
    .tag {
      display: inline-block;
      padding: 3px 9px;
      margin: 0 6px 6px 0;
      border: 1px solid var(--line);
      font-size: 12px;
    }
    .tag.fact { color: #174ea6; border-color: #8db7ec; }
    .tag.claim { color: #8c4b0b; border-color: #dca979; }
    .tag.interpret { color: #4e4e4e; border-color: #aaaeb5; }
    .tag.extension { color: #5a42a0; border-color: #aaa0d9; }
    .thesis {
      max-width: 940px;
      padding: 28px 0 34px;
      font-size: clamp(23px, 3vw, 35px);
      line-height: 1.34;
      letter-spacing: -.03em;
    }
    .callout {
      margin: 26px 0;
      padding: 21px 24px;
      border-left: 3px solid #8b8e93;
      background: #f7f7f8;
      max-width: 930px;
    }
    .callout strong { display: block; margin-bottom: 5px; }
    .callout.fact { border-color: var(--blue); background: var(--blue-soft); }
    .callout.claim { border-color: var(--orange); background: #fff8f1; }
    .callout.interpret { border-color: #777; }
    .callout.extension { border-color: var(--purple); background: #f7f5ff; }
    .grid-2, .grid-3 {
      display: grid;
      gap: 16px;
      margin: 26px 0;
    }
    .grid-2 { grid-template-columns: repeat(2, minmax(0,1fr)); }
    .grid-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
    .card {
      padding: 24px;
      border: 1px solid var(--line);
      background: #fff;
    }
    .card h3, .card h4 { margin-top: 0; }
    .card .number {
      font-size: 35px;
      line-height: 1;
      letter-spacing: -.05em;
      margin-bottom: 10px;
    }
    .card .number.green { color: var(--green); }
    .card .number.orange { color: var(--orange); }
    .card .number.purple { color: var(--purple); }
    .table-wrap {
      overflow-x: auto;
      margin: 24px 0;
      border-top: 1px solid var(--line);
      border-bottom: 1px solid var(--line);
    }
    table {
      border-collapse: collapse;
      width: 100%;
      min-width: 760px;
      font-size: 14px;
    }
    th, td {
      text-align: left;
      vertical-align: top;
      padding: 12px 13px;
      border-bottom: 1px solid var(--line);
    }
    th {
      font-size: 12px;
      text-transform: uppercase;
      letter-spacing: .05em;
      color: var(--muted);
      background: #fafafa;
    }
    tr:last-child td { border-bottom: 0; }
    .best { font-weight: 750; color: #0b57d0; }
    .warn { color: var(--orange); }
    .good { color: var(--green); }
    .nowrap { white-space: nowrap; }
    .formula {
      max-width: 930px;
      overflow: auto;
      padding: 20px 23px;
      margin: 22px 0;
      border-left: 3px solid var(--blue);
      background: var(--soft);
    }
    mjx-container[jax="CHTML"][display="false"] {
      white-space: nowrap !important;
    }
    .nowrap-math { white-space: nowrap; display: inline-block; }
    .flow {
      margin: 28px 0;
      padding: 27px 0;
      overflow-x: auto;
    }
    .flow-row {
      min-width: 780px;
      display: grid;
      grid-template-columns: repeat(6, minmax(120px,1fr));
      gap: 9px;
      align-items: stretch;
    }
    .flow-node {
      position: relative;
      min-height: 104px;
      padding: 15px 15px 14px;
      border-top: 2px solid var(--ink);
      background: var(--soft);
    }
    .flow-node:not(:last-child)::after {
      content: "→";
      position: absolute;
      right: -12px;
      top: 34px;
      color: var(--muted);
      font-size: 20px;
      z-index: 2;
    }
    .flow-node b { display: block; margin-bottom: 4px; }
    .flow-node small { display: block; color: var(--muted); line-height: 1.5; }
    .flow-node.blue { border-top-color: var(--blue); background: #f3f7ff; }
    .flow-node.purple { border-top-color: var(--purple); background: #f7f5ff; }
    .flow-node.green { border-top-color: var(--green); background: #f3faf7; }
    .lane {
      padding: 18px;
      border: 1px solid var(--line);
      background: #fff;
    }
    .lane + .lane { margin-top: 14px; }
    .lane-title {
      display: flex;
      justify-content: space-between;
      gap: 14px;
      margin-bottom: 13px;
      font-weight: 750;
    }
    .lane-title span { color: var(--muted); font-size: 13px; font-weight: 500; }
