/* =====================================================================
   /engine/ : agents + simulation. Page styles (prefix eng-).
   Colour roles on this page:
   amber   = the queue / "look here"     orange = lab, heavy jobs
   crimson = team, failure path          purple(-ink) = ingestion, kernel points
   The four persona colours are the four brand stripes, in brand order.
   ===================================================================== */

.page-engine { --eng-label: 220px; --eng-gap: 16px; }
.page-engine .section { padding-block: clamp(56px, 6.5vw, 100px); }
.page-engine .section h2 + .lead, .page-engine .section h2 + p.lead { margin-top: clamp(28px, 3.4vw, 48px); }
.page-engine .section h2 { text-wrap: balance; }

/* ---------- shared bits ---------- */
.eng-figlabel { font: 500 11.5px/1.4 var(--font-mono); letter-spacing: 0.03em; color: var(--ink-2); text-transform: uppercase; }
.eng-figlabel--muted { color: var(--ink-3); }
.eng-cap { font: 400 12.5px/1.6 var(--font-mono); color: var(--ink-3); max-width: 96ch; margin-top: 18px; }
.eng-cap .chips { display: flex; margin-top: 12px; }
.eng-srcrow { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 28px; }
.eng-bullets { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.eng-bullets li { position: relative; padding-left: 18px; }
.eng-bullets li::before { content: ""; position: absolute; left: 0; top: 0.68em; width: 8px; height: 2px; background: var(--orange); }
.eng-sub { font: 500 12px/1.3 var(--font-mono); text-transform: uppercase; letter-spacing: 0.03em; color: var(--amber); margin: 0 0 12px; }
.eng-sub:not(:first-child) { margin-top: 28px; }
.eng-prose-sm { font: 400 15px/1.65 var(--font-text); color: var(--ink-2); }
.eng-prose-sm > * + * { margin-top: 0.9em; }
.eng-prose-sm ul { padding-left: 1.2em; }
.eng-prose-sm li + li { margin-top: 0.35em; }
.eng-prose-sm code { color: var(--amber-ink); }
.eng-two { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 64px); }
@media (max-width: 860px) { .eng-two { grid-template-columns: 1fr; } }

/* ---------- hero ---------- */
.eng-hero { position: relative; isolation: isolate; overflow: hidden; background: var(--bg-deep); min-height: min(100svh - var(--header-h), 980px); display: flex; }
.eng-hero--noimg { background: radial-gradient(70% 80% at 80% 60%, rgba(100, 13, 95, 0.55), transparent 70%), radial-gradient(40% 50% at 85% 70%, rgba(235, 91, 0, 0.3), transparent 70%), var(--bg-deep); }
.eng-hero__media { position: absolute; inset: 0; z-index: -2; }
.eng-hero__media img { width: 100%; height: 100%; object-fit: cover; object-position: 60% 40%; }
.eng-hero::before { content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background:
    linear-gradient(90deg, rgba(18, 18, 18, 0.88) 0%, rgba(18, 18, 18, 0.62) 32%, rgba(18, 18, 18, 0) 60%),
    linear-gradient(180deg, rgba(18, 18, 18, 0.35) 0%, rgba(18, 18, 18, 0) 30%, rgba(18, 18, 18, 0) 55%, var(--bg) 100%); }
.eng-hero__inner { position: relative; display: flex; flex-direction: column; padding-top: 28px; padding-bottom: clamp(52px, 5vw, 64px); }
.eng-hero__copy { margin-top: clamp(24px, 7vh, 112px); max-width: 1100px; }
.eng-hero__title { font: 400 clamp(58px, 10.6vw, 184px)/0.86 var(--font-display); letter-spacing: var(--track-display); margin-left: -0.04em; text-wrap: balance; }
.eng-hero__lead { font: 400 var(--fs-lead)/1.38 var(--font-text); color: var(--ink-2); max-width: 36ch; margin-top: clamp(24px, 3vw, 40px); letter-spacing: -0.012em; }
.eng-hero__lead strong { color: var(--ink); font-weight: 400; }
.eng-readouts { list-style: none; margin: clamp(48px, 8vh, 120px) 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border-top: 1px solid var(--line-2); }
.eng-readouts__item { display: grid; align-content: start; gap: 8px; padding: 18px 24px 0 0; }
.eng-readouts__item + .eng-readouts__item { padding-left: 20px; border-left: 1px solid var(--line); }
.eng-readouts__k { font: 500 11.5px/1 var(--font-mono); letter-spacing: 0.03em; color: var(--amber); }
.eng-readouts__v { font: 400 clamp(32px, 3.6vw, 56px)/0.95 var(--font-display); letter-spacing: -0.045em; white-space: nowrap; }
.eng-readouts__x { color: var(--ink-3); margin: 0 0.06em; font-size: 0.7em; vertical-align: 0.08em; }
.eng-readouts__n { font: 400 12.5px/1.5 var(--font-mono); color: var(--ink-2); }
.eng-hero__start { display: flex; align-items: center; gap: 10px; margin-top: 28px; color: var(--ink-2); font-size: 12.5px; }
.eng-hero__dot { width: 8px; height: 8px; border-radius: 50%; background: var(--amber); box-shadow: 0 0 0 0 rgba(255, 178, 0, 0.6); flex: none; }
.eng-hero .crumbs { margin-bottom: 0; }
@media (max-width: 900px) {
  .eng-readouts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .eng-readouts__item:nth-child(3) { padding-left: 0; border-left: 0; }
  .eng-readouts__item:nth-child(n + 3) { border-top: 1px solid var(--line); margin-top: 18px; }
}
@media (max-width: 640px) {
  .eng-hero { min-height: 0; }
  .eng-hero__media img { object-position: 72% 50%; }
  .eng-hero::before { background: linear-gradient(180deg, rgba(18, 18, 18, 0.55) 0%, rgba(18, 18, 18, 0.35) 40%, rgba(18, 18, 18, 0.85) 75%, var(--bg) 100%); }
  .eng-hero__copy { margin-top: 48px; }
  .eng-readouts { margin-top: 56px; }
  .eng-readouts__item { padding-right: 10px; }
  .eng-readouts__item + .eng-readouts__item { padding-left: 14px; }
  .eng-readouts__item:nth-child(3) { padding-left: 0; }
}

/* ---------- in-page index (sticky) ---------- */
.eng-index { position: sticky; top: calc(var(--header-h) + 3px); z-index: 50; background: color-mix(in srgb, var(--bg) 88%, transparent); -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.eng-index__list { display: flex; gap: clamp(12px, 2vw, 28px); overflow-x: auto; scrollbar-width: none; list-style: none; margin: 0; padding: 0; }
.eng-index__list::-webkit-scrollbar { display: none; }
.eng-index a { display: flex; align-items: baseline; gap: 7px; padding: 13px 0 12px; font: 400 12px/1 var(--font-mono); color: var(--ink-3); text-decoration: none; white-space: nowrap; border-bottom: 2px solid transparent; transition: color 0.2s, border-color 0.2s; }
.eng-index a span { color: var(--ink-3); font-size: 10.5px; }
.eng-index a:hover { color: var(--ink); }
.eng-index a.is-current { color: var(--ink); border-bottom-color: var(--amber); }
.eng-index a.is-current span { color: var(--amber); }

/* ---------- 01 thesis ---------- */
.eng-thesis__title { margin-left: -0.04em; }
.eng-thesis__intro { margin-top: clamp(24px, 3vw, 40px); margin-bottom: clamp(32px, 4vw, 56px); }
.eng-thesis__bars .statbar { min-height: clamp(76px, 7.4vw, 104px); }
.eng-thesis__bars .statbar__label { display: block; }
.eng-math { display: block; margin-top: 8px; font: 400 clamp(11px, 0.95vw, 13.5px)/1.35 var(--font-mono); letter-spacing: 0; opacity: 0.92; }
.eng-thesis__bars .statbar--amber, .eng-thesis__bars .statbar--amber .est { color: #121212; }
.eng-thesis__bars .statbar--amber .est { border-color: rgba(0, 0, 0, 0.35); }
.eng-thesis__bars .statbar .est { color: inherit; border-color: rgba(255, 255, 255, 0.5); vertical-align: 0.3em; }
.eng-thesis__bars .statbar--orange, .eng-thesis__bars .statbar--orange .est { color: var(--on-orange); }
.eng-thesis__bars .statbar--orange .est { border-color: rgba(0, 0, 0, 0.35); }

/* ---------- 02 parallel ---------- */
.eng-par__lead { margin-top: clamp(24px, 3vw, 40px); }
.eng-mech { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(20px, 3vw, 48px); margin: clamp(40px, 5vw, 64px) 0 clamp(32px, 4vw, 56px); }
.eng-mech__item { border-top: 1px solid var(--line-2); padding-top: 20px; display: grid; align-content: start; gap: 12px; }
.eng-mech__n { font: 500 12px/1 var(--font-mono); color: var(--amber); }
.eng-mech__h { font: 400 clamp(24px, 2.3vw, 34px)/1.05 var(--font-display); letter-spacing: -0.035em; }
.eng-mech__item p { font: 400 15.5px/1.6 var(--font-text); color: var(--ink-2); }
.eng-mech__item strong { color: var(--ink); font-weight: 700; }
@media (max-width: 900px) { .eng-mech { grid-template-columns: 1fr; } }

