.head { padding: 80px 0 44px; }
  .crumb { font-size: 14.5px; color: var(--muted); }
  .crumb a { color: var(--mark); }
  .head-grid { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 72px; align-items: end; margin-top: 24px; }
  .head h1 { font-family: var(--serif); font-weight: 340; font-size: clamp(48px, 6vw, 86px); line-height: .98; letter-spacing: -.035em; margin: 0; text-wrap: balance; }
  .head h1 i { color: var(--muted); font-weight: 300; }
  .head .std { margin-top: 26px; max-width: 34em; }
  .facts { margin: 0; border-top: 1px solid var(--line-2); font-size: 14.5px; }
  .facts div { display: grid; grid-template-columns: 5.2em 1fr; gap: 12px; padding: 10px 0; border-bottom: 1px solid var(--line); }
  .facts dt { color: var(--faint); }
  .facts dd { margin: 0; color: var(--text); line-height: 1.45; }
  .cover [data-cover] { aspect-ratio: 24 / 7; border-radius: 4px; box-shadow: 0 0 0 1px var(--line), 0 60px 120px -60px rgba(232,96,63,.35); }
  .own-sum { margin-top: 56px; }
  .own-sum > p { font-size: 13.5px; color: var(--faint); margin-bottom: 12px; }

  .body { display: grid; grid-template-columns: 210px minmax(0, 680px) 1fr; gap: 0 56px; padding: 96px 0 40px; }
  .rail { grid-column: 1; grid-row: 1 / span 40; align-self: start; font-size: 14px; }
  .rail .role { padding-bottom: 16px; margin-bottom: 16px; border-bottom: 1px solid var(--line); color: var(--muted); line-height: 1.5; }
  .rail .role b { display: block; color: var(--text); font-weight: 560; }
  .rail a { display: block; padding: 5px 0 5px 14px; color: var(--muted); border-left: 1px solid var(--line); transition: color .15s, border-color .15s; }
  .rail a:hover, .rail a.on { color: var(--text); border-left-color: var(--mark); }
  @media (min-width: 1100px) and (min-height: 720px) { .rail { position: sticky; top: 104px; max-height: calc(100vh - 128px); overflow: auto; } }
  .sec { grid-column: 2; padding-bottom: 72px; }
  .sec h2 { font-family: var(--serif); font-weight: 360; font-size: clamp(32px, 3vw, 42px); letter-spacing: -.025em; line-height: 1.08; margin-bottom: 20px; }
  .sec h2 span { display: block; font-family: var(--ui); font-size: 14px; color: var(--mark); letter-spacing: 0; margin-bottom: 10px; }
  .sec h3.sub { font-size: 17px; font-weight: 600; margin: 28px 0 8px; }
  .sec p { color: var(--vellum); font-size: 17.5px; line-height: 1.75; }
  .sec p + p { margin-top: 18px; }
  .sec .aside { margin-top: 22px; font-size: 15px; color: var(--muted); border-left: 2px solid var(--mark); padding: 2px 0 2px 16px; }
  .side { grid-column: 3; font-size: 14px; color: var(--muted); line-height: 1.6; align-self: start; padding-top: 58px; }
  .side b { display: block; color: var(--text); font-weight: 560; margin-bottom: 4px; }
    .wide { grid-column: 1 / -1; position: relative; z-index: 2; background: var(--bg); padding: 8px 0 80px; margin: 0; }
  .wide .cap { margin-top: 14px; }
  .wide.tight { padding-bottom: 36px; }
    .fig-steps li.is-opt > div { border-left: 1.5px dashed var(--f-opt); padding-left: 12px; }
  .fig-steps li.is-opt b::after { content: " · optional model"; font-weight: 400; color: var(--faint); font-size: 14px; }

    .checks { display: grid; grid-template-columns: repeat(5, 1fr); margin: 28px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line-2); border-bottom: 1px solid var(--line-2); }
  .checks li { padding: 16px 18px 18px; border-left: 1px solid var(--line); font-size: 14.5px; color: var(--muted); line-height: 1.5; }
  .checks li:first-child { border-left: 0; padding-left: 0; }
  .checks b { display: block; color: var(--text); font-size: 15px; font-weight: 600; margin-bottom: 6px; }
  .checks b::before { content: "✓"; color: var(--mark); margin-right: 8px; }
  .checks-cap { margin-top: 10px; font-size: 13.5px; color: var(--faint); }

