/* ============================================================
   CortexQuant Lab — Five Engines
   Design language: technical blueprint / engineering schematic.
   Light cream drafting paper, hairline frames, spec plates.
   ============================================================ */

:root {
  --paper:      #f4f1ea;
  --paper-hi:   #fbf9f3;
  --paper-lo:   #eae4d7;
  --ink:        #1b2430;
  --ink-2:      #5a6672;
  --ink-3:      #626c78;
  --rule:       #d5cfc0;
  --rule-2:     #c3bba9;
  --cyan:       #0b7285;
  --cyan-soft:  #0b728518;
  --cyan-line:  #0b728529;
  --signal:     #c2410c;
  --signal-soft:#c2410c14;

  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --sans: "Archivo", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

  --sheet-max: 1180px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.68;
  color: var(--ink);
  background-color: var(--paper);
  /* layered: paper grain -> fine grid -> major grid -> warm wash */
  background-image:
    url("data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20width='160'%20height='160'%3E%3Cfilter%20id='g'%3E%3CfeTurbulence%20type='fractalNoise'%20baseFrequency='0.82'%20numOctaves='3'%20stitchTiles='stitch'/%3E%3CfeColorMatrix%20type='saturate'%20values='0'/%3E%3C/filter%3E%3Crect%20width='100%25'%20height='100%25'%20filter='url(%23g)'%20opacity='0.22'/%3E%3C/svg%3E"),
    repeating-linear-gradient(0deg, var(--cyan-line) 0 1px, transparent 1px 22px),
    repeating-linear-gradient(90deg, var(--cyan-line) 0 1px, transparent 1px 22px),
    repeating-linear-gradient(0deg, var(--cyan-soft) 0 1px, transparent 1px 110px),
    repeating-linear-gradient(90deg, var(--cyan-soft) 0 1px, transparent 1px 110px),
    radial-gradient(125% 85% at 12% -5%, #fdfbf6 0%, var(--paper) 46%, var(--paper-lo) 100%);
  background-attachment: fixed, fixed, fixed, fixed, fixed, fixed;
}
img { max-width: 100%; height: auto; display: block; }

a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ---------- focus ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- skip link ---------- */
.skip-link {
  position: absolute; left: 12px; top: -60px;
  z-index: 100;
  background: var(--ink); color: var(--paper-hi);
  padding: 12px 18px; border-radius: 3px;
  font-family: var(--mono); font-size: .8rem; letter-spacing: .06em; text-transform: uppercase;
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 12px; text-decoration: none; }

/* ---------- small-caps technical label ---------- */
.label {
  font-family: var(--mono);
  font-size: .7rem;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.label--cyan { color: var(--cyan); }
.label--signal { color: var(--signal); }

/* ---------- layout shell ---------- */
.shell {
  width: min(100% - 2.6rem, var(--sheet-max));
  margin-inline: auto;
}

/* ============================================================
   HEADER RAIL — drawing-sheet title strip
   ============================================================ */
.rail {
  position: sticky; top: 0; z-index: 40;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(7px);
  border-bottom: 1px solid var(--rule);
}
.rail__inner {
  width: min(100% - 2.6rem, var(--sheet-max));
  margin-inline: auto;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; min-height: 62px;
}
.rail__mark {
  display: inline-flex; align-items: center; gap: .6rem;
  font-family: var(--mono); font-weight: 600; font-size: .95rem;
  letter-spacing: .04em; color: var(--ink); text-transform: uppercase;
}
.rail__mark:hover { text-decoration: none; }
.rail__mark span { color: var(--cyan); }
.rail__tick {
  width: 11px; height: 11px; flex: none;
  border: 2px solid var(--cyan);
  position: relative;
}
.rail__tick::after {
  content: ""; position: absolute; inset: 3px; background: var(--signal);
}
.rail__nav { display: flex; flex-wrap: wrap; gap: .35rem .2rem; }
.rail__nav a {
  font-family: var(--mono); font-size: .74rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ink-2);
  padding: .72rem .7rem; min-height: 44px;
  display: inline-flex; align-items: center;
  border-bottom: 2px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.rail__nav a:hover { color: var(--cyan); border-bottom-color: var(--cyan); text-decoration: none; }