.eng-lanes { background: var(--bg-deep); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: clamp(18px, 2.4vw, 32px); }
.eng-lanes__head { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px; margin-bottom: 18px; }
.eng-lanes__grid { position: relative; padding-bottom: 30px; }
.eng-lane { display: grid; grid-template-columns: var(--eng-label) minmax(0, 1fr); gap: var(--eng-gap); align-items: center; padding: 14px 0; border-top: 1px solid var(--line); position: relative; }
.eng-lane--axis { border-top: 0; padding: 0 0 8px; }
.eng-lane__label { display: grid; gap: 3px; position: relative; z-index: 2; }
.eng-lane__tag { font: 500 10.5px/1 var(--font-mono); color: var(--ink-3); letter-spacing: 0.04em; }
.eng-lane__tag--amber { color: var(--amber); }
.eng-lane__tag--orange { color: var(--orange-ink); }
.eng-lane__tag--crimson { color: var(--crimson-ink); }
.eng-lane__name { font: 400 21px/1.1 var(--font-display); letter-spacing: -0.03em; }
.eng-lane__sub { font: 400 11.5px/1.4 var(--font-mono); color: var(--ink-3); }
.eng-lane__track { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: 3px; row-gap: 4px; align-items: end; min-height: 40px; position: relative; z-index: 1; }
.eng-lane__track--rows { grid-template-rows: auto auto auto auto auto; align-items: center; }
.eng-axis { min-height: 0; }
.eng-axis__m { display: grid; gap: 2px; font: 400 10.5px/1 var(--font-mono); color: var(--ink-3); padding-left: 4px; border-left: 1px solid var(--line); }
.eng-axis__m b { font-weight: 500; color: var(--ink-2); }
.eng-axis__m i { font-style: normal; }
.eng-lanes__divider { display: flex; align-items: center; gap: 14px; padding: 16px 0 6px; border-top: 1px solid var(--line); font: 500 11.5px/1 var(--font-mono); text-transform: uppercase; letter-spacing: 0.03em; color: var(--amber); }
.eng-lanes__divider::after { content: ""; flex: 1; height: 1px; background: linear-gradient(90deg, var(--amber), transparent); opacity: 0.5; }

.eng-seg { display: flex; align-items: center; min-width: 0; height: 28px; padding: 0 8px; border-radius: 3px; font: 500 11px/1 var(--font-mono); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transform-origin: left center; }
.eng-seg--conv { color: var(--ink-2); background: repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.16) 0 5px, rgba(255, 255, 255, 0.04) 5px 11px); box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.14); }
.eng-seg--fade { background: linear-gradient(90deg, rgba(255, 255, 255, 0.12), transparent); box-shadow: none; color: var(--ink-3); }
.eng-seg--queue { height: calc(14px + var(--h) * 30px); background: var(--amber); color: #121212; border-radius: 3px 3px 0 0; }
.eng-seg__txt b { font-weight: 700; margin-right: 4px; }
.eng-ticks { grid-row: 2; height: 9px; background: repeating-linear-gradient(90deg, rgba(255, 178, 0, 0.85) 0 1px, transparent 1px calc(100% / 52)); }
.eng-seg--phase { height: 18px; font-size: 10.5px; font-weight: 400; color: var(--ink-2); background: rgba(235, 91, 0, 0.16); border-left: 2px solid var(--orange); border-radius: 0 3px 3px 0; }
.eng-seg--gen { height: 22px; background: var(--orange); color: var(--on-orange); }
.eng-dec { width: 8px; height: 8px; justify-self: center; transform: rotate(45deg); background: var(--orange-ink); margin-top: 3px; }
.eng-seg--team { height: calc(8px + var(--h) * 30px); justify-content: center; background: var(--crimson); color: #fff; padding: 0; border-radius: 3px 3px 0 0; align-items: flex-start; padding-top: 4px; }
.eng-seg--team b { font-weight: 500; }
.eng-lanes__markers { position: absolute; inset: 0; display: grid; grid-template-columns: var(--eng-label) minmax(0, 1fr); gap: var(--eng-gap); pointer-events: none; }
.eng-lanes__markers .eng-lane__track { align-items: stretch; height: 100%; }
.eng-marker { grid-row: 1; border-left: 1px dashed rgba(255, 178, 0, 0.7); position: relative; margin-left: -2px; }
.eng-marker i { position: absolute; bottom: 4px; left: 6px; font: 500 10px/1.2 var(--font-mono); font-style: normal; color: var(--amber); white-space: nowrap; background: var(--bg-deep); padding: 2px 4px; }

/* lanes animate once on reveal: parallel lanes fill together, the conventional lane steps one block at a time */
.js .eng-lanes[data-reveal] .eng-seg, .js .eng-lanes[data-reveal] .eng-ticks, .js .eng-lanes[data-reveal] .eng-dec { transform: scaleX(0); opacity: 0; transition: transform 0.9s var(--ease-out), opacity 0.4s; }
.js .eng-lanes[data-reveal] .eng-seg--conv { transition-delay: calc(0.35s + var(--i) * 0.55s); }
.js .eng-lanes[data-reveal] .eng-seg--queue, .js .eng-lanes[data-reveal] .eng-ticks { transition-delay: 0.35s; transition-duration: 1.6s; }
.js .eng-lanes[data-reveal] .eng-seg--phase, .js .eng-lanes[data-reveal] .eng-seg--gen { transition-delay: calc(0.45s + var(--i) * 0.12s); }
.js .eng-lanes[data-reveal] .eng-dec { transition-delay: 0.9s; }
.js .eng-lanes[data-reveal] .eng-seg--team { transform: scaleY(0); transform-origin: bottom; transition-delay: calc(0.4s + var(--i) * 0.05s); }
.js .eng-lanes[data-reveal].is-in .eng-seg, .js .eng-lanes[data-reveal].is-in .eng-ticks, .js .eng-lanes[data-reveal].is-in .eng-dec { transform: none; opacity: 1; }
.js .eng-lanes[data-reveal].is-in .eng-dec { transform: rotate(45deg); }
.js .eng-lanes[data-reveal].is-in .eng-seg--fade { opacity: 1; }
.eng-seg .s { display: none; }

@media (max-width: 760px) {
  .page-engine { --eng-label: 0px; --eng-gap: 0px; }
  .eng-lane { grid-template-columns: minmax(0, 1fr); gap: 8px; }
  .eng-lane--axis .eng-lane__label, .eng-lanes__markers > .eng-lane__label { display: none; }
  .eng-lane__label { grid-template-columns: auto 1fr; align-items: baseline; column-gap: 10px; }
  .eng-lane__name { font-size: 18px; }
  .eng-lane__sub { grid-column: 1 / -1; }
  .eng-lanes__markers { grid-template-columns: minmax(0, 1fr); }
  .eng-axis__m { font-size: 9px; padding-left: 2px; }
  .eng-axis__m i { display: none; }
  .eng-seg { padding: 0 4px; font-size: 9.5px; }
  .eng-seg .l { display: none; }
  .eng-seg .s { display: inline; }
  .eng-marker i { font-size: 9px; left: 3px; }
}

