html { -webkit-text-size-adjust: 100%; }
  body { margin: 0; }
  img { max-width: 100%; }
  :root {
    --bg: #eef2f1;
    --surface: #ffffff;
    --raised: #f7faf9;
    --tint: #e2efec;
    --text: #101819;
    --soft: #405456;
    --muted: #5f7274;
    --line: #cfdad8;
    --hair: #e0e8e6;
    --accent: #0c6b64;
    --accent-soft: #d3e8e5;
    --flag: #9a4a19;
    --shadow-sm: 0 1px 2px rgba(16, 24, 25, .05);
    --shadow-md: 0 1px 3px rgba(16, 24, 25, .06), 0 8px 24px -12px rgba(16, 24, 25, .16);
    --display: "Archivo", "Helvetica Neue", Arial, sans-serif;
    --body: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
    --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
    --measure: 68ch;
  }
  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      --bg: #0a1011;
      --surface: #121a1b;
      --raised: #16201f;
      --tint: #16292a;
      --text: #e8efed;
      --soft: #b6c5c5;
      --muted: #91a3a4;
      --line: #2b3a3b;
      --hair: #223031;
      --accent: #5bd3c6;
      --accent-soft: #1b3a38;
      --flag: #e39a63;
      --shadow-sm: 0 1px 2px rgba(0, 0, 0, .35);
      --shadow-md: 0 1px 3px rgba(0, 0, 0, .4), 0 10px 30px -14px rgba(0, 0, 0, .7);
    }
  }
  :root[data-theme="dark"] {
    --bg: #0a1011;
    --surface: #121a1b;
    --raised: #16201f;
    --tint: #16292a;
    --text: #e8efed;
    --soft: #b6c5c5;
    --muted: #91a3a4;
    --line: #2b3a3b;
    --hair: #223031;
    --accent: #5bd3c6;
    --accent-soft: #1b3a38;
    --flag: #e39a63;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .35);
    --shadow-md: 0 1px 3px rgba(0, 0, 0, .4), 0 10px 30px -14px rgba(0, 0, 0, .7);
  }

  * { box-sizing: border-box; }

  body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--body);
    font-size: 17px;
    line-height: 1.68;
    padding-inline: 20px;
    padding-block: 0 96px;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
  }
  ::selection { background: var(--accent-soft); }
  :focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

  .wrap { max-width: 1140px; margin: 0 auto; }
  .prose { max-width: var(--measure); }

  /* ---- sticky nav ---- */
  .topbar {
    position: sticky;
    top: env(safe-area-inset-top, 0px);
    z-index: 5;
    margin-inline: -20px;
    padding: 10px 20px;
    background: color-mix(in srgb, var(--bg) 88%, transparent);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--hair);
  }
  .topbar-inner {
    max-width: 1140px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 24px;
    overflow-x: auto;
    scrollbar-width: none;
  }
  .topbar-inner::-webkit-scrollbar { display: none; }
  .brand {
    font-family: var(--display);
    font-weight: 600;
    font-size: 14px;
    letter-spacing: -.01em;
    white-space: nowrap;
  }
  .topnav { display: flex; gap: 20px; white-space: nowrap; }
  .topnav a {
    font-family: var(--mono);
    font-size: 11.5px;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--muted);
    text-decoration: none;
    padding-block: 2px;
    border-bottom: 1px solid transparent;
  }
  .topnav a:hover { color: var(--text); border-bottom-color: var(--accent); }

  /* ---- masthead ---- */
  header.masthead { padding-block: 64px 40px; }
  .masthead > * { max-width: 62ch; }
  .eyebrow {
    font-family: var(--mono);
    font-size: 11.5px;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: var(--accent);
    margin: 0 0 18px;
  }
  h1 {
    font-family: var(--display);
    font-weight: 700;
    font-size: clamp(34px, 7vw, 52px);
    line-height: 1.04;
    letter-spacing: -.028em;
    margin: 0 0 20px;
    text-wrap: balance;
  }
  .lede { font-size: 19px; line-height: 1.6; margin: 0; color: var(--text); }
  .lede + .lede { margin-top: 16px; color: var(--soft); font-size: 17px; }