/* ============================================================
   FRAME — hairline drafting frame with corner tick marks
   ============================================================ */
.frame {
  position: relative;
  border: 1px solid var(--rule);
  background: color-mix(in srgb, var(--paper-hi) 62%, transparent);
}
.frame::before {
  content: ""; position: absolute; inset: -1px; pointer-events: none;
  --tick: var(--cyan);
  background:
    linear-gradient(var(--tick), var(--tick)) left  top    / 15px 2px no-repeat,
    linear-gradient(var(--tick), var(--tick)) left  top    / 2px 15px no-repeat,
    linear-gradient(var(--tick), var(--tick)) right top    / 15px 2px no-repeat,
    linear-gradient(var(--tick), var(--tick)) right top    / 2px 15px no-repeat,
    linear-gradient(var(--tick), var(--tick)) left  bottom / 15px 2px no-repeat,
    linear-gradient(var(--tick), var(--tick)) left  bottom / 2px 15px no-repeat,
    linear-gradient(var(--tick), var(--tick)) right bottom / 15px 2px no-repeat,
    linear-gradient(var(--tick), var(--tick)) right bottom / 2px 15px no-repeat;
}
.frame--risk::before { --tick: var(--signal); }

/* dimension-line rule */
.dim {
  position: relative; height: 1px; background: var(--rule-2);
  margin: 2.4rem 0;
}
.dim::before, .dim::after {
  content: ""; position: absolute; top: -5px; width: 1px; height: 11px;
  background: var(--rule-2);
}
.dim::before { left: 0; } .dim::after { right: 0; }

/* ============================================================
   HERO
   ============================================================ */
.hero { padding: 2.4rem 0 .6rem; }
.hero__sheet { padding: clamp(1.1rem, 3vw, 2rem); }

.sheet-meta {
  display: flex; flex-wrap: wrap; gap: .5rem 1.6rem;
  padding-bottom: 1rem; border-bottom: 1px solid var(--rule);
  margin-bottom: 1.9rem;
}
.sheet-meta span { display: inline-flex; align-items: center; gap: .5rem; }
.sheet-meta b { color: var(--ink); font-weight: 600; }

.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.62fr) minmax(0, 1fr);
  gap: clamp(1.4rem, 4vw, 3.2rem);
  align-items: start;
}
.hero__eyebrow { margin: 0 0 .9rem; }

h1 {
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(2.05rem, 5.4vw, 3.5rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0 0 1.15rem;
  max-width: 20ch;
}
h1 em {
  font-style: normal;
  color: var(--cyan);
  box-shadow: inset 0 -0.16em 0 var(--cyan-soft);
}
.hero__lede {
  font-size: 1.115rem; color: var(--ink-2); max-width: 56ch; margin: 0 0 1.4rem;
}
.hero__lede strong { color: var(--ink); font-weight: 600; }

.hero__anno {
  display: flex; flex-wrap: wrap; gap: .55rem 1.5rem;
  border-top: 1px dashed var(--rule-2); padding-top: 1.05rem;
}
.hero__anno span {
  font-family: var(--mono); font-size: .73rem; letter-spacing: .06em;
  color: var(--ink-2); display: inline-flex; align-items: center; gap: .45rem;
}
.hero__anno svg { flex: none; color: var(--cyan); }

/* spec block (right column) */
.spec { padding: 1.2rem 1.25rem; }
.spec__title { margin: 0 0 .9rem; padding-bottom: .7rem; border-bottom: 1px solid var(--rule); }
.spec dl { margin: 0; }
.spec__row {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 1rem; padding: .62rem 0; border-bottom: 1px dashed var(--rule);
}
.spec__row:last-child { border-bottom: 0; }
.spec__row dt {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .07em;
  text-transform: uppercase; color: var(--ink-2);
}
.spec__row dd {
  margin: 0; font-family: var(--mono); font-weight: 600; font-size: 1rem;
  color: var(--ink); text-align: right;
}
.spec__row dd.hot { color: var(--signal); }

.hero__media { margin: 2rem 0 0; }
.hero__media img { width: 100%; }
figcaption {
  font-family: var(--mono); font-size: .76rem; line-height: 1.55;
  color: var(--ink-2); padding: .7rem .2rem 0;
  border-top: 1px solid var(--rule); margin-top: .9rem;
}

