:root {
    --bg: #f6f5f1;
    --ink: #1a1a1a;
    --muted: #777;
    --accent: #b08d57;
    --accent-dark: #8a6d3b;
    --panel: #fff;
    --border: #e5e2d8;
    --cream: #faf7ee;
    --takehome: #2c5f9a;
    --scenario: #8a6d3b;
    --apparatus: #6a4f12;
    --good: #2e7d32;
    --warn: #c76a00;
  }
  * { box-sizing: border-box; }
  html, body { margin: 0; padding: 0; background: var(--bg); color: var(--ink);
    font-family: 'Iowan Old Style', 'Charter', Georgia, serif; line-height: 1.6;
    font-size: 16px; }
  body { scroll-behavior: smooth; }

  header.masthead { padding: 3rem 2rem 1.5rem; text-align: center;
    background: var(--ink); color: var(--bg); }
  header.masthead h1 { margin: 0 0 0.3rem; font-size: 1.75rem; font-weight: 500;
    letter-spacing: 0.01em; }
  header.masthead p { margin: 0; color: #c9c5b8; font-style: italic; font-size: 0.95rem; }
  header.masthead .crumb { font-size: 0.78rem; color: #8a8472; letter-spacing: 0.08em;
    font-variant: small-caps; margin-bottom: 0.6rem; }

  nav.toc { position: sticky; top: 0; background: var(--ink); z-index: 50;
    padding: 0.55rem 2rem; border-bottom: 1px solid #333; }
  nav.toc ul { list-style: none; margin: 0 auto; padding: 0; display: flex;
    gap: 1.3rem; flex-wrap: wrap; max-width: 1000px; font-size: 0.82rem; }
  nav.toc a { color: #c9c5b8; text-decoration: none; padding: 0.2rem 0;
    border-bottom: 2px solid transparent; transition: all 0.15s; }
  nav.toc a:hover, nav.toc a.current { color: var(--accent);
    border-bottom-color: var(--accent); }

  main { max-width: 880px; margin: 0 auto; padding: 2.5rem 2rem 5rem; }

  section { margin: 3rem 0; }
  section:first-child { margin-top: 0; }

  h2 { font-size: 1.35rem; font-weight: 600; margin: 0 0 1rem;
    padding-bottom: 0.4rem; border-bottom: 2px solid var(--accent); }
  h3 { font-size: 1.08rem; font-weight: 600; margin: 1.5rem 0 0.5rem; color: #333; }
  h4 { font-size: 0.95rem; font-weight: 600; margin: 1.2rem 0 0.4rem; color: #555;
    font-variant: small-caps; letter-spacing: 0.08em; }

  p { margin: 0 0 0.9rem; text-align: justify; }
  p.lead { font-size: 1.05rem; color: #333; }

  .step-label { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--accent-dark); font-weight: 700;
    margin: 1.6rem 0 0.4rem; display: block; }

  /* Scenario — italic blockquote, 1-2 sentences setting a legal context */
  .scenario { background: var(--cream); border-left: 3px solid var(--scenario);
    padding: 0.9rem 1.2rem; margin: 0.6rem 0 1.4rem;
    font-style: italic; color: #3a2f12; border-radius: 0 2px 2px 0;
    font-size: 0.98rem; line-height: 1.6; }
  .scenario .lab { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--scenario); font-weight: 700;
    display: block; margin-bottom: 0.35rem; font-style: normal; }

  /* Result — 1-sentence verdict, plain words, no jargon */
  .result { background: var(--panel); border: 1px solid var(--border);
    border-left: 3px solid var(--good); border-radius: 0 2px 2px 0;
    padding: 0.7rem 1.1rem; margin: 0.6rem 0 1.2rem;
    font-size: 1rem; font-weight: 500; color: var(--ink); }
  .result .lab { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--good); font-weight: 700;
    display: block; margin-bottom: 0.3rem; }

  /* Question (alternative to scenario/result for sub-sections that frame
     the experimental question rather than a courtroom scenario) */
  .question { color: var(--ink); margin: 0 0 1.4rem; font-size: 1rem;
    line-height: 1.65; }
  .question strong { color: var(--ink); }