/* ---------- 03 loop ---------- */
.eng-loop__grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: clamp(32px, 5vw, 88px); align-items: start; margin-top: clamp(40px, 5vw, 64px); }
.eng-ring .eng-figlabel { margin-bottom: 14px; }
@media (min-width: 1001px) { .eng-ring { position: sticky; top: calc(var(--header-h) + 72px); } }
.eng-ring__stage { position: relative; aspect-ratio: 1; max-width: 600px; margin-inline: auto; }
.eng-ring__svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.eng-ring__guide { fill: none; stroke: var(--line); stroke-width: 0.25; stroke-dasharray: 0.6 1.2; }
.eng-arc { fill: none; stroke-width: 0.75; stroke-linecap: round; }
.eng-arc--amber { stroke: var(--amber); } .eng-ah--amber { fill: var(--amber); }
.eng-arc--orange { stroke: var(--orange); } .eng-ah--orange { fill: var(--orange); }
.eng-arc--crimson { stroke: var(--crimson); } .eng-ah--crimson { fill: var(--crimson); }
.eng-arc--purple { stroke: var(--purple-ink); } .eng-ah--purple { fill: var(--purple-ink); }
.eng-spokes line { stroke: var(--line-2); stroke-width: 0.3; stroke-dasharray: 0.8 0.8; }
.eng-ring__job { fill: #fff; filter: drop-shadow(0 0 1.4px var(--amber)) drop-shadow(0 0 3px var(--amber)); opacity: 0; transition: opacity 0.3s; }
.eng-ring.is-running .eng-ring__job { opacity: 1; }
.js .eng-ring[data-reveal] .eng-arc { stroke-dasharray: 100; stroke-dashoffset: 100; opacity: 0; transition: stroke-dashoffset 1s var(--ease-out), opacity 0.2s; transition-delay: calc(0.3s + var(--i) * 0.45s); }
.js .eng-ring[data-reveal].is-in .eng-arc { stroke-dashoffset: 0; opacity: 1; }
.eng-node { position: absolute; transform: translate(-50%, -50%); z-index: 2; display: flex; align-items: baseline; gap: 8px; padding: 9px 14px 8px; border-radius: 999px; background: var(--bg-deep); border: 1.5px solid var(--c); font: 500 13px/1 var(--font-mono); white-space: nowrap; box-shadow: 0 0 0 6px var(--bg-deep); }
.eng-node__n { color: var(--c); font-size: 11px; }
.eng-node--amber { --c: var(--amber); } .eng-node--orange { --c: var(--orange); } .eng-node--crimson { --c: var(--crimson-ink); } .eng-node--purple { --c: var(--purple-ink); }
.eng-node--1 { left: 17%; top: 50%; } .eng-node--2 { left: 50%; top: 17%; } .eng-node--3 { left: 83%; top: 50%; } .eng-node--4 { left: 50%; top: 83%; }
.eng-ring__core { position: absolute; left: 50%; top: 50%; width: 36%; aspect-ratio: 1; transform: translate(-50%, -50%); border-radius: 50%; display: grid; place-content: center; text-align: center; gap: 6px; padding: 8%; background: radial-gradient(circle at 50% 40%, rgba(255, 178, 0, 0.12), rgba(18, 18, 18, 0.9) 70%); border: 1px solid var(--line-2); }
.eng-ring__core-k { font: 500 10px/1 var(--font-mono); color: var(--amber); letter-spacing: 0.04em; }
.eng-ring__core-v { font: 400 clamp(16px, 1.7vw, 22px)/1.05 var(--font-display); letter-spacing: -0.03em; }
.eng-ring__core-n { font: 400 10.5px/1.35 var(--font-mono); color: var(--ink-3); }
.eng-ring.is-pulse .eng-ring__core { animation: eng-core 1.2s var(--ease-out); }
@keyframes eng-core { 0% { box-shadow: 0 0 0 0 rgba(255, 178, 0, 0.5); } 100% { box-shadow: 0 0 0 28px rgba(255, 178, 0, 0); } }

.eng-personas { display: grid; gap: 0; }
.eng-persona { --c: var(--ink-3); display: grid; grid-template-columns: 64px minmax(0, 1fr); column-gap: 16px; row-gap: 4px; padding: 15px 0; border-top: 1px solid var(--line); position: relative; }
.eng-persona::before { content: ""; position: absolute; left: 0; top: -1px; width: 64px; height: 3px; background: var(--c); }
.eng-persona--amber { --c: var(--amber); } .eng-persona--orange { --c: var(--orange); } .eng-persona--crimson { --c: var(--crimson); } .eng-persona--purple { --c: var(--purple-ink); }
.eng-persona--human { --c: var(--ink-2); }
.eng-persona--human::before { background: repeating-linear-gradient(90deg, var(--ink-2) 0 4px, transparent 4px 8px); }
.eng-persona__n { grid-row: span 2; font: 500 11px/1.4 var(--font-mono); color: var(--c); padding-top: 4px; }
.eng-persona--purple .eng-persona__n { color: var(--purple-ink); }
.eng-persona__name { font: 400 clamp(20px, 1.8vw, 26px)/1.1 var(--font-display); letter-spacing: -0.03em; }
.eng-persona__body { font: 400 15px/1.55 var(--font-text); color: var(--ink-2); }

.eng-chain { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 0; margin-top: clamp(40px, 5vw, 64px); border: 1px solid var(--line); border-radius: var(--radius-lg); overflow: hidden; }
.eng-chain__step { position: relative; display: grid; align-content: start; gap: 8px; padding: 22px 26px 24px 20px; background: var(--bg); }
.eng-chain__step + .eng-chain__step { border-left: 1px solid var(--line); }
.eng-chain__step:not(:last-child)::after { content: "→"; position: absolute; right: -9px; top: 22px; z-index: 2; font: 400 16px/1 var(--font-display); color: var(--amber); background: var(--bg); padding: 2px 0; }
.eng-chain__step--hot { background: color-mix(in srgb, var(--amber) 9%, var(--bg)); }
.eng-chain__k { font: 500 11px/1 var(--font-mono); color: var(--amber); letter-spacing: 0.03em; }
.eng-chain__v { font: 400 clamp(20px, 1.7vw, 26px)/1.05 var(--font-display); letter-spacing: -0.03em; }
.eng-chain__n { font: 400 12.5px/1.5 var(--font-mono); color: var(--ink-3); }
@media (max-width: 1000px) {
  .eng-loop__grid { grid-template-columns: 1fr; }
  .eng-ring__stage { max-width: 520px; }
  .eng-chain { grid-template-columns: 1fr; }
  .eng-chain__step + .eng-chain__step { border-left: 0; border-top: 1px solid var(--line); }
  .eng-chain__step:not(:last-child)::after { content: "↓"; right: auto; left: 20px; top: auto; bottom: -10px; padding: 0 4px; }
  .eng-chain__step { grid-template-columns: 110px minmax(0, 1fr); column-gap: 14px; }
  .eng-chain__k { grid-row: span 2; padding-top: 6px; }
}
@media (max-width: 480px) {
  .eng-node { font-size: 11.5px; padding: 7px 10px 6px; gap: 6px; box-shadow: 0 0 0 4px var(--bg-deep); }
  .eng-node__n { font-size: 10px; }
  .eng-ring__core { width: 40%; padding: 6%; gap: 4px; }
  .eng-ring__core-n { display: none; }
  .eng-persona { grid-template-columns: 1fr; }
  .eng-persona__n { grid-row: auto; padding-top: 6px; }
  .eng-chain__step { grid-template-columns: 1fr; }
  .eng-chain__k { grid-row: auto; padding-top: 0; }
}

/* ---------- deeper panels (<details>) ---------- */
.eng-deep { margin-top: clamp(40px, 5vw, 72px); border-bottom: 1px solid var(--line); }
.eng-panel { border-top: 1px solid var(--line); }
.eng-panel__sum { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: baseline; gap: 4px 18px; padding: 20px 0; cursor: pointer; list-style: none; }
.eng-panel__sum::-webkit-details-marker { display: none; }
.eng-panel__lvl { display: inline-flex; align-items: center; font: 500 12px/1 var(--font-mono); color: var(--crimson-ink); white-space: nowrap; }
.eng-panel__lvl--src, .eng-toc__lvl { color: var(--purple-ink); }
.eng-toc__lvl { display: inline-flex; align-items: center; }
.eng-panel__title { font: 400 clamp(19px, 1.8vw, 26px)/1.15 var(--font-display); letter-spacing: -0.025em; }
.eng-panel__icon { position: relative; width: 16px; height: 16px; align-self: center; }
.eng-panel__icon::before, .eng-panel__icon::after { content: ""; position: absolute; left: 0; top: 7px; width: 16px; height: 2px; background: var(--crimson-ink); transition: transform 0.3s var(--ease); }
.eng-panel__icon::after { transform: rotate(90deg); }
.eng-panel[open] > .eng-panel__sum .eng-panel__icon::after { transform: rotate(0deg); }
.eng-panel__sum:hover .eng-panel__title { color: var(--amber-ink); }
.eng-panel__body { padding: 4px 0 36px; }
.eng-panel__body > .chips { margin-top: 24px; }
.eng-prose-doc { max-width: 84ch; font-size: 16px; }
.eng-prose-doc h3 { font-size: clamp(22px, 2vw, 30px); }
@media (max-width: 600px) {
  .eng-panel__sum { grid-template-columns: minmax(0, 1fr) auto; }
  .eng-panel__lvl { grid-column: 1 / -1; }
}

.eng-life { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 3px; counter-reset: none; }
.eng-life__step { background: var(--bg-raise); padding: 18px 20px 20px; display: grid; align-content: start; gap: 8px; border-top: 2px solid var(--amber); position: relative; }
.eng-life__step--fail { border-top: 2px dashed var(--crimson-ink); background: color-mix(in srgb, var(--crimson) 10%, var(--bg-raise)); grid-column: 1 / -1; }
.eng-life__n { font: 500 11px/1 var(--font-mono); color: var(--amber); }
.eng-life__step--fail .eng-life__n { color: var(--crimson-ink); }
.eng-life__name { font: 400 22px/1.1 var(--font-display); letter-spacing: -0.03em; }
.eng-life__body { font: 400 13px/1.6 var(--font-mono); color: var(--ink-2); }
.eng-life__body::first-letter { text-transform: uppercase; }
.eng-life__note { margin-top: 18px; color: var(--ink-3); font-size: 12.5px; max-width: 90ch; }
@media (max-width: 860px) { .eng-life { grid-template-columns: 1fr; } }