/* ============================================================
   DOSSIER: parts-list TOC + prose
   ============================================================ */
.dossier {
  display: grid;
  grid-template-columns: 218px minmax(0, 1fr);
  gap: clamp(1.6rem, 4vw, 3.4rem);
  padding: 3rem 0 1rem;
  align-items: start;
}
.dossier > * { min-width: 0; }
.parts { position: sticky; top: 84px; }
.parts__head {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .18em;
  text-transform: uppercase; color: var(--cyan);
  padding-bottom: .6rem; margin: 0 0 .5rem; border-bottom: 2px solid var(--cyan);
}
.parts ol { list-style: none; margin: 0; padding: 0; counter-reset: part; }
.parts li { border-bottom: 1px dashed var(--rule); }
.parts a {
  display: flex; gap: .7rem; align-items: baseline;
  padding: .62rem .2rem; min-height: 44px;
  font-size: .84rem; color: var(--ink-2);
  transition: color .2s var(--ease), padding-left .2s var(--ease);
}
.parts a::before {
  counter-increment: part;
  content: counter(part, decimal-leading-zero);
  font-family: var(--mono); font-size: .7rem; color: var(--ink-3); flex: none;
}
.parts a:hover { color: var(--cyan); padding-left: .5rem; text-decoration: none; }
.parts a.is-active { color: var(--cyan); font-weight: 600; }
.parts a.is-active::before { color: var(--signal); }

/* ---------- prose ---------- */
.prose { max-width: none; }
.prose > section > * { max-width: 74ch; }
.prose .pipeline { max-width: none; }
.prose section { scroll-margin-top: 88px; }
h2 {
  font-family: var(--sans); font-weight: 700;
  font-size: clamp(1.5rem, 3.1vw, 2.05rem);
  line-height: 1.16; letter-spacing: -0.015em;
  margin: 3.1rem 0 1rem; padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
}
h2:first-of-type { margin-top: .4rem; }
h2 .h2-num {
  display: block; font-family: var(--mono); font-weight: 500;
  font-size: .72rem; letter-spacing: .2em; text-transform: uppercase;
  color: var(--cyan); margin-bottom: .55rem;
}
h3 {
  font-family: var(--sans); font-weight: 600; font-size: 1.16rem;
  letter-spacing: -0.005em; margin: 2rem 0 .6rem; color: var(--ink);
}
h3::before { content: "▸ "; color: var(--cyan); font-family: var(--mono); }
p { margin: 0 0 1.05rem; }
.prose .lede { font-size: 1.12rem; color: var(--ink-2); }
ul, ol { margin: 0 0 1.05rem; padding-left: 1.35rem; }
li { margin-bottom: .45rem; }
li::marker { color: var(--cyan); font-family: var(--mono); }
strong { font-weight: 600; }

/* ============================================================
   PLATE — one numbered engine per frame
   ============================================================ */
.plate {
  margin: 2.6rem 0;
  padding: clamp(1.1rem, 2.6vw, 1.85rem);
}
.plate__head {
  display: flex; flex-wrap: wrap; align-items: baseline;
  gap: .8rem 1.2rem;
  padding-bottom: .95rem; margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--rule);
}
.plate__no {
  font-family: var(--mono); font-weight: 700; font-size: .82rem;
  letter-spacing: .1em; color: var(--paper-hi); background: var(--cyan);
  padding: .34rem .6rem 0.28rem; flex: none;
}
.plate--risk .plate__no { background: var(--signal); }
.plate__title {
  margin: 0; font-family: var(--sans); font-weight: 700;
  font-size: clamp(1.18rem, 2.6vw, 1.5rem); letter-spacing: -.012em;
}
.plate__sub {
  margin: 0; flex-basis: 100%;
  font-family: var(--mono); font-size: .75rem; letter-spacing: .05em; color: var(--ink-2);
}
.plate--risk .plate__sub { color: var(--signal); }

/* input → process → output annotation strip */
.flowstrip {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0; margin: 0 0 1.4rem; border: 1px solid var(--rule);
}
.flowstrip__cell { padding: .8rem .95rem; border-right: 1px solid var(--rule); }
.flowstrip__cell:last-child { border-right: 0; }
.flowstrip__cell .label { display: block; margin-bottom: .35rem; }
.flowstrip__cell p { margin: 0; font-size: .9rem; color: var(--ink-2); }
.plate--risk .flowstrip__cell:last-child .label { color: var(--signal); }