  /* ---- headings ---- */
  h2 {
    font-family: var(--display);
    font-weight: 600;
    font-size: clamp(24px, 3.4vw, 30px);
    line-height: 1.18;
    letter-spacing: -.02em;
    margin: 0 0 20px;
    padding-top: 28px;
    border-top: 1px solid var(--line);
    text-wrap: balance;
    scroll-margin-top: 80px;
  }
  h2:not(:first-child) { margin-top: 68px; }
  h3 {
    font-family: var(--display);
    font-weight: 600;
    font-size: 19px;
    letter-spacing: -.01em;
    line-height: 1.3;
    margin: 42px 0 12px;
    display: flex;
    align-items: center;
    gap: 12px;
    scroll-margin-top: 80px;
  }
  h3 .num {
    flex: 0 0 auto;
    display: inline-grid;
    place-items: center;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: var(--accent-soft);
    color: var(--accent);
    font-family: var(--mono);
    font-weight: 500;
    font-size: 11.5px;
    letter-spacing: 0;
  }

  /* ---- text ---- */
  p { margin: 0 0 16px; }
  .why {
    background: var(--raised);
    border-left: 3px solid var(--accent);
    border-radius: 0 6px 6px 0;
    padding: 14px 18px;
    margin: 0 0 16px;
    color: var(--soft);
    font-size: 16px;
  }
  .why b { color: var(--text); font-weight: 600; }
  ul { margin: 0 0 16px; padding-left: 22px; }
  li { margin-bottom: 9px; padding-left: 2px; }
  li::marker { color: var(--accent); }
  b, strong { font-weight: 600; }
  code {
    font-family: var(--mono);
    font-size: .86em;
    background: var(--tint);
    padding: 2px 6px;
    border-radius: 4px;
  }

  /* ---- figure ---- */
  figure { margin: 8px 0 0; }
  .scroller {
    overflow-x: auto;
    border: 1px solid var(--hair);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: var(--shadow-md);
    padding: 14px 16px;
  }
  .scroller svg { display: block; min-width: 860px; width: 100%; height: auto; }
  figcaption {
    font-size: 15px;
    line-height: 1.6;
    color: var(--soft);
    margin-top: 16px;
    max-width: var(--measure);
  }
  figcaption b { color: var(--text); }
  .hint {
    font-family: var(--mono);
    font-size: 11.5px;
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--muted);
    margin: 0 0 10px;
    max-width: var(--measure);
  }

  /* ---- diagram marks ---- */
  .box { fill: var(--surface); stroke: var(--line); stroke-width: 1.2; }
  .box.live { animation: pulse 14s linear infinite; animation-delay: calc(var(--i) * 2s); }
  .s-num { font-family: var(--mono); font-size: 11px; fill: var(--accent); letter-spacing: .08em; }
  .s-name { font-family: var(--display); font-size: 15px; font-weight: 600; fill: var(--text); }
  .s-tech { font-family: var(--mono); font-size: 10.5px; fill: var(--muted); }
  .wire { stroke: var(--line); stroke-width: 1.2; fill: none; }
  .hand { font-family: var(--mono); font-size: 10px; fill: var(--muted); }
  .aside-label { font-family: var(--mono); font-size: 10.5px; fill: var(--muted); }
  .pill { fill: var(--tint); stroke: var(--line); stroke-width: 1.2; }
  .pill-text { font-family: var(--display); font-size: 13px; font-weight: 600; fill: var(--text); }
  .drop { stroke: var(--flag); stroke-width: 1.2; fill: none; stroke-dasharray: 3 4; }
  .drop-text { font-family: var(--mono); font-size: 10px; fill: var(--flag); }
  .packet { fill: var(--accent); animation: travel 14s linear infinite; animation-delay: calc(var(--i) * 2s); opacity: 0; }
  .call { stroke: var(--accent); stroke-width: 1.4; fill: none; }
  .call-label { font-family: var(--mono); font-size: 10px; fill: var(--accent); }
  .tag { fill: none; stroke: var(--muted); stroke-width: 1; stroke-dasharray: 4 3; }
  .tag-text { font-family: var(--mono); font-size: 9.5px; fill: var(--muted); letter-spacing: .02em; }
  .packet.up { animation-name: call-out; }
  .packet.down { animation-name: call-back; }