.eng-stack { display: grid; gap: 0; margin: 0; }
.eng-stack__row { display: grid; grid-template-columns: 160px minmax(0, 1fr); gap: 14px; padding: 12px 0; border-top: 1px solid var(--line); }
.eng-stack--wide .eng-stack__row { grid-template-columns: 220px minmax(0, 1fr); }
.eng-stack dt { font: 500 12px/1.45 var(--font-mono); color: var(--ink-3); text-transform: uppercase; letter-spacing: 0.02em; }
.eng-stack dd { margin: 0; display: grid; gap: 4px; font: 400 13.5px/1.55 var(--font-mono); color: var(--ink-2); }
.eng-stack dd b { font: 400 16px/1.35 var(--font-text); color: var(--ink); }
.eng-stack dd em { font-style: normal; color: var(--ink-3); font-size: 12px; }
@media (max-width: 600px) { .eng-stack__row, .eng-stack--wide .eng-stack__row { grid-template-columns: 1fr; gap: 6px; } }

/* ---------- 04 fleet (signature) ---------- */
.eng-fleet-band { position: relative; overflow: hidden; }
.eng-fleet-band::before { content: ""; position: absolute; inset: 20% -10% auto 30%; height: 70%; background: radial-gradient(50% 50% at 40% 50%, rgba(100, 13, 95, 0.28), transparent 70%); pointer-events: none; z-index: -1; }
.eng-fleet { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(0, 1fr); grid-template-areas: "field readout" "tl tl"; column-gap: clamp(32px, 4.5vw, 80px); row-gap: clamp(40px, 5vw, 72px); align-items: start; margin-top: clamp(40px, 5vw, 72px); }
.eng-field-fig { grid-area: field; }
.eng-readout { grid-area: readout; }
.eng-fleet > .eng-tl { grid-area: tl; margin-top: 0; }
.eng-field-fig { min-width: 0; }
.eng-hud { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 11.5px; color: var(--ink-3); margin-bottom: 14px; }
.eng-hud b { color: var(--ink); font-weight: 500; }
.eng-hud__replan { color: var(--ink-3); transition: color 0.2s; }
.eng-hud__replan.is-on { color: var(--amber); }
.eng-field { position: relative; display: grid; gap: clamp(4px, 0.5vw, 7px); padding: clamp(12px, 1.6vw, 22px); background: var(--bg-deep); border: 1px solid var(--line); border-radius: var(--radius-lg); }
.eng-field__row { display: grid; grid-template-columns: 48px minmax(0, 1fr); align-items: center; gap: 8px; }
.eng-field__label { display: flex; align-items: center; gap: 6px; font: 400 10px/1 var(--font-mono); color: var(--ink-2); transition: color 0.4s; }
.eng-field__led { width: 5px; height: 5px; border-radius: 50%; background: var(--amber); box-shadow: 0 0 6px var(--amber); flex: none; transition: background 0.4s, box-shadow 0.4s; }
.eng-field__row.is-off .eng-field__led { background: #3a3a3a; box-shadow: none; }
.eng-field__row.is-head .eng-field__label { color: var(--amber); }
.eng-field__cells { display: grid; grid-template-columns: repeat(16, minmax(0, 1fr)); gap: clamp(4px, 0.5vw, 7px); }
.eng-field .c { display: block; aspect-ratio: 1; border-radius: 3px; background-color: var(--pc); background-image: radial-gradient(circle at 32% 28%, rgba(255, 255, 255, 0.28), rgba(255, 255, 255, 0) 42%); box-shadow: 0 0 10px -3px var(--pc); transition: background-color 0.5s var(--ease), box-shadow 0.5s, opacity 0.5s; transition-delay: var(--d, 0s); }
.eng-field .p0 { --pc: var(--amber); } .eng-field .p1 { --pc: var(--orange); } .eng-field .p2 { --pc: var(--crimson); } .eng-field .p3 { --pc: var(--purple-ink); }
.eng-field .c.f { background-color: #fff; box-shadow: 0 0 14px 2px var(--pc), 0 0 3px 1px #fff; transition-duration: 0.06s; transition-delay: 0s; }
.eng-field__row.is-off .c { background-color: transparent; background-image: radial-gradient(circle, rgba(255, 255, 255, 0.16) 0 18%, rgba(255, 255, 255, 0) 21%); box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.05); }
.eng-field__row.is-off .eng-field__label { color: #555; }
.eng-field__scan { position: absolute; left: 0; right: 0; top: 0; height: 2px; background: linear-gradient(90deg, transparent, var(--amber) 15%, #fff 50%, var(--amber) 85%, transparent); box-shadow: 0 0 18px 3px rgba(255, 178, 0, 0.45); opacity: 0; pointer-events: none; border-radius: 2px; }
.eng-field.is-scan .eng-field__scan { animation: eng-scan 0.9s var(--ease) 1; }
@keyframes eng-scan { 0% { top: 0; opacity: 0; } 12% { opacity: 1; } 88% { opacity: 1; } 100% { top: calc(100% - 2px); opacity: 0; } }
.eng-legend { display: flex; flex-wrap: wrap; gap: 8px 18px; list-style: none; padding: 0; margin: 16px 0 0; font: 400 12px/1.2 var(--font-mono); color: var(--ink-2); }
.eng-legend li { display: flex; align-items: center; gap: 7px; }
.eng-legend__sw { width: 12px; height: 12px; border-radius: 2px; }
.eng-legend__sw--amber { background: var(--amber); } .eng-legend__sw--orange { background: var(--orange); } .eng-legend__sw--crimson { background: var(--crimson); } .eng-legend__sw--purple { background: var(--purple-ink); }
.eng-legend__sw--off { box-shadow: inset 0 0 0 1px var(--line-2); }

.eng-readout { min-width: 0; }
.eng-ctrl { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px; margin-bottom: 26px; }
.eng-ctrl__play { display: inline-flex; align-items: center; gap: 10px; padding: 12px 18px 12px 14px; border: 1px solid var(--amber); border-radius: 3px; font: 500 13px/1 var(--font-mono); color: var(--amber); transition: background 0.2s, color 0.2s; }
.eng-ctrl__play:hover { background: var(--amber); color: #121212; }
.eng-ctrl__icon { width: 0; height: 0; border-style: solid; border-width: 6px 0 6px 10px; border-color: transparent transparent transparent currentColor; }
.eng-ctrl__play[aria-pressed="true"] .eng-ctrl__icon { width: 10px; height: 12px; border: 0; border-left: 3px solid currentColor; border-right: 3px solid currentColor; }
.eng-ctrl__hint { color: var(--ink-3); font-size: 12px; }
.no-js .eng-ctrl { display: none; }
.js .eng-month:not(.is-active) { display: none; }
.no-js .eng-month + .eng-month { margin-top: 48px; padding-top: 32px; border-top: 1px solid var(--line); }
.eng-month__k { color: var(--amber); font-size: 12.5px; font-weight: 500; }
.eng-month__fleet { color: var(--ink-2); font-size: 12.5px; margin-top: 8px; }
.eng-month__fleet b { color: var(--ink); font-weight: 500; }
.eng-month__focus { font: 400 clamp(24px, 2.3vw, 34px)/1.08 var(--font-display); letter-spacing: -0.03em; margin-top: 18px; text-wrap: pretty; }
.eng-month__jobs { margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--line); }
.eng-month__total { display: flex; align-items: baseline; gap: 10px; color: var(--ink-2); }
.eng-month__num { font: 400 clamp(44px, 4.4vw, 68px)/0.9 var(--font-display); letter-spacing: -0.05em; color: var(--ink); }
.eng-mix { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 6px; }
.eng-mix li { display: grid; grid-template-columns: 44px minmax(0, 1fr) 64px; align-items: center; gap: 12px; font: 400 12.5px/1 var(--font-mono); }
.eng-mix__k { color: var(--ink); text-decoration: none; border-bottom: 1px dotted var(--ink-3); justify-self: start; }
.eng-mix__k:hover { color: var(--amber); border-bottom-color: var(--amber); }
.eng-mix__bar { height: 6px; background: rgba(255, 255, 255, 0.06); border-radius: 0 3px 3px 0; overflow: hidden; }
.eng-mix__bar i { display: block; height: 100%; width: max(2px, var(--w)); background: var(--orange); border-radius: 0 3px 3px 0; }
.eng-mix__n { text-align: right; color: var(--ink-2); }
.eng-month__narrow { margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--line); }
.eng-month__lbl { color: var(--orange-ink); font-size: 11.5px; margin-bottom: 12px; }
.eng-month__narrow .eng-bullets { font: 400 16px/1.45 var(--font-text); color: var(--ink); }
.eng-month__narrow .eng-bullets li::first-letter { text-transform: uppercase; }
.eng-month__plan { display: inline-flex; gap: 8px; margin-top: 24px; font: 400 13px/1 var(--font-mono); color: var(--ink-2); text-decoration: none; border-bottom: 1px solid var(--line-2); padding-bottom: 6px; }
.eng-month__plan:hover { color: var(--amber); border-bottom-color: var(--amber); }
@media (max-width: 1000px) { .eng-fleet { grid-template-columns: 1fr; grid-template-areas: "field" "tl" "readout"; row-gap: 40px; } .eng-ctrl { margin-bottom: 20px; } }
@media (max-width: 480px) {
  .eng-field__row { grid-template-columns: 36px minmax(0, 1fr); gap: 4px; }
  .eng-field__label { font-size: 8.5px; gap: 4px; }
  .eng-field__led { width: 4px; height: 4px; }
  .eng-field__cells, .eng-field { gap: 2.5px; }
  .eng-field { padding: 8px; }
}