/* ============================================================
   TABLES
   ============================================================ */
.table-wrap { overflow-x: auto; margin: 1.5rem 0; border: 1px solid var(--rule); }
table { border-collapse: collapse; width: 100%; min-width: 520px; font-size: .93rem; }
caption {
  text-align: left; font-family: var(--mono); font-size: .72rem;
  letter-spacing: .14em; text-transform: uppercase; color: var(--ink-2);
  padding: .8rem .95rem; border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--cyan) 5%, transparent);
}
th, td { text-align: left; padding: .68rem .95rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
thead th {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ink); font-weight: 600;
  background: color-mix(in srgb, var(--paper-hi) 80%, transparent);
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: color-mix(in srgb, var(--cyan) 4%, transparent); }
td code, th code { font-family: var(--mono); font-size: .86em; color: var(--cyan); }

/* ============================================================
   FIGURES
   ============================================================ */
.inline-fig { margin: 1.8rem 0; }
.inline-fig .frame { padding: 0; overflow: hidden; }
.inline-fig img { width: 100%; }

/* ============================================================
   CALLOUT
   ============================================================ */
.callout {
  position: relative;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--cyan);
  background: color-mix(in srgb, var(--cyan) 5%, transparent);
  padding: 1.05rem 1.2rem .8rem; margin: 1.7rem 0;
}
.callout--risk { border-left-color: var(--signal); background: var(--signal-soft); }
.callout__label { display: block; margin-bottom: .45rem; }
.callout p { margin: 0; font-size: .98rem; }

/* ============================================================
   PIPELINE — CSS assembly-line diagram
   ============================================================ */
.pipeline {
  display: flex; align-items: stretch; flex-wrap: nowrap;
  margin: 1.9rem 0; padding: 1.3rem 1rem;
  border: 1px solid var(--rule);
  background: color-mix(in srgb, var(--paper-hi) 55%, transparent);
  overflow-x: auto;
}
.pipe-node {
  flex: 1 1 0; min-width: 116px;
  border: 1px solid var(--rule-2);
  background: var(--paper-hi);
  padding: .85rem .7rem;
  position: relative;
  transition: transform .3s var(--ease), border-color .3s var(--ease);
}
.pipe-node::before {
  content: ""; position: absolute; left: -1px; top: -1px;
  width: 12px; height: 2px; background: var(--cyan);
}
.pipe-node::after {
  content: ""; position: absolute; left: -1px; top: -1px;
  width: 2px; height: 12px; background: var(--cyan);
}
.pipe-node:hover { transform: translateY(-3px); border-color: var(--cyan); }
.pipe-node--risk::before, .pipe-node--risk::after { background: var(--signal); }
.pipe-node--risk { border-color: color-mix(in srgb, var(--signal) 45%, var(--rule-2)); }
.pipe-node--end::before, .pipe-node--end::after { background: var(--ink); }
.pipe-node__idx {
  display: block; font-family: var(--mono); font-size: .68rem;
  letter-spacing: .12em; color: var(--ink-3); margin-bottom: .35rem;
}
.pipe-node__name {
  display: block; font-family: var(--mono); font-weight: 600;
  font-size: .82rem; line-height: 1.28; color: var(--ink);
}
.pipe-node__io {
  display: block; margin-top: .5rem; font-family: var(--mono);
  font-size: .66rem; letter-spacing: .06em; color: var(--ink-3);
}
.pipe-node--risk .pipe-node__name { color: var(--signal); }
.pipe-flow {
  flex: 0 0 34px; display: flex; align-items: center; justify-content: center;
  color: var(--cyan);
}
.pipe-flow svg { display: block; }

/* ============================================================
   FAQ
   ============================================================ */
.faq { margin: 1.4rem 0 0; border-top: 1px solid var(--rule); }
.faq details { border-bottom: 1px solid var(--rule); }
.faq summary {
  cursor: pointer; list-style: none;
  display: flex; align-items: baseline; gap: .85rem;
  padding: 1.05rem .2rem; min-height: 44px;
  font-weight: 600; font-size: 1.02rem; color: var(--ink);
  transition: color .2s var(--ease);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before {
  content: "+"; flex: none; font-family: var(--mono); font-weight: 500;
  font-size: 1.05rem; color: var(--cyan); width: 1rem;
  transition: transform .28s var(--ease);
}
.faq details[open] summary::before { content: "–"; transform: rotate(180deg); }
.faq summary:hover { color: var(--cyan); }
.faq__body { padding: 0 0 1.15rem 1.85rem; }
.faq__body p { margin: 0; color: var(--ink-2); }