  @keyframes call-out {
    0%, 0.9% { opacity: 0; transform: translateY(0); }
    1.7% { opacity: 1; }
    4.3% { opacity: 1; }
    5.14% { opacity: 0; transform: translateY(-52px); }
    100% { opacity: 0; transform: translateY(-52px); }
  }
  @keyframes call-back {
    0%, 5.14% { opacity: 0; transform: translateY(-52px); }
    6% { opacity: 1; }
    8% { opacity: 1; }
    9.4% { opacity: 0; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(0); }
  }
  @keyframes travel {
    0%, 8.571% { opacity: 0; transform: translateX(0); }
    10% { opacity: 1; }
    13% { opacity: 1; }
    14.286% { opacity: 0; transform: translateX(68px); }
    100% { opacity: 0; transform: translateX(68px); }
  }
  @keyframes pulse {
    0%, 8.571% { stroke: var(--accent); stroke-width: 2; fill: var(--tint); }
    12%, 100% { stroke: var(--line); stroke-width: 1.2; fill: var(--surface); }
  }
  @media (prefers-reduced-motion: reduce) {
    .packet { animation: none; opacity: 1; }
    .box.live { animation: none; }
    * { scroll-behavior: auto; }
  }

  /* ---- worked example ---- */
  .step {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: .12em;
    text-transform: uppercase;
    color: var(--accent);
    margin: 30px 0 8px;
  }
  pre {
    position: relative;
    margin: 0 0 16px;
    padding: 14px 90px 14px 16px;
    background: var(--surface);
    border: 1px solid var(--hair);
    border-radius: 10px;
    box-shadow: var(--shadow-sm);
    overflow-x: auto;
    font-family: var(--mono);
    font-size: 13px;
    line-height: 1.6;
    max-width: 940px;
    tab-size: 2;
  }
  pre code { background: none; padding: 0; font-size: inherit; }
  pre .add { color: var(--accent); }
  pre .del { color: var(--flag); }
  .note { font-size: 15px; color: var(--muted); margin: 0 0 16px; max-width: var(--measure); }

  /* ---- tables ---- */
  .tablewrap {
    overflow-x: auto;
    margin: 22px 0 10px;
    max-width: 940px;
    border: 1px solid var(--hair);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: var(--shadow-sm);
  }
  table {
    border-collapse: collapse;
    width: 100%;
    min-width: 600px;
    font-size: 15px;
    line-height: 1.55;
    font-variant-numeric: tabular-nums;
  }
  th, td {
    text-align: left;
    vertical-align: top;
    padding: 14px 18px;
    border-bottom: 1px solid var(--hair);
  }
  th {
    font-family: var(--mono);
    font-weight: 500;
    font-size: 10.5px;
    letter-spacing: .12em;
    text-transform: uppercase;
    color: var(--muted);
    background: var(--raised);
    white-space: nowrap;
  }
  td:first-child { font-weight: 600; width: 22%; }
  td:not(:first-child) { color: var(--soft); }
  tbody tr:last-child th, tbody tr:last-child td { border-bottom: none; }
  tbody tr:hover td { background: var(--raised); }

  html { scroll-behavior: smooth; }

  /* ---- hero ---- */
  .hero {
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 48px;
    align-items: center;
    padding-block: 56px 40px;
  }
  @media (max-width: 860px) {
    .hero { grid-template-columns: 1fr; gap: 36px; padding-block: 36px 28px; }
  }
  .hero h1 {
    font-family: var(--display);
    font-weight: 700;
    font-size: clamp(32px, 4.6vw, 50px);
    line-height: 1.05;
    letter-spacing: -.028em;
    margin: 0 0 18px;
    text-wrap: balance;
  }
  .hero .lede { font-size: 18px; line-height: 1.6; color: var(--soft); max-width: 52ch; margin: 0 0 26px; }
  .cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 30px; }
  .btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--display);
    font-weight: 600;
    font-size: 15px;
    padding: 12px 20px;
    border-radius: 8px;
    text-decoration: none;
    border: 1px solid transparent;
    cursor: pointer;
  }
  .btn-primary { background: var(--accent); color: var(--bg); }
  .btn-primary:hover { opacity: .92; }
  :root[data-theme="dark"] .btn-primary, :root:not([data-theme="light"]) .btn-primary { color: #06110f; }
  @media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn-primary { color: #06110f; } }
  .btn-secondary { background: var(--surface); color: var(--text); border-color: var(--line); }
  .btn-secondary:hover { border-color: var(--accent); color: var(--accent); }
  .btn svg { width: 16px; height: 16px; flex: none; }

  .stat-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding-bottom: 4px;
  }
  .stat {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 10px 16px;
    background: var(--raised);
    border: 1px solid var(--hair);
    border-radius: 8px;
    min-width: 118px;
  }
  .stat b { font-family: var(--display); font-size: 17px; font-weight: 700; letter-spacing: -.01em; }
  .stat span { font-family: var(--mono); font-size: 10.5px; letter-spacing: .04em; color: var(--muted); text-transform: uppercase; }