/* 12-month chart / scrubber */
.eng-tl { margin-top: clamp(48px, 6vw, 80px); }
.eng-tl__legend { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 20px; font-size: 12px; color: var(--ink-2); margin-bottom: 18px; }
.eng-tl__key { display: inline-flex; align-items: center; gap: 7px; }
.eng-tl__sw { width: 12px; height: 12px; border-radius: 2px; display: inline-block; }
.eng-tl__sw--fleet { background: var(--amber); } .eng-tl__sw--heavy { background: var(--orange); } .eng-tl__sw--k0 { background: var(--purple-ink); }
.eng-tl__note { color: var(--ink-3); margin-left: auto; }
.eng-tl__chart { display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 10px; }
.eng-tl__axis { display: grid; grid-template-rows: 70px 150px auto; font-size: 10.5px; line-height: 1.25; color: var(--ink-3); text-align: right; }
.eng-tl__ax { padding-top: 0; }
.eng-tl__ax--jobs { padding-top: 14px; }
.eng-tl__cols { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: clamp(3px, 0.6vw, 8px); }
.eng-tl__col { display: grid; grid-template-rows: 70px 150px auto; padding: 0; text-align: left; border-radius: 4px; position: relative; color: var(--ink-2); transition: background 0.2s; }
.eng-tl__col:hover { background: rgba(255, 255, 255, 0.04); }
.eng-tl__col::after { content: ""; position: absolute; left: 0; right: 0; bottom: -10px; height: 3px; background: transparent; border-radius: 2px; transition: background 0.2s; }
.eng-tl__col.is-active::after { background: var(--amber); }
.eng-tl__col.is-active { color: var(--ink); background: rgba(255, 255, 255, 0.06); }
.eng-tl__fleet { position: relative; display: flex; align-items: flex-end; border-bottom: 1px solid var(--line-2); }
.eng-tl__fleet i { position: relative; display: block; width: 100%; height: calc(var(--h) * 100%); background: var(--amber); border-radius: 3px 3px 0 0; }
.eng-tl__fleet b { position: absolute; left: 5px; top: 4px; font: 700 10.5px/1 var(--font-mono); color: #121212; }
.eng-tl__jobs { position: relative; display: flex; flex-direction: column-reverse; justify-content: flex-start; padding-top: 20px; border-bottom: 1px solid var(--line-2); }
.eng-tl__jobs i { display: block; width: 100%; flex: none; height: calc(var(--h) * (100% - 0px)); min-height: 2px; }
.eng-tl__jobs { --H: 128px; }
.eng-tl__jobs i { height: max(2px, calc(var(--h) * var(--H))); }
.eng-tl__k0 { background: var(--purple-ink); border-radius: 3px 3px 0 0; margin-top: 2px; }
.eng-tl__heavy { background: var(--orange); }

.eng-tl__k0[style*="--h: 0;"] { display: none; }
.eng-tl__val { position: relative; font: 400 10.5px/1 var(--font-mono); font-style: normal; color: var(--ink-2); padding: 0 0 5px 2px; }
.eng-tl__m { display: grid; gap: 3px; padding: 8px 2px 0; font: 400 10.5px/1 var(--font-mono); color: var(--ink-3); }
.eng-tl__m b { font-weight: 500; color: inherit; }
.eng-tl__col.is-active .eng-tl__m b { color: var(--amber); }
@media (max-width: 640px) {
  .eng-tl__chart { grid-template-columns: minmax(0, 1fr); }
  .eng-tl__axis { display: none; }
  .eng-tl__col, .eng-tl__axis { grid-template-rows: 48px 120px auto; }
  .eng-tl__jobs { --H: 98px; }
  .eng-tl__val { font-size: 8.5px; padding-left: 0; writing-mode: initial; }
  .eng-tl__m { font-size: 9px; }
  .eng-tl__m span { display: none; }
  .eng-tl__fleet b { font-size: 9px; left: 2px; }
  .eng-tl__note { margin-left: 0; }
}

/* ---------- 05 decision link (paper) ---------- */
.eng-dl .display-2 { color: var(--paper-ink); }
.eng-dl__accent { color: var(--purple); }
.eng-dl__lead { color: var(--paper-ink-2); margin-top: clamp(24px, 3vw, 40px); }
.eng-dl__map { margin-top: clamp(40px, 5vw, 72px); --dl-cols: minmax(0, 1fr) minmax(0, 1.45fr) minmax(220px, 1fr) 140px; }
.eng-dl__head { display: grid; grid-template-columns: var(--dl-cols); gap: 24px; padding-bottom: 12px; font: 500 11px/1.2 var(--font-mono); color: var(--purple); letter-spacing: 0.03em; border-bottom: 1px solid var(--paper-ink); }
.eng-dl__months-h { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 2px; }
.eng-dl__months-h i { font-style: normal; text-align: center; color: var(--paper-ink-2); }
.eng-dl__rows { list-style: none; margin: 0; padding: 0; }
.eng-dl__row { display: grid; grid-template-columns: var(--dl-cols); gap: 24px; align-items: start; padding: 15px 0; border-bottom: 1px solid var(--paper-line); transition: background 0.2s; }
.eng-dl__row:hover { background: rgba(100, 13, 95, 0.04); }
.eng-dl__sim { display: grid; gap: 8px; justify-items: start; }
.eng-dl__name { font: 400 clamp(19px, 1.6vw, 23px)/1.15 var(--font-display); letter-spacing: -0.025em; color: var(--paper-ink); }
.eng-dl__cls { display: flex; flex-wrap: wrap; gap: 4px; }
.eng-dl__cls a, .eng-fam__cls a { font: 500 11px/1 var(--font-mono); text-decoration: none; padding: 4px 6px 3px; border-radius: 3px; border: 1px solid currentColor; }
.eng-dl__cls a { color: var(--purple); }
.eng-dl__cls a:hover { background: var(--purple); color: #fff; }
.eng-dl__param { display: grid; grid-template-columns: 20px minmax(0, 1fr); gap: 8px; font: 400 15px/1.5 var(--font-text); color: var(--paper-ink-2); }
.eng-dl__arrow { color: var(--purple); font: 400 18px/1.2 var(--font-display); }
.eng-dl__months { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 2px; padding-top: 4px; }
.eng-dl__months i { height: 18px; background: rgba(0, 0, 0, 0.07); border-radius: 2px; }
.eng-dl__months i.is-on { background: var(--purple); }
.eng-dl__months i.is-onward { background: linear-gradient(90deg, var(--purple) 60%, var(--crimson)); }
.eng-dl__when { grid-column: 1 / -1; margin-top: 8px; font-size: 11.5px; color: var(--paper-ink-2); }
.eng-dl__owner { font-size: 13px; font-weight: 500; color: var(--paper-ink); padding-top: 3px; }
.eng-dl__foot { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 16px 32px; margin-top: 28px; }
.eng-dl__note { font-size: 12px; color: var(--paper-ink-2); max-width: 70ch; }
@media (max-width: 1000px) {
  .eng-dl__head { display: none; }
  .eng-dl__row { grid-template-columns: minmax(0, 1fr) auto; grid-template-areas: "sim sim" "param param" "months months"; gap: 10px 12px; padding: 18px 0; }
  .eng-dl__sim { grid-area: sim; grid-template-columns: minmax(0, 1fr) auto; align-items: baseline; }
  .eng-dl__param { grid-area: param; font-size: 14.5px; }
  .eng-dl__months { grid-area: months; }
  .eng-dl__owner { grid-area: months; align-self: end; justify-self: end; font-size: 12px; padding-top: 0; }
  .eng-dl__owner::before { content: "Owner: "; font-weight: 400; color: var(--paper-ink-2); }
  .eng-dl__months i { height: 14px; }
}