  /* Procedure — ordered step list with embedded numeric examples */
  ol.procedure { list-style: none; counter-reset: step;
    padding: 0; margin: 0.5rem 0 1.4rem; }
  ol.procedure > li { counter-increment: step; position: relative;
    padding-left: 2.4rem; margin-bottom: 1rem; line-height: 1.55;
    font-size: 0.95rem; }
  ol.procedure > li::before { content: counter(step); position: absolute;
    left: 0; top: 0.05rem; width: 1.7rem; height: 1.7rem;
    background: var(--cream); color: var(--accent-dark);
    border: 1px solid var(--accent); border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-weight: 700; font-size: 0.8rem; font-family: Georgia, serif; }
  ol.procedure > li .example { display: block; margin-top: 0.4rem;
    background: var(--cream); border-left: 2px solid var(--accent);
    padding: 0.4rem 0.7rem; font-size: 0.88rem; color: #444;
    border-radius: 0 2px 2px 0; }
  ol.procedure > li .example strong { color: var(--accent-dark);
    font-variant-numeric: tabular-nums; }

  .plot-frame { background: var(--panel); border: 1px solid var(--border);
    border-radius: 3px; margin: 0.8rem 0 0.4rem; }
  .plot-caption { font-size: 0.84rem; color: var(--muted);
    margin: 0.3rem 0 1.3rem; line-height: 1.5; }

  /* Meaning of numbers — what each metric measures, with its limits */
  .meaning { background: var(--panel); border: 1px solid var(--border);
    border-left: 3px solid var(--takehome); border-radius: 0 2px 2px 0;
    padding: 0.85rem 1.1rem; margin: 1.2rem 0; }
  .meaning .lab { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--takehome); font-weight: 700;
    display: block; margin-bottom: 0.4rem; }
  .meaning dl { display: grid; grid-template-columns: minmax(140px, max-content) 1fr;
    gap: 0.4rem 1rem; margin: 0; font-size: 0.92rem; }
  .meaning dt { color: var(--takehome); font-weight: 600;
    font-variant-numeric: tabular-nums;
    font-family: 'Source Code Pro', Menlo, monospace; font-size: 0.85rem; }
  .meaning dd { margin: 0; color: var(--ink); line-height: 1.55; }
  .meaning .limit { display: block; margin-top: 0.25rem;
    color: #555; font-size: 0.85rem; font-style: italic; }
  .meaning .limit::before { content: "What it does NOT say · "; font-style: normal;
    color: var(--muted); font-variant: small-caps; letter-spacing: 0.06em;
    font-weight: 700; font-size: 0.78rem; }

  /* Take-home — single-sentence pointer to Cap.4 */
  .takehome { background: var(--panel); border: 1px solid var(--border);
    border-left: 3px solid var(--takehome); border-radius: 0 2px 2px 0;
    padding: 0.85rem 1.1rem; margin: 1.2rem 0 1.6rem;
    font-size: 0.96rem; color: var(--ink); line-height: 1.55; }
  .takehome .lab { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--takehome); font-weight: 700;
    display: block; margin-bottom: 0.3rem; }

  /* Apparatus — technical L2 box, full width, bronze left border */
  .apparatus { background: var(--panel); border: 1px solid var(--border);
    border-left: 3px solid var(--apparatus); border-radius: 0 2px 2px 0;
    padding: 0.85rem 1.1rem; margin: 1.2rem 0 2rem;
    font-size: 0.88rem; color: #333; }
  .apparatus .lab { font-size: 0.66rem; font-variant: small-caps;
    letter-spacing: 0.1em; color: var(--apparatus); font-weight: 700;
    display: block; margin-bottom: 0.5rem; }
  .apparatus .formula { background: var(--cream); border-radius: 2px;
    padding: 0.45rem 0.7rem; margin: 0.4rem 0 0.6rem; text-align: center;
    font-size: 0.95em; font-family: 'Source Code Pro', Menlo, monospace; }
  .apparatus .stats { margin: 0.3rem 0; font-variant-numeric: tabular-nums; }
  .apparatus .stats strong { color: var(--apparatus); font-weight: 600; }
  .apparatus .meta { font-size: 0.8rem; color: #666; margin-top: 0.5rem;
    line-height: 1.5; }
  .apparatus code { font-family: 'Source Code Pro', Menlo, monospace;
    font-size: 0.85em; background: var(--cream); padding: 0.1em 0.35em;
    border-radius: 2px; color: #444; }
  .apparatus details > summary { cursor: pointer; outline: none;
    color: var(--apparatus); font-variant: small-caps; letter-spacing: 0.06em;
    font-weight: 700; font-size: 0.78rem; }
  .apparatus details[open] > summary { margin-bottom: 0.5rem; }