  /* ---- mock PR comment ---- */
  .pr-card {
    border: 1px solid var(--hair);
    border-radius: 10px;
    background: var(--surface);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    font-size: 14px;
  }
  .pr-card-head {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--hair);
    background: var(--raised);
  }
  .pr-avatar {
    width: 24px; height: 24px; border-radius: 6px; flex: none;
    background: var(--accent-soft);
    display: grid; place-items: center;
    color: var(--accent);
  }
  .pr-avatar svg { width: 14px; height: 14px; }
  .pr-card-head b { font-size: 13.5px; }
  .pr-card-head .bot-tag {
    font-family: var(--mono); font-size: 10px; letter-spacing: .04em;
    color: var(--muted); background: var(--tint); padding: 1px 6px; border-radius: 4px;
  }
  .pr-card-head .when { margin-left: auto; font-size: 12px; color: var(--muted); }
  .pr-card-body { padding: 14px 16px 16px; }
  .pr-sev-row { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; flex-wrap: wrap; }
  .pr-sev {
    font-family: var(--mono); font-size: 10.5px; font-weight: 500; letter-spacing: .06em;
    padding: 2px 8px; border-radius: 999px; text-transform: uppercase;
    color: var(--flag); border: 1px solid var(--flag);
  }
  .pr-conf { font-family: var(--mono); font-size: 11.5px; color: var(--muted); }
  .pr-title { font-weight: 600; margin: 0 0 10px; line-height: 1.45; }
  .pr-diff {
    font-family: var(--mono); font-size: 12.5px; line-height: 1.6;
    background: var(--raised); border: 1px solid var(--hair); border-radius: 6px;
    padding: 8px 12px; overflow-x: auto;
  }
  .pr-diff .add { color: var(--accent); }
  .pr-card-foot {
    padding: 10px 16px; border-top: 1px solid var(--hair);
    font-size: 12px; color: var(--muted);
  }
  .pr-card-foot code { font-size: 11px; }

  /* ---- compare ---- */
  .compare {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background: var(--hair);
    border: 1px solid var(--hair);
    border-radius: 10px;
    overflow: hidden;
    margin: 22px 0 8px;
    max-width: 940px;
  }
  @media (max-width: 640px) { .compare { grid-template-columns: 1fr; } }
  .compare-col { background: var(--surface); padding: 20px 22px; }
  .compare-col h4 {
    font-family: var(--display); font-size: 13px; font-weight: 600;
    letter-spacing: .04em; text-transform: uppercase; margin: 0 0 14px;
    color: var(--muted);
  }
  .compare-col.win h4 { color: var(--accent); }
  .compare-col ul { margin: 0; padding: 0; list-style: none; }
  .compare-col li {
    display: flex; gap: 9px; align-items: flex-start;
    font-size: 14.5px; line-height: 1.5; margin-bottom: 12px; color: var(--soft);
  }
  .compare-col li:last-child { margin-bottom: 0; }
  .compare-col .mark { flex: none; width: 16px; height: 16px; margin-top: 2px; }
  .compare-col.base .mark { color: var(--flag); }
  .compare-col.win .mark { color: var(--accent); }
  .compare-col.win li { color: var(--text); }

  /* ---- feature grid ---- */
  .feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
    margin: 22px 0 8px;
  }
  .feature-card {
    border: 1px solid var(--hair);
    border-radius: 10px;
    background: var(--surface);
    padding: 20px 20px 22px;
    box-shadow: var(--shadow-sm);
  }
  .feature-card .f-num {
    font-family: var(--mono); font-size: 11px; color: var(--accent);
    letter-spacing: .08em; margin-bottom: 10px;
  }
  .feature-card h4 {
    font-family: var(--display); font-size: 16.5px; font-weight: 600;
    margin: 0 0 8px; letter-spacing: -.01em;
  }
  .feature-card p { font-size: 14.5px; color: var(--soft); margin: 0; line-height: 1.55; }
  .feature-card code { font-size: .84em; }