/* ---------- 06 toolchain ---------- */
.eng-qs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 3px; margin-top: clamp(40px, 5vw, 64px); }
.eng-q { background: var(--bg-raise); padding: 22px 24px 24px; display: grid; align-content: start; gap: 10px; border-radius: 3px; }
.eng-q__n { font: 400 clamp(40px, 4vw, 64px)/0.9 var(--font-display); letter-spacing: -0.05em; color: var(--amber); }
.eng-q__text { font: 400 clamp(19px, 1.6vw, 24px)/1.2 var(--font-display); letter-spacing: -0.02em; }
.eng-q__meta { font-size: 12.5px; color: var(--ink-3); line-height: 1.5; }
.eng-q__meta span { color: var(--ink-2); }
@media (max-width: 900px) { .eng-qs { grid-template-columns: 1fr; } }

.eng-fam { margin: clamp(40px, 5vw, 64px) 0 0; border-bottom: 1px solid var(--line); }
.eng-fam__item { border-top: 1px solid var(--line); }
.eng-fam__sum { display: grid; grid-template-columns: 150px minmax(200px, 0.8fr) minmax(0, 1.5fr) 150px 18px; gap: 6px clamp(16px, 2.4vw, 36px); align-items: baseline; padding: 20px 0; cursor: pointer; list-style: none; }
.eng-fam__sum::-webkit-details-marker { display: none; }
.eng-fam__sum:hover .eng-fam__name { color: var(--amber-ink); }
.eng-fam__scale { display: grid; gap: 4px; font-size: 11px; color: var(--ink-3); }
.eng-fam__scale span:first-child { color: var(--amber); }
.eng-fam__scale span:nth-child(2) { color: var(--ink); font-weight: 500; }
.eng-fam__name { font: 400 clamp(22px, 2vw, 30px)/1.05 var(--font-display); letter-spacing: -0.035em; transition: color 0.2s; }
.eng-fam__plain { font: 400 15.5px/1.5 var(--font-text); color: var(--ink-2); }
.eng-fam__cls { display: flex; flex-wrap: wrap; gap: 4px; justify-content: flex-end; }
.eng-fam__cls span { font-size: 11px; padding: 3px 6px 2px; border: 1px solid var(--line-2); border-radius: 3px; color: var(--ink-2); }
.eng-fam__sum .eng-k__chev { align-self: center; }
.eng-fam__item[open] .eng-k__chev { transform: rotate(225deg) translateY(-2px); border-color: var(--amber); }
.eng-fam__more { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); gap: 16px clamp(20px, 3vw, 48px); padding: 0 0 26px calc(150px + clamp(16px, 2.4vw, 36px)); }
.eng-fam__codes { grid-column: 1 / -1; font-size: 13px; color: var(--amber-ink); }
.eng-fam__codes span { color: var(--ink-3); margin-right: 10px; }
.eng-fam__dl { display: contents; }
.eng-fam__dl > div { margin: 0; }
.eng-fam__dl dt { font-size: 11px; color: var(--orange-ink); margin-bottom: 6px; }
.eng-fam__dl dd { margin: 0; font: 400 14px/1.6 var(--font-mono); color: var(--ink-2); }
.eng-fam__dl div + div dt { color: var(--ink-3); }
.eng-fam__foot { grid-column: 1 / -1; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 20px; font-size: 12.5px; color: var(--ink-3); }
.eng-fam__links a { color: var(--ink-2); margin-left: 8px; text-decoration: none; border-bottom: 1px dotted var(--ink-3); }
.eng-fam__links a:hover { color: var(--amber); }
.eng-fam__src { color: var(--ink-2); text-decoration: none; }
.eng-fam__src:hover { color: var(--amber); }
@media (max-width: 1000px) {
  .eng-fam__sum { grid-template-columns: minmax(0, 1fr) 18px; grid-template-areas: "scale chev" "name name" "plain plain" "cls cls"; }
  .eng-fam__scale { grid-area: scale; display: flex; flex-wrap: wrap; gap: 4px 12px; }
  .eng-fam__name { grid-area: name; }
  .eng-fam__plain { grid-area: plain; }
  .eng-fam__cls { grid-area: cls; justify-content: flex-start; }
  .eng-fam__sum .eng-k__chev { grid-area: chev; align-self: start; }
  .eng-fam__more { grid-template-columns: 1fr; padding-left: 0; }
}

.eng-ladder { display: grid; grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr); gap: clamp(24px, 4vw, 64px); align-items: end; }

.eng-ladder__h { margin-bottom: 20px; }
.eng-ladder__p { font: 400 16px/1.6 var(--font-text); color: var(--ink-2); max-width: 52ch; margin-bottom: 20px; }
.eng-rungs { display: flex; flex-direction: column-reverse; gap: 4px; }
.eng-rung { margin-left: calc(var(--i) * 6%); display: grid; grid-template-columns: 96px minmax(0, 1fr); column-gap: 16px; row-gap: 4px; padding: 16px 18px; background: var(--bg-raise); border-left: 3px solid var(--amber); border-radius: 0 3px 3px 0; }
.eng-rung:nth-child(2) { border-left-color: var(--orange); }
.eng-rung:nth-child(3) { border-left-color: var(--crimson); }
.eng-rung:nth-child(4) { border-left-color: var(--purple-ink); }
.eng-rung:nth-child(5) { border-left-color: var(--ink-2); }
.eng-rung__n { grid-row: span 2; font-size: 11px; color: var(--ink-3); padding-top: 4px; }
.eng-rung__name { font: 400 20px/1.15 var(--font-display); letter-spacing: -0.025em; }
.eng-rung__body { font: 400 12.5px/1.55 var(--font-mono); color: var(--ink-2); }
@media (max-width: 1000px) { .eng-ladder { grid-template-columns: 1fr; } }
@media (max-width: 560px) { .eng-rung { grid-template-columns: 1fr; margin-left: calc(var(--i) * 3%); } .eng-rung__n { grid-row: auto; padding-top: 0; } }

/* ---------- 07 job classes ---------- */
.eng-k-panel { margin-top: clamp(32px, 4vw, 56px); border-bottom: 1px solid var(--line); }
.eng-k-panel > .eng-k { margin: 4px 0 28px; }
.eng-deep--flush { margin-top: 0; }
.eng-deep--flush .eng-panel:first-child { border-top: 0; }
.eng-k { --kcols: 52px minmax(0, 2.1fr) 56px 96px 64px minmax(150px, 1.3fr) 80px 92px 18px; }
.eng-k__head { display: grid; grid-template-columns: var(--kcols); gap: 14px; padding: 0 0 12px; font-size: 11px; text-transform: uppercase; letter-spacing: 0.03em; color: var(--amber); border-bottom: 1px solid var(--line-2); }
.eng-k__head .r, .eng-k .r { text-align: right; }
.eng-k__log { font-style: normal; color: var(--ink-3); text-transform: none; margin-left: 4px; }
.eng-k__row { border-bottom: 1px solid var(--line); scroll-margin-top: calc(var(--header-h) + 70px); }
.eng-k__row:target, .eng-k__row.is-flash { background: rgba(255, 178, 0, 0.06); }
.eng-k__sum { display: grid; grid-template-columns: var(--kcols); gap: 14px; align-items: center; padding: 14px 0; cursor: pointer; list-style: none; }
.eng-k__sum::-webkit-details-marker { display: none; }
.eng-k__sum:hover { background: rgba(255, 255, 255, 0.025); }
.eng-k__cls { font: 400 26px/1 var(--font-display); letter-spacing: -0.04em; color: var(--amber); }
.eng-k__tool { display: grid; gap: 3px; min-width: 0; }
.eng-k__tool b { font: 400 16px/1.25 var(--font-text); color: var(--ink); }
.eng-k__tool span { font: 400 12.5px/1.45 var(--font-mono); color: var(--ink-3); }
.eng-k__num { font: 400 13px/1.3 var(--font-mono); color: var(--ink-2); white-space: nowrap; }
.eng-k__cost { display: grid; grid-template-columns: minmax(0, 1fr) 52px; align-items: center; gap: 10px; }
.eng-k__cost b { font: 500 13px/1 var(--font-mono); color: var(--ink); text-align: right; }
.eng-k__bar { position: relative; height: 8px; background: repeating-linear-gradient(90deg, rgba(255, 255, 255, 0.08) 0 1px, transparent 1px calc(100% / 6)); border-radius: 1px; }
.eng-k__bar i { position: absolute; left: 0; top: 0; bottom: 0; width: var(--w, 0%); background: linear-gradient(90deg, var(--purple-ink), var(--crimson) 55%, var(--orange) 80%, var(--amber)); background-size: var(--bs, 100%) 100%; border-radius: 0 2px 2px 0; transition: width 1s var(--ease-out); }
.no-js .eng-k__bar { display: none; }
.eng-k__chev { width: 9px; height: 9px; border-right: 1.5px solid var(--ink-3); border-bottom: 1.5px solid var(--ink-3); transform: rotate(45deg) translateY(-3px); transition: transform 0.25s var(--ease); justify-self: end; }
.eng-k__row[open] .eng-k__chev { transform: rotate(225deg) translateY(-2px); border-color: var(--amber); }
.eng-k__more { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); gap: 32px; padding: 6px 0 26px 66px; }
.eng-k__lbl { font-size: 11px; color: var(--orange-ink); margin-bottom: 12px; }
.eng-k__runs { display: flex; flex-wrap: wrap; gap: 4px; list-style: none; padding: 0; margin: 0 0 10px; }
.eng-k__runs li { display: grid; gap: 4px; padding: 8px 10px; background: var(--bg-raise); border-radius: 3px; min-width: 64px; }
.eng-k__runs .mono { font-size: 11px; color: var(--ink-3); }
.eng-k__runs b { font: 400 18px/1 var(--font-display); letter-spacing: -0.02em; }
.eng-k__small { font-size: 12.5px; color: var(--ink-3); line-height: 1.55; }
.eng-k__more .eng-bullets { font: 400 14px/1.55 var(--font-text); color: var(--ink-2); }
.eng-k__more .eng-bullets b { color: var(--ink); font-weight: 400; }
.eng-k__foot { margin-top: 18px; font-size: 12px; color: var(--ink-3); max-width: 100ch; }
@media (max-width: 1100px) {
  .eng-k__head { display: none; }
  .eng-k__cls { grid-area: cls; align-self: start; }
  .eng-k__tool { grid-area: tool; }
  .eng-k__chev { grid-area: chev; align-self: start; margin-top: 6px; }
  .eng-k__more { grid-template-columns: 1fr; padding-left: 0; }
}