  /* Pipeline diagram (clickable 5-stage strip) */
  .pipeline { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0.5rem;
    margin: 1.5rem 0; }
  .stage { background: var(--panel); border: 1px solid var(--border);
    border-radius: 4px; padding: 0.9rem 0.7rem; text-align: center;
    cursor: pointer; transition: all 0.15s; position: relative; }
  .stage:hover { border-color: var(--accent); transform: translateY(-2px);
    box-shadow: 0 3px 8px rgba(0,0,0,0.07); }
  .stage.active { border-color: var(--accent); background: var(--cream); }
  .stage .n { display: inline-block; font-size: 0.7rem; font-weight: 700;
    color: var(--accent); background: var(--cream);
    padding: 0.08rem 0.5rem; border-radius: 10px; margin-bottom: 0.4rem; }
  .stage .label { font-size: 0.82rem; font-weight: 600; line-height: 1.3;
    color: var(--ink); }
  .stage .arrow { position: absolute; right: -0.6rem; top: 50%;
    width: 1rem; height: 1rem;
    border-top: 2px solid var(--accent); border-right: 2px solid var(--accent);
    transform: translateY(-50%) rotate(45deg); opacity: 0.5; z-index: 1; }
  .stage:last-child .arrow { display: none; }
  .stage-detail { display: none; background: var(--cream);
    border-left: 3px solid var(--accent);
    padding: 1rem 1.2rem; margin-top: 0.5rem; font-size: 0.92rem; }
  .stage-detail.open { display: block; }

  /* Verification gate badge (used on the Home page) */
  .gate-badge { display: inline-flex; align-items: center; gap: 0.6rem;
    background: var(--cream); border: 1px solid var(--good);
    color: var(--good); padding: 0.45rem 1rem; border-radius: 999px;
    font-size: 0.88rem; font-weight: 600; letter-spacing: 0.02em;
    margin: 0.6rem 0; }
  .gate-badge .dot { width: 0.55rem; height: 0.55rem; border-radius: 50%;
    background: var(--good); display: inline-block; }

  /* Anchor cards (used on Home for the three anchor results) */
  .anchor-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem; margin: 1.5rem 0 2rem; }
  .anchor-card { background: var(--panel); border: 1px solid var(--border);
    border-top: 3px solid var(--accent); border-radius: 3px;
    padding: 1rem 1.1rem 1.1rem; }
  .anchor-card .tag { font-size: 0.68rem; font-variant: small-caps;
    letter-spacing: 0.08em; color: var(--accent-dark); font-weight: 700;
    margin-bottom: 0.4rem; display: block; }
  .anchor-card h3 { margin: 0 0 0.5rem; font-size: 1rem; color: var(--ink); }
  .anchor-card p { font-size: 0.92rem; margin: 0; line-height: 1.55; }

  /* Tables */
  table.data { border-collapse: collapse; width: 100%; margin: 1rem 0;
    font-size: 0.9rem; background: var(--panel); }
  table.data th, table.data td { padding: 0.55rem 0.8rem; text-align: left;
    border-bottom: 1px solid var(--border); }
  table.data th { font-variant: small-caps; letter-spacing: 0.05em; color: #555;
    font-weight: 600; background: var(--cream);
    border-bottom: 2px solid var(--accent); }
  table.data td.num { text-align: right; font-variant-numeric: tabular-nums; }
  table.data td.strong { font-weight: 700; color: var(--accent-dark); }
  table.data tr.highlight { background: #fff8e5; }
  table.data tr.highlight td.strong { color: #6a4f12; }
  table.data tr:hover { background: var(--cream); }