  /* ---- copyable code block ----
     One script (assets/docs.js) finds every <pre> on every page and drops
     a button in, so a code block is copyable because it is a code block --
     nothing upstream has to remember to wrap it or wire a target id. */
  .copy-btn {
    position: absolute; top: 10px; right: 10px;
    font-family: var(--mono); font-size: 11px; letter-spacing: .03em;
    padding: 5px 10px; border-radius: 6px;
    background: var(--surface); border: 1px solid var(--hair); color: var(--muted);
    cursor: pointer;
  }
  .copy-btn:hover { color: var(--text); border-color: var(--accent); }
  .copy-btn:disabled { cursor: default; color: var(--accent); border-color: var(--accent); }

  /* ---- docs layout ---- */
  .doc-layout {
    display: grid;
    grid-template-columns: 216px minmax(0, 1fr);
    gap: 52px;
    align-items: start;
    padding-block: 40px 0;
  }
  /* a page with enough h2's to jump between gets a third rail; one that
     doesn't (or is itself a list of collapsed questions) stays 2-column */
  .doc-layout.with-toc { grid-template-columns: 216px minmax(0, 1fr) 200px; }
  @media (max-width: 1180px) {
    .doc-layout.with-toc { grid-template-columns: 216px minmax(0, 1fr); }
    .toc { display: none; }
  }
  @media (max-width: 880px) {
    .doc-layout { grid-template-columns: 1fr; gap: 28px; padding-block: 28px 0; }
    .toc { display: none; }
  }
  .sidebar { position: sticky; top: 76px; }
  @media (max-width: 880px) {
    .sidebar {
      position: static;
      border: 1px solid var(--hair);
      border-radius: 10px;
      background: var(--surface);
      padding: 16px 18px;
    }
  }
  .sidebar h5 {
    font-family: var(--mono);
    font-size: 10.5px;
    letter-spacing: .12em;
    text-transform: uppercase;
    color: var(--muted);
    margin: 0 0 12px;
    font-weight: 500;
  }
  .sidebar ul { list-style: none; margin: 0 0 24px; padding: 0; }
  .sidebar li { margin: 0 0 2px; }
  .sidebar a {
    display: block;
    padding: 6px 10px;
    margin-left: -10px;
    border-radius: 6px;
    font-size: 14.5px;
    color: var(--soft);
    text-decoration: none;
    line-height: 1.4;
  }
  .sidebar a:hover { background: var(--raised); color: var(--text); }
  .sidebar a.current { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

  .doc-body { max-width: var(--measure); }
  .doc-body > .tablewrap, .doc-body > .code-box { max-width: 100%; }
  .doc-body h1 {
    font-family: var(--display);
    font-weight: 700;
    font-size: clamp(28px, 4vw, 38px);
    line-height: 1.12;
    letter-spacing: -.025em;
    margin: 0 0 14px;
  }
  .doc-lede { font-size: 18px; line-height: 1.6; color: var(--soft); margin: 0 0 8px; }
  .doc-body h2 {
    position: relative;
    margin-top: 48px;
    padding-top: 24px;
    font-size: clamp(21px, 2.6vw, 25px);
  }
  .doc-body h3 {
    display: block;
    font-size: 17px;
    margin: 30px 0 10px;
  }
  .h-anchor {
    margin-left: 8px;
    font-weight: 400;
    font-size: .75em;
    color: var(--muted);
    text-decoration: none;
    opacity: 0;
    transition: opacity .15s;
  }
  h2:hover > .h-anchor, summary:hover .h-anchor, .h-anchor:focus-visible { opacity: 1; }
  .h-anchor:hover { color: var(--accent); }
  .doc-nextprev {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    margin-top: 56px;
    padding-top: 22px;
    border-top: 1px solid var(--hair);
    font-size: 15px;
  }
  .doc-nextprev a { color: var(--accent); text-decoration: none; }
  .doc-nextprev a:hover { text-decoration: underline; }
  .doc-body a { color: var(--accent); }

  .callout {
    border: 1px solid var(--hair);
    border-left: 3px solid var(--flag);
    background: var(--raised);
    border-radius: 0 8px 8px 0;
    padding: 14px 18px;
    margin: 0 0 18px;
    font-size: 15px;
    color: var(--soft);
  }
  .callout b { color: var(--text); }
  .callout.ok { border-left-color: var(--accent); }

  /* ---- on-this-page rail ---- */
  .toc { position: sticky; top: 76px; font-size: 13.5px; }
  .toc h5 {
    font-family: var(--mono);
    font-size: 10.5px;
    letter-spacing: .12em;
    text-transform: uppercase;
    color: var(--muted);
    margin: 0 0 12px;
    font-weight: 500;
  }
  .toc ul { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--hair); }
  .toc li { margin: 0; }
  .toc a {
    display: block;
    padding: 5px 0 5px 14px;
    margin-left: -1px;
    border-left: 2px solid transparent;
    color: var(--muted);
    text-decoration: none;
    line-height: 1.4;
  }
  .toc a:hover { color: var(--text); }
  .toc a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 500; }