/* ---------- 08 cost ---------- */
.eng-cost__grid { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr); gap: clamp(32px, 5vw, 80px); margin-top: clamp(40px, 5vw, 64px); align-items: start; }
.eng-cost__grid .eng-scales { grid-template-columns: 1fr; gap: 16px; margin-top: 0; }
.eng-cost__grid .eng-scales__intro p { margin: 10px 0 14px; }
.eng-figs { list-style: none; padding: 0; margin: 0; display: grid; }
.eng-figs__item { display: grid; gap: 8px; padding: 20px 0 22px; border-top: 1px solid var(--line-2); }
.eng-figs__k { font-size: 11.5px; color: var(--amber); }
.eng-figs__v { font: 400 clamp(48px, 5.4vw, 88px)/0.9 var(--font-display); letter-spacing: -0.055em; }
.eng-figs__n { font: 400 13px/1.6 var(--font-mono); color: var(--ink-2); max-width: 54ch; }
.eng-figs__item--sum .eng-figs__v { color: var(--amber); }
.eng-mbars { background: var(--bg-deep); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: clamp(18px, 2.4vw, 30px); }
.eng-mbars__plot { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: clamp(3px, 0.7vw, 9px); align-items: end; height: 260px; margin-top: 20px; border-bottom: 1px solid var(--line-2); }
.eng-mbars__col { display: flex; flex-direction: column; justify-content: flex-end; height: 100%; position: relative; }
.eng-mbars__stack { display: flex; flex-direction: column; justify-content: flex-end; height: 200px; }
.eng-mbars__stack i { display: block; height: calc(var(--h) * 200px); }
.eng-mbars__tok { background: var(--purple-ink); border-radius: 3px 3px 0 0; margin-bottom: 2px; }
.eng-mbars__cmp { background: var(--orange); }
.eng-mbars__val { order: -1; font-size: 10px; color: var(--ink-2); padding-bottom: 6px; text-align: center; }
.eng-mbars__m { position: absolute; bottom: -22px; left: 0; right: 0; text-align: center; font-size: 10px; color: var(--ink-3); }
.eng-mbars__col { height: auto; }
.eng-mbars__legend { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 38px; font-size: 12px; color: var(--ink-2); }
.eng-mbars__legend span { display: inline-flex; align-items: center; gap: 7px; }
.eng-sw { width: 12px; height: 12px; border-radius: 2px; display: inline-block; }
.eng-sw--cmp { background: var(--orange); } .eng-sw--tok { background: var(--purple-ink); }
.js .eng-mbars[data-reveal] .eng-mbars__stack { transform: scaleY(0); transform-origin: bottom; transition: transform 1s var(--ease-out); }
.js .eng-mbars[data-reveal].is-in .eng-mbars__stack { transform: none; }
.eng-mbars__col:nth-child(n) .eng-mbars__stack { transition-delay: calc(var(--d, 0) * 1s); }

.eng-scales { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: clamp(32px, 5vw, 88px); margin-top: clamp(64px, 8vw, 120px); align-items: start; }
.eng-scales__intro p { font: 400 16px/1.6 var(--font-text); color: var(--ink-2); margin: 16px 0 20px; max-width: 54ch; }
.eng-sbars { list-style: none; padding: 0; margin: 0; display: grid; gap: 4px; }
.eng-sbar { display: grid; grid-template-columns: minmax(0, 1fr) auto; grid-template-areas: "name v" "bar bar" "n n"; gap: 8px 16px; padding: 16px 0 18px; border-top: 1px solid var(--line); }
.eng-sbar::before { content: ""; grid-area: bar; height: 10px; background: rgba(255, 255, 255, 0.05); border-radius: 2px; }
.eng-sbar__fill { grid-area: bar; height: 10px; width: calc(var(--w) * 100%); background: var(--ink-3); border-radius: 2px; transform-origin: left; }
.eng-sbar--plan .eng-sbar__fill { background: var(--amber); box-shadow: 0 0 18px -4px var(--amber); }
.eng-sbar__name { grid-area: name; font: 400 18px/1.2 var(--font-display); letter-spacing: -0.02em; color: var(--ink-2); }
.eng-sbar__name b { font-weight: 700; color: var(--ink); }
.eng-sbar--plan .eng-sbar__name b { color: var(--amber); }
.eng-sbar__v { grid-area: v; font: 400 clamp(22px, 2vw, 30px)/1 var(--font-display); letter-spacing: -0.04em; text-align: right; }
.eng-sbar--plan .eng-sbar__v { color: var(--amber); }
.eng-sbar__n { grid-area: n; font-size: 11.5px; line-height: 1.5; color: var(--ink-3); max-width: 72ch; }
.js .eng-scales[data-reveal] .eng-sbar__fill { transform: scaleX(0); transition: transform 1.1s var(--ease-out); }
.js .eng-scales[data-reveal].is-in .eng-sbar__fill { transform: none; }
.eng-cost__excl { margin-top: 28px; font-size: 12px; color: var(--ink-3); }
@media (max-width: 1000px) { .eng-cost__grid, .eng-scales { grid-template-columns: 1fr; } }
@media (max-width: 560px) {
  .eng-mbars__plot { height: 200px; }
  .eng-mbars__stack { height: 150px; }
  .eng-mbars__stack i { height: calc(var(--h) * 150px); }
  .eng-mbars__val { font-size: 8px; }
  .eng-mbars__m { font-size: 8.5px; }
  .eng-sbar__name { font-size: 16px; }
}

/* ---------- 09 provenance ---------- */
.eng-prov__title { max-width: 14ch; }
.eng-prov__grid { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); gap: clamp(32px, 5vw, 80px); margin-top: clamp(40px, 5vw, 64px); align-items: start; }
.eng-prov__grid .eng-anchor { margin-top: 0; }
.eng-rec { max-width: 760px; }
.eng-rec { background: var(--paper); color: var(--paper-ink); border-radius: var(--radius); padding: 0 0 18px; box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45); }
.eng-rec__bar { display: flex; justify-content: space-between; padding: 14px 20px; font-size: 11.5px; color: var(--purple); border-bottom: 1px solid var(--paper-line); font-weight: 600; }
.eng-rec__dl { margin: 0; padding: 6px 20px 0; font-size: 13px; }
.eng-rec__dl div { display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 12px; padding: 9px 0; border-bottom: 1px dashed var(--paper-line); }
.eng-rec__dl dt { color: var(--paper-ink-2); }
.eng-rec__dl dd { margin: 0; color: var(--paper-ink); overflow-wrap: anywhere; }
.eng-rec__dl .is-check dd b { color: var(--purple); }
.eng-rec__dl .is-check { background: rgba(100, 13, 95, 0.06); margin: 0 -20px; padding-inline: 20px; }
.eng-rec__dl .is-est dd { color: var(--purple); }
.eng-rec .eng-cap { color: var(--paper-ink-2); padding: 0 20px; }
.eng-guar { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: 1fr 1fr; column-gap: clamp(20px, 3vw, 40px); }
.eng-guar li { display: grid; gap: 8px; align-content: start; padding: 16px 0 20px; border-top: 1px solid var(--line); }
.eng-guar__k { font-size: 11px; color: var(--amber); padding-top: 4px; }
.eng-guar p { font: 400 17px/1.5 var(--font-text); color: var(--ink); }
.eng-anchor { margin-top: 28px; padding: 22px 24px; border: 1px solid color-mix(in srgb, var(--amber) 45%, transparent); border-radius: var(--radius); background: color-mix(in srgb, var(--amber) 6%, transparent); }
.eng-anchor__k { font-size: 11px; color: var(--amber); margin-bottom: 10px; }
.eng-anchor__v { font: 400 clamp(18px, 1.5vw, 21px)/1.4 var(--font-display); letter-spacing: -0.015em; margin-bottom: 16px; }
.eng-prov__ops { margin-top: clamp(40px, 5vw, 64px); border-bottom: 1px solid var(--line); }
.eng-more { margin-top: clamp(48px, 6vw, 88px); }
@media (max-width: 1000px) { .eng-prov__grid { grid-template-columns: 1fr; } }
@media (max-width: 560px) {
  .eng-rec__dl div { grid-template-columns: 1fr; gap: 2px; }
  .eng-guar { grid-template-columns: 1fr; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .js .eng-lanes[data-reveal] .eng-seg, .js .eng-lanes[data-reveal] .eng-ticks, .js .eng-ring[data-reveal] .eng-arc,
  .js .eng-mbars[data-reveal] .eng-mbars__stack, .js .eng-scales[data-reveal] .eng-sbar__fill {
    transform: none !important; opacity: 1 !important; stroke-dashoffset: 0 !important; transition: none !important;
  }
  .js .eng-lanes[data-reveal] .eng-dec { transform: rotate(45deg) !important; opacity: 1 !important; transition: none !important; }
  .eng-field .c, .eng-k__bar i { transition: none !important; }
  .eng-field.is-scan .eng-field__scan { animation: none; }
}