  /* Highlighted single-number callout (used on Robustness Y caveat) */
  .number-callout { display: flex; align-items: baseline; gap: 0.8rem;
    background: #fff8e5; border: 1px solid #d4a017; border-radius: 4px;
    padding: 1rem 1.4rem; margin: 1.4rem 0; }
  .number-callout .value { font-size: 2.4rem; font-weight: 700;
    color: var(--accent-dark); font-variant-numeric: tabular-nums;
    line-height: 1; }
  .number-callout .descr { font-size: 0.92rem; color: #4a3f1c;
    line-height: 1.5; }
  .number-callout .descr strong { color: var(--accent-dark); }

  /* Disclaimer */
  .disclaimer { background: #fff8e5; border-left: 3px solid #d4a017;
    padding: 0.9rem 1.2rem; margin: 1.5rem 0; font-size: 0.92rem;
    color: #6a4f12; border-radius: 2px; }

  /* Linear nav (prev/next at page bottom) */
  nav.linear { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem;
    margin: 4rem 0 0.5rem; border-top: 1px solid var(--border);
    padding-top: 1.5rem; }
  nav.linear a { display: block; padding: 0.95rem 1.1rem; background: var(--panel);
    border: 1px solid var(--border); border-radius: 3px; text-decoration: none;
    color: var(--ink); transition: all 0.15s; }
  nav.linear a:hover { border-color: var(--accent); background: var(--cream);
    transform: translateY(-1px); }
  nav.linear a.prev { text-align: left; }
  nav.linear a.next { text-align: right; grid-column: 2; }
  nav.linear a .dir { display: block; font-size: 0.72rem; color: var(--muted);
    font-variant: small-caps; letter-spacing: 0.06em; margin-bottom: 0.15rem; }
  nav.linear a .lab { font-weight: 600; color: var(--accent-dark); font-size: 0.98rem; }
  nav.linear .spacer { background: transparent; border: none; }
  nav.linear.first-page { grid-template-columns: minmax(0, 480px);
    justify-content: center; }
  nav.linear.first-page a.next { grid-column: 1; text-align: center; }

  footer { text-align: center; color: var(--muted); font-size: 0.83rem;
    padding: 2rem; border-top: 1px solid var(--border); margin-top: 4rem; }
  footer code { background: var(--panel); padding: 0.1em 0.35em;
    border-radius: 2px; font-family: 'Source Code Pro', Menlo, monospace;
    font-size: 0.9em; }
  footer a { color: var(--accent-dark); }

  @media (max-width: 700px) {
    .pipeline { grid-template-columns: 1fr; }
    .stage .arrow { display: none; }
    nav.linear { grid-template-columns: 1fr; }
    nav.linear a.next { grid-column: 1; }
    main { padding: 1.5rem 1.1rem 4rem; }
    .anchor-grid { grid-template-columns: 1fr; }
    .number-callout { flex-direction: column; gap: 0.3rem; }
  }

  /* Lexicon page — input snapshots */
  details.domain-block {
    margin: 0.6rem 0 1.1rem; border: 1px solid var(--border);
    border-radius: 4px; background: var(--panel); overflow: hidden; }
  details.domain-block > summary {
    cursor: pointer; padding: 0.8rem 1.1rem; font-weight: 600;
    font-size: 1.02rem; color: var(--accent-dark);
    background: var(--cream); border-bottom: 1px solid var(--border);
    list-style: none; }
  details.domain-block > summary::-webkit-details-marker { display: none; }
  details.domain-block > summary::before {
    content: "▸ "; display: inline-block; transition: transform 0.15s;
    color: var(--accent); margin-right: 0.3rem; }
  details.domain-block[open] > summary::before { transform: rotate(90deg); }
  details.domain-block > .inner { padding: 0.6rem 1.1rem 1.1rem; }
  details.domain-block .domain-count { color: var(--muted);
    font-weight: 400; font-size: 0.9em; margin-left: 0.4rem; }