  /* ---- collapsed Q&A: minimal until asked, full answer on demand ---- */
  details {
    border: 1px solid var(--hair);
    border-radius: 10px;
    background: var(--surface);
    margin: 0 0 10px;
  }
  details[open] { box-shadow: var(--shadow-sm); }
  details + h2, details + .callout { margin-top: 40px; }
  details summary {
    position: relative;
    list-style: none;
    cursor: pointer;
    padding: 16px 46px 16px 18px;
    font-family: var(--display);
    font-weight: 600;
    font-size: 16.5px;
    line-height: 1.4;
  }
  details summary::marker { content: ""; }
  details summary::-webkit-details-marker { display: none; }
  details summary::after {
    content: "+";
    position: absolute;
    right: 18px;
    top: 16px;
    font-family: var(--mono);
    font-size: 18px;
    line-height: 1.3;
    color: var(--muted);
  }
  details[open] summary::after { content: "\2212"; }
  details summary:hover::after { color: var(--accent); }
  details .details-body { padding: 0 18px 18px; color: var(--soft); }
  details .details-body > :last-child { margin-bottom: 0; }
  details .details-body > :first-child { margin-top: 0; }

  table.compact { font-size: 14px; }
  table.compact td:first-child { width: auto; white-space: nowrap; font-family: var(--mono); font-weight: 400; font-size: 13px; }

  /* ---- design comparison: where the decisions get made ---- */
  .lanes {
    margin: 22px 0 8px;
    max-width: 940px;
    padding: 16px 22px 8px;
    border: 1px solid var(--hair);
    border-radius: 12px;
    background: var(--surface);
    box-shadow: var(--shadow-sm);
  }
  .lanes-axis {
    display: flex;
    justify-content: space-between;
    margin-left: 188px;
    padding-bottom: 10px;
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: .1em;
    text-transform: uppercase;
    color: var(--muted);
  }
  .lane {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    column-gap: 18px;
    align-items: center;
    padding: 13px 0 14px;
    border-top: 1px solid var(--hair);
  }
  .lane-name { font-family: var(--display); font-weight: 600; font-size: 16px; letter-spacing: -.01em; }
  .lane.ours .lane-name { color: var(--accent); }
  .lane-track {
    position: relative;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(90deg, var(--accent-soft), var(--tint) 50%, color-mix(in srgb, var(--flag) 32%, transparent));
  }
  .lane-dot {
    position: absolute;
    top: 50%;
    width: 16px;
    height: 16px;
    margin: -8px 0 0 -8px;
    border-radius: 50%;
    background: var(--muted);
    border: 2px solid var(--surface);
  }
  .lane.ours .lane-dot { background: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
  .lane-desc { grid-column: 2; margin: 10px 0 0; font-size: 14.5px; line-height: 1.55; color: var(--soft); }
  @media (max-width: 640px) {
    .lanes { padding: 14px 16px 6px; }
    .lanes-axis { margin-left: 0; }
    .lane { grid-template-columns: 1fr; row-gap: 10px; }
    .lane-desc { grid-column: 1; margin-top: 4px; }
  }

  .check-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
    gap: 14px;
    margin: 20px 0 8px;
    max-width: 940px;
  }
  .check-card {
    padding: 16px 18px 18px;
    border: 1px solid var(--hair);
    border-radius: 10px;
    background: var(--surface);
    box-shadow: var(--shadow-sm);
  }
  .check-card.ours { border-color: var(--accent); background: var(--raised); }
  .check-card h4 { margin: 0 0 4px; font-family: var(--display); font-size: 15.5px; letter-spacing: -.01em; }
  .check-card .how {
    margin: 0 0 9px;
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--accent);
  }
  .check-card.unknown .how { color: var(--muted); }
  .check-card p:not(.how) { margin: 0; font-size: 14.5px; line-height: 1.55; color: var(--soft); }

  .feature-grid.narrow { max-width: 940px; }
  .sources { max-width: var(--measure); margin: 18px 0 0; font-size: 13.5px; line-height: 1.6; color: var(--muted); }
  .sources a { color: var(--accent); }