    .mini-flow {
      display: flex;
      flex-wrap: wrap;
      align-items: center;
      gap: 7px;
      font-size: 13px;
    }
    .mini-flow i {
      padding: 7px 10px;
      background: var(--soft);
      border: 1px solid var(--line);
      font-style: normal;
    }
    .mini-flow em { color: var(--muted); font-style: normal; }
    .metric-bar { margin: 18px 0; max-width: 850px; }
    .metric-row {
      display: grid;
      grid-template-columns: 150px 1fr 60px;
      gap: 10px;
      align-items: center;
      margin: 9px 0;
      font-size: 13px;
    }
    .track { height: 9px; background: #e7e8ea; }
    .fill { height: 100%; background: var(--blue); }
    .fill.gray { background: #9a9da3; }
    .fill.green { background: var(--green); }
    .fill.purple { background: var(--purple); }
    details {
      max-width: 930px;
      border-top: 1px solid var(--line);
      padding: 13px 0;
    }
    details:last-child { border-bottom: 1px solid var(--line); }
    summary { cursor: pointer; font-weight: 650; padding: 5px 0; }
    .quote {
      max-width: 850px;
      border-left: 1px solid var(--line);
      padding-left: 22px;
      color: #34373c;
      font-size: 18px;
      line-height: 1.55;
    }
    figure { margin: 30px 0; }
    figcaption {
      margin-top: 11px;
      color: var(--muted);
      font-size: 13px;
    }
    .figure-box {
      max-width: 930px;
      padding: 24px;
      border: 1px solid var(--line);
      background: #fcfcfd;
    }
    .figure-box .diagram-label {
      margin-bottom: 17px;
      font-size: 12px;
      color: var(--muted);
      letter-spacing: .08em;
      text-transform: uppercase;
    }
    .split-diagram {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 18px;
    }
    .split-pane {
      padding: 18px;
      border: 1px solid var(--line);
      background: #fff;
    }
    .split-pane h4 { margin: 0 0 15px; }
    .node-stack { display: grid; gap: 7px; }
    .node-stack span {
      display: block;
      padding: 9px 11px;
      background: var(--soft);
      border-left: 2px solid var(--ink);
      font-size: 13px;
    }
    .node-stack span.accent { border-left-color: var(--blue); background: #f1f6ff; }
    .node-stack span.purple { border-left-color: var(--purple); background: #f7f5ff; }
    .role-grid {
      display: grid;
      grid-template-columns: repeat(4, minmax(0,1fr));
      gap: 10px;
      margin: 22px 0;
    }
    .role {
      min-height: 120px;
      padding: 15px;
      border-top: 2px solid var(--ink);
      background: var(--soft);
    }
    .role b { display: block; margin-bottom: 6px; }
    .role small { color: var(--muted); line-height: 1.5; }
    .refs { counter-reset: ref; }
    .refs li { margin: 12px 0; padding-left: 5px; }
    .footer {
      padding: 42px 24px;
      border-top: 1px solid var(--line);
      color: var(--muted);
      font-size: 13px;
      text-align: center;
    }
    @media (max-width: 930px) {
      .layout { grid-template-columns: 1fr; }
      .toc { display: none; }
      .grid-3 { grid-template-columns: 1fr; }
      .role-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
    }
    @media (max-width: 650px) {
      .topbar-inner, .hero, .layout { padding-left: 18px; padding-right: 18px; }
      .topnav { max-width: 62vw; gap: 13px; }
      .hero { padding-top: 70px; }
      h1 { font-size: 50px; }
      h1 span { font-size: .48em; }
      section { padding: 55px 0; }
      .grid-2, .split-diagram { grid-template-columns: 1fr; }
      .role-grid { grid-template-columns: 1fr; }
      .metric-row { grid-template-columns: 105px 1fr 45px; }
      .callout, .formula, .figure-box { padding-left: 16px; padding-right: 16px; }
    }
    @media (prefers-reduced-motion: reduce) {
      html { scroll-behavior: auto; }
      *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
      }
    }
    @media print {
      .topbar, .toc, .progress { display: none; }
      .layout { display: block; }
      .hero { padding-top: 30px; }
      section { break-inside: auto; }
      .card, .figure-box, .lane { break-inside: avoid; }
      a { color: inherit; }
    }