  details.term-row {
    border-bottom: 1px solid var(--border); padding: 0.4rem 0; }
  details.term-row:last-child { border-bottom: none; }
  details.term-row > summary {
    cursor: pointer; padding: 0.35rem 0.4rem; font-size: 0.95rem;
    list-style: none; display: flex; flex-wrap: wrap; gap: 0.6rem;
    align-items: baseline; }
  details.term-row > summary::-webkit-details-marker { display: none; }
  details.term-row > summary::before {
    content: "+"; display: inline-block; width: 1em; color: var(--accent);
    font-weight: 700; }
  details.term-row[open] > summary::before { content: "−"; }
  details.term-row .term-en { font-weight: 600; color: var(--ink); }
  details.term-row .term-zh { color: var(--accent-dark);
    font-family: "Noto Sans CJK SC", "Microsoft YaHei", "PingFang SC", serif; }
  details.term-row .term-meta { color: var(--muted); font-size: 0.85em;
    margin-left: auto; font-style: italic; }
  details.term-row .contexts {
    margin: 0.6rem 0 0.4rem 1.4rem; padding: 0.6rem 0.9rem;
    background: var(--cream); border-left: 3px solid var(--accent);
    border-radius: 2px; }
  details.term-row .ctx {
    margin: 0.3rem 0; line-height: 1.55; font-size: 0.9rem; }
  details.term-row .ctx .ref { font-weight: 600;
    color: var(--accent-dark); font-size: 0.85em;
    margin-right: 0.4rem; white-space: nowrap; }
  details.term-row .ctx .lang-tag {
    display: inline-block; font-size: 0.7em; font-weight: 700;
    color: var(--muted); margin-right: 0.4rem;
    border: 1px solid var(--border); padding: 0 0.3em; border-radius: 2px; }
  details.term-row .ctx.zh { font-family: "Noto Sans CJK SC",
    "Microsoft YaHei", "PingFang SC", serif; }

  /* Axis pairs view */
  .axis-pairs { display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem; margin: 0.8rem 0; }
  .axis-pairs .pairs-column {
    background: var(--cream); border-left: 3px solid var(--accent);
    padding: 0.6rem 0.9rem; border-radius: 2px; }
  .axis-pairs .pairs-column h4 {
    margin: 0 0 0.5rem; font-size: 0.95rem; color: var(--accent-dark); }
  .axis-pairs ol { margin: 0; padding-left: 1.4rem;
    font-size: 0.92rem; line-height: 1.7; }
  .axis-pairs ol li .pos { font-weight: 600; color: var(--ink); }
  .axis-pairs ol li .sep { color: var(--muted); margin: 0 0.3em; }
  .axis-pairs ol li .neg { color: var(--accent-dark); font-style: italic; }

  /* Probe template view */
  .probe-block {
    margin: 0.8rem 0; padding: 0.8rem 1rem;
    background: var(--cream); border: 1px solid var(--border);
    border-left: 3px solid var(--accent); border-radius: 2px; }
  .probe-block h4 { margin: 0 0 0.4rem; font-size: 0.98rem;
    color: var(--accent-dark); }
  .probe-block .threshold {
    font-size: 0.86rem; color: var(--muted); font-style: italic;
    margin-bottom: 0.5rem; }
  .probe-block .cats {
    font-size: 0.9rem; line-height: 1.7;
    padding: 0.4rem 0.6rem; background: #fff;
    border-radius: 2px; margin-bottom: 0.5rem; }
  .probe-block .cats .cat-idx {
    font-weight: 600; color: var(--accent); font-size: 0.82em;
    margin-right: 0.3em; }
  .probe-block .cats .expected {
    background: rgba(176, 141, 87, 0.18); padding: 0 0.2em;
    border-radius: 2px; font-weight: 600; }
  .probe-block .templates ol {
    margin: 0; padding-left: 1.5rem; font-size: 0.9rem;
    line-height: 1.7; color: var(--ink); }
  .probe-block .templates ol li { margin-bottom: 0.25rem; }
  .probe-block .templates ol li .slot {
    background: rgba(176, 141, 87, 0.25);
    padding: 0 0.25em; border-radius: 2px;
    font-style: italic; color: var(--accent-dark); }

  /* Compact control list */
  .control-grid { display: grid;
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
    gap: 0.4rem; font-size: 0.9rem; margin: 0.6rem 0; }
  .control-grid .item {
    padding: 0.3rem 0.5rem; background: var(--cream);
    border-left: 2px solid var(--accent);
    border-radius: 2px; }
  .control-grid .item .en { font-weight: 500; color: var(--ink); }
  .control-grid .item .zh { color: var(--accent-dark); margin-left: 0.3em;
    font-family: "Noto Sans CJK SC", "Microsoft YaHei", "PingFang SC", serif; }