  .decisions { counter-reset: d; margin-top: 8px; padding: 0; list-style: none; }
  .decisions li { counter-increment: d; display: grid; grid-template-columns: 52px 1fr; padding: 24px 0; border-top: 1px solid var(--line); }
  .decisions li::before { content: counter(d, decimal-leading-zero); font-family: var(--serif); font-size: 26px; color: var(--mark); line-height: 1; }
  .decisions h3 { font-size: 18px; font-weight: 600; letter-spacing: -.01em; margin: 0 0 8px; }
  .decisions dl { display: grid; grid-template-columns: 6.5em 1fr; gap: 6px 14px; margin: 0; font-size: 15.5px; line-height: 1.6; }
  .decisions dt { color: var(--faint); }
  .decisions dd { margin: 0; color: var(--vellum); }
  .decisions .tag { font-size: 12.5px; color: var(--mark); margin-left: 8px; font-weight: 500; }
  .list { margin-top: 18px; padding: 0; list-style: none; }
  .list li { position: relative; padding: 9px 0 9px 22px; border-top: 1px solid var(--line); color: var(--vellum); font-size: 16.5px; line-height: 1.6; }
  .list li::before { content: ""; position: absolute; left: 0; top: 20px; width: 9px; height: 1px; background: var(--mark); }
  .perf { display: grid; grid-template-columns: 1fr 1fr; margin-top: 22px; border-top: 1px solid var(--line-2); border-bottom: 1px solid var(--line-2); }
  .perf > div { padding: 16px 20px 18px 0; }
  .perf > div + div { padding-left: 20px; border-left: 1px solid var(--line); }
  .perf h3 { font-size: 12.5px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin: 0 0 8px; }
  .perf p { font-size: 15.5px; line-height: 1.6; }
  .perf small { display: block; margin-top: 8px; font-size: 13.5px; color: var(--faint); line-height: 1.5; }
  .tech { display: grid; grid-template-columns: 11em 1fr; margin-top: 8px; }
  .tech dt, .tech dd { padding: 12px 0; border-top: 1px solid var(--line); margin: 0; font-size: 15.5px; }
  .tech dt { color: var(--text); font-weight: 560; }
  .tech dd { color: var(--muted); }
  .next { display: grid; grid-template-columns: 1fr auto; gap: 16px; align-items: end; margin: 40px 0 120px; padding-top: 26px; border-top: 1px solid var(--text); }
  .next small { font-size: 14px; color: var(--mark); }
  .next strong { display: block; font-family: var(--serif); font-weight: 350; font-size: clamp(32px, 4vw, 54px); letter-spacing: -.03em; line-height: 1; margin-top: 8px; }
  .next .links { display: flex; gap: 24px; }

  @media (max-width: 1180px) { .head-grid { grid-template-columns: minmax(0, 1fr) 300px; gap: 48px; } }
  @media (max-width: 1099px) {
    .body { grid-template-columns: minmax(0, 1fr); padding-top: 64px; }
    .rail { grid-column: 1; grid-row: auto; display: flex; flex-wrap: nowrap; overflow-x: auto; gap: 6px; margin-bottom: 44px; position: static; scrollbar-width: none; }
    .rail .role { display: none; }
    .rail a { border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; white-space: nowrap; }
    .sec, .wide { grid-column: 1; }
    .side { grid-column: 1; padding: 0 0 64px; }
    .checks { grid-template-columns: repeat(3, 1fr); }
    .checks li:nth-child(4) { border-left: 0; padding-left: 0; }
    .checks li:nth-child(n+4) { border-top: 1px solid var(--line); }
  }
  @media (max-width: 900px) {
    .head { padding: 44px 0 32px; }
    .head-grid { grid-template-columns: 1fr; gap: 30px; margin-top: 18px; }
    .head h1 { font-size: clamp(40px, 11vw, 48px); }
    .facts div { grid-template-columns: 5.6em 1fr; }
    .cover [data-cover] { aspect-ratio: 16 / 9; }
    .own-sum { margin-top: 40px; }
    .sec { padding-bottom: 56px; } .wide { padding-bottom: 56px; }
    .sec p { font-size: 16.5px; }
    .checks { grid-template-columns: 1fr; border-bottom: 0; }
    .checks li, .checks li:first-child, .checks li:nth-child(4) { border-left: 0; padding: 12px 0; border-bottom: 1px solid var(--line); border-top: 0; }
    .checks b { display: inline; margin: 0 6px 0 0; }
    .decisions li { grid-template-columns: 40px 1fr; }
    .decisions dl, .tech { grid-template-columns: 1fr; }
    .decisions dd { margin-bottom: 6px; }
    .perf { grid-template-columns: 1fr; border-bottom: 0; }
    .perf > div, .perf > div + div { padding: 14px 0; border-left: 0; border-bottom: 1px solid var(--line); }
    .tech dd { border-top: 0; padding-top: 0; }
    .next { grid-template-columns: 1fr; margin-bottom: 80px; }
  }