/* ============================================================
   RELATED
   ============================================================ */
.related { display: grid; gap: 0; border-top: 1px solid var(--rule); margin-top: 1rem; }
.related a {
  display: block; padding: 1rem .3rem; border-bottom: 1px solid var(--rule);
  transition: padding-left .22s var(--ease), background .22s var(--ease);
}
.related a:hover { padding-left: .9rem; background: color-mix(in srgb, var(--cyan) 5%, transparent); text-decoration: none; }
.related__kicker {
  display: block; font-family: var(--mono); font-size: .68rem;
  letter-spacing: .14em; text-transform: uppercase; color: var(--cyan); margin-bottom: .3rem;
}
.related__title { color: var(--ink); font-size: .96rem; }

/* ============================================================
   FOOTER
   ============================================================ */
.foot {
  margin-top: 3.4rem; border-top: 2px solid var(--ink);
  background: color-mix(in srgb, var(--ink) 4%, transparent);
  padding: 2.6rem 0 2.2rem;
}
.foot__brand {
  font-family: var(--mono); font-weight: 700; letter-spacing: .05em;
  font-size: 1.05rem; text-transform: uppercase; margin: 0 0 .5rem;
}
.foot__brand span { color: var(--cyan); }
.foot__blurb { color: var(--ink-2); max-width: 62ch; margin: 0 0 1.8rem; font-size: .96rem; }
.foot__net-title { margin: 0 0 .8rem; }
.linknet { list-style: none; margin: 0 0 2rem; padding: 0; display: grid; gap: 0 2.2rem; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.linknet li { border-bottom: 1px dashed var(--rule); }
.linknet a {
  display: flex; align-items: baseline; justify-content: space-between; gap: 1rem;
  padding: .6rem .1rem; min-height: 44px;
  font-size: .88rem; color: var(--ink);
  transition: color .2s var(--ease), padding-left .2s var(--ease);
}
.linknet a:hover { color: var(--cyan); padding-left: .5rem; text-decoration: none; }
.linknet a span { font-family: var(--mono); font-size: .7rem; color: var(--ink-3); flex: none; }
.foot__legal { border-top: 1px solid var(--rule); padding-top: 1.3rem; }
.foot__legal p { font-size: .8rem; color: var(--ink-2); margin: 0 0 .6rem; max-width: 88ch; }

/* ============================================================
   REVEAL (progressive enhancement)
   ============================================================ */
.js .reveal { opacity: 0; transform: translateY(14px); }
.js .reveal.in { opacity: 1; transform: none; transition: opacity .6s var(--ease), transform .6s var(--ease); }
@media (prefers-reduced-motion: reduce) {
  .js .reveal { opacity: 1; transform: none; }
  .pipe-node { transition: none; }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .hero__grid { grid-template-columns: minmax(0, 1fr); }
  .spec { order: 2; }
  .dossier { grid-template-columns: minmax(0, 1fr); }
  .parts { position: static; }
  .parts ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 1.4rem; }
  .linknet { grid-template-columns: minmax(0, 1fr); }
  /* the rail wraps to two rows at this width */
  .prose section { scroll-margin-top: 118px; }
}
@media (max-width: 620px) {
  body { font-size: 1rem; }
  .rail__nav a { padding: .6rem .55rem; font-size: .68rem; }
  .parts ol { grid-template-columns: minmax(0, 1fr); }
  .prose section { scroll-margin-top: 150px; }
  .flowstrip { grid-template-columns: 1fr; }
  .flowstrip__cell { border-right: 0; border-bottom: 1px solid var(--rule); }
  .flowstrip__cell:last-child { border-bottom: 0; }
  .pipeline { flex-direction: column; align-items: stretch; overflow-x: visible; }
  .pipe-flow { flex: 0 0 30px; transform: rotate(90deg); }
  .pipe-node { min-width: 0; }
}

/* ---------- brand logo ---------- */
/* Sized relative to the adjacent wordmark (em) with an absolute cap, so each
   site's own type scale governs the mark instead of one fixed pixel height. */
.brand-logo {
  display: inline-block;
  height: min(1.1em, 18px);
  width: auto;
  margin-right: 0.45em;
  vertical-align: -0.22em;
}
.foot__brand .brand-logo,
.foot__wordmark .brand-logo,
.foot__logo .brand-logo {
  height: min(1.3em, 26px);
  margin-right: 0.45em;
  vertical-align: -0.24em;
}
@media (max-width: 640px) {
  .brand-logo { height: min(1.05em, 16px); margin-right: 0.35em; }
  .foot__brand .brand-logo,
  .foot__wordmark .brand-logo { height: min(1.2em, 22px); }
}