/* class rows: number group participates in the row grid on desktop, becomes its own grid on narrow screens */
.eng-k__nums { display: contents; }
@media (max-width: 1100px) {
  .eng-k__sum { grid-template-columns: 52px minmax(0, 1fr) 18px; grid-template-areas: "cls tool chev" "nums nums nums"; row-gap: 14px; }
  .eng-k__nums { grid-area: nums; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px 14px; }
  .eng-k__nums .eng-k__num, .eng-k__nums .eng-k__cost { text-align: left; display: grid; gap: 5px; white-space: normal; }
  .eng-k__nums [data-l]::before { content: attr(data-l); font: 400 10px/1 var(--font-mono); color: var(--ink-3); text-transform: uppercase; letter-spacing: 0.03em; }
  .eng-k__nums .eng-k__cost { grid-column: 1 / -1; grid-template-columns: minmax(0, 1fr) 60px; }
  .eng-k__nums .eng-k__cost::before { grid-column: 1 / -1; }
  .eng-k__cost b { text-align: right; }
}

/* ---------- document section index (depth 4) ---------- */
.eng-toc { margin-top: clamp(40px, 5vw, 64px); padding-top: 22px; border-top: 1px solid var(--line-2); }
.eng-toc__k { font-size: 12px; color: var(--ink-3); margin-bottom: 18px; }
.eng-toc__lvl { color: var(--purple-ink); font-weight: 500; margin-right: 6px; }
.eng-toc__list { list-style: none; padding: 0; margin: 0; columns: 3 260px; column-gap: 40px; }
.eng-toc__list li { break-inside: avoid; }
.eng-toc__list a { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 8px; padding: 9px 0; border-bottom: 1px solid var(--line); font: 400 15px/1.35 var(--font-text); color: var(--ink-2); text-decoration: none; transition: color 0.2s; }
.eng-toc__list a .mono { font-size: 11.5px; color: var(--purple-ink); padding-top: 2px; }
.eng-toc__list a:hover { color: var(--ink); }
.eng-toc__list .is-sub a { padding-left: 16px; font-size: 14px; color: var(--ink-3); }

/* ---------- job classes: header ticks, units, compact mobile ---------- */
.eng-k__costh { display: grid; grid-template-columns: minmax(0, 1fr) 52px; column-gap: 10px; row-gap: 6px; }
.eng-k__costh > span:first-child { grid-column: 1 / -1; }
.eng-k__ticks { position: relative; height: 12px; text-transform: none; letter-spacing: 0; }
.eng-k__ticks i { position: absolute; left: calc(var(--x) * 100%); transform: translateX(-50%); font: 400 10px/1 var(--font-mono); font-style: normal; color: var(--ink-3); white-space: nowrap; }
.eng-k__ticks i:first-child { transform: none; }
.eng-k__ticks i:last-child { transform: translateX(-100%); }
.eng-k__head { align-items: end; }
.eng-k__head > span { white-space: nowrap; }
.eng-k__head > .eng-k__2l { white-space: normal; line-height: 1.3; }
.eng-k__unit { display: none; }
.eng-k__tpm { display: none; }
@media (max-width: 1100px) {
  .eng-k__nums { grid-template-columns: auto auto auto minmax(0, 1fr); gap: 10px 14px; align-items: center; }
  .eng-k__nums [data-l]::before { content: none; }
  .eng-k__nums .eng-k__num { display: block; font-size: 12px; color: var(--ink-2); }
  .eng-k__nums .eng-k__num + .eng-k__num::before { content: "·"; margin-right: 10px; color: var(--ink-3); }
  .eng-k__unit { display: inline; color: var(--ink-3); }
  .eng-k__nums .eng-k__tp { display: none; }
  .eng-k__nums .eng-k__cost { grid-column: 1 / -1; grid-template-columns: minmax(0, 1fr) 96px; display: grid; }
  .eng-k__cost b { white-space: nowrap; }
  .eng-k__nums .eng-k__cost::before { content: none; }
  .eng-k__tpm { display: block; grid-column: 1 / -1; font-size: 12px; color: var(--ink-2); padding: 10px 12px; background: var(--bg-raise); border-radius: 3px; }
  .eng-k__tpm span { display: block; color: var(--ink-3); font-size: 10.5px; margin-bottom: 4px; text-transform: uppercase; }
  .eng-k__tpm b { color: var(--ink); font-weight: 500; }
  .eng-k__sum { padding: 16px 0; row-gap: 10px; }
  .eng-k__cls { font-size: 24px; }
}

/* ---------- split header: headline left, content right (round 4 density) ---------- */
.eng-split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(32px, 5vw, 88px); align-items: start; }
.eng-split__side { padding-top: clamp(30px, 3vw, 44px); }
.eng-split--cost { grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); }
.eng-split .eng-qs { grid-template-columns: 1fr; margin-top: 0; }
.eng-split .eng-q { grid-template-columns: 56px minmax(0, 1fr); column-gap: 14px; row-gap: 6px; padding: 16px 18px; }
.eng-split .eng-q__n { grid-row: span 3; font-size: clamp(30px, 2.6vw, 40px); }
.eng-split .eng-q__text { font-size: clamp(17px, 1.4vw, 20px); }
.eng-split--cost .eng-figs__item { padding: 14px 0 16px; }
.eng-split--cost .eng-figs__item:first-child { padding-top: 0; border-top: 0; }
.eng-split--cost .eng-figs__v { font-size: clamp(42px, 4.2vw, 68px); }
.eng-split--prov .eng-guar li:nth-child(-n + 2) { border-top: 0; padding-top: 0; }
.eng-prov .eng-anchor { margin-top: clamp(28px, 3vw, 40px); }
.eng-more__list { grid-template-columns: 1fr 1fr; column-gap: clamp(24px, 4vw, 56px); }
.eng-more__list .deeper:nth-last-child(2) { border-bottom: 1px solid var(--line); }
@media (max-width: 1100px) {
  .eng-split { grid-template-columns: 1fr; gap: 28px; }
  .eng-split__side { padding-top: 0; }
  .eng-split--prov .eng-guar li:nth-child(-n + 2) { border-top: 1px solid var(--line); padding-top: 16px; }
  .eng-split--cost .eng-figs__item:first-child { padding-top: 14px; border-top: 1px solid var(--line-2); }
}
@media (max-width: 860px) {
  .eng-more__list { grid-template-columns: 1fr; }
  .eng-more__list .deeper:nth-last-child(2) { border-bottom: 0; }
}

/* ---------- band head: headline left, lead right on wide screens ---------- */
@media (min-width: 1101px) {
  .eng-head { display: grid; grid-template-columns: minmax(0, 1fr) minmax(300px, 40ch); column-gap: clamp(32px, 4vw, 72px); align-items: end; }
  .eng-head > .kicker { grid-column: 1 / -1; }
  .page-engine .section .eng-head > h2 + .lead { margin-top: 0; padding-bottom: 0.35em; max-width: none; font-size: clamp(18px, 1.45vw, 22px); }
}

/* round 5: "how" link under the promise bars */
.eng-howlink { display: inline-flex; align-items: baseline; gap: 12px; margin-top: 28px; font: 400 clamp(20px, 1.8vw, 26px)/1.2 var(--font-display); letter-spacing: -0.025em; color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--line-2); padding-bottom: 8px; transition: border-color 0.2s, color 0.2s; }
.eng-howlink .mono { font-size: 12px; color: var(--amber); letter-spacing: 0; }
.eng-howlink:hover { color: var(--amber-ink); border-bottom-color: var(--amber); }
.eng-howlink + .eng-srcrow { margin-top: 20px; }