/* ==========================================================================
   64ARC — The architecture of intelligent business
   site.css  ·  Design system + components + page styles
   --------------------------------------------------------------------------
   Contents
     01  Tokens
     02  Reset & base
     03  Typography
     04  Layout
     05  Buttons & links
     06  Header / navigation
     07  Sections & surfaces
     08  Cards & primitives
     09  Diagrams
     10  Motion / reveal
     11  Forms
     12  Footer
     13  Responsive
   ========================================================================== */

/* ==========================================================================
   01  TOKENS
   ========================================================================== */

:root {
  /* ---- Brand palette (per brief) ---- */
  --carbon:        #111318;   /* primary typography / dark surfaces */
  --ivory:         #F4F1EA;   /* primary light surface              */
  --signal:        #5367FF;   /* intelligence / interaction         */
  --soft-grey:     #E7E8EC;   /* rules / borders / scaffolding      */

  /* ---- Derived surfaces ---- */
  --carbon-raised: #181B22;
  --carbon-sunken: #0C0E12;
  --carbon-line:   #262A34;
  --carbon-line-2: #343947;
  --ivory-raised:  #FBFAF6;
  --ivory-sunken:  #EDEAE1;

  /* ---- Ink ---- */
  /* ---- Ink ----
     Every value below is used for real text, so each clears WCAG AA (4.5:1)
     against the surfaces it actually appears on. Do not lighten these. */
  --ink:           #111318;
  --ink-muted:     #5C6272;   /* 5.40:1 on ivory                        */
  --ink-faint:     #636978;   /* 4.87 ivory · 4.57 sunken · 5.26 raised  */
  --ink-inv:       #F4F1EA;
  --ink-inv-muted: #A7ADBB;
  --ink-inv-faint: #808795;   /* 5.15:1 on carbon                       */

  /* ---- Signal variants ---- */
  --signal-ink:     #3B4CE0;   /* small text on light  — 5.65:1 on ivory  */
  --signal-on-dark: #7A89FF;   /* small text on carbon — 6.06:1           */
  --signal-soft:   rgba(83, 103, 255, .10);
  --signal-line:   rgba(83, 103, 255, .34);
  --signal-glow:   rgba(83, 103, 255, .55);

  /* ---- Type ---- */
  --font-display: "Space Grotesk", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-body:    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono:    "IBM Plex Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  /* Fluid type scale — engineered, not cramped */
  --t-hero:    clamp(2.125rem, 1.1rem + 4.4vw, 5rem);     /* 34 → 80px  */
  --t-h1:      clamp(2.375rem, 1.35rem + 3.9vw, 4rem);    /* 38 → 64px  */
  --t-h2:      clamp(2rem, 1.25rem + 2.8vw, 3.25rem);     /* 32 → 52px  */
  --t-h3:      clamp(1.375rem, 1.10rem + 1.0vw, 1.875rem);/* 22 → 30px  */
  --t-h4:      clamp(1.125rem, 1.03rem + .35vw, 1.3125rem);
  --t-lead:    clamp(1.125rem, 1.02rem + .45vw, 1.4375rem);
  --t-body:    clamp(1rem, .96rem + .18vw, 1.1875rem);    /* 16 → 19px  */
  --t-small:   .9375rem;
  --t-label:   .75rem;

  /* ---- Space ---- */
  --gutter:     clamp(1.25rem, .6rem + 2.4vw, 2.5rem);
  --wrap:       1280px;
  --wrap-text:  760px;
  --section-y:  clamp(5rem, 3rem + 8vw, 10rem);
  --section-y-lg: clamp(6.5rem, 3.5rem + 10vw, 13rem);

  /* ---- Form ---- */
  --radius:    10px;
  --radius-sm: 6px;
  --radius-lg: 14px;

  /* ---- Motion ---- */
  --ease:      cubic-bezier(.22, .61, .36, 1);
  --ease-out:  cubic-bezier(.16, 1, .3, 1);
  --dur:       .6s;

  --header-h:  76px;
}

/* ==========================================================================
   02  RESET & BASE
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 24px);
}

body {
  margin: 0;
  background: var(--ivory);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: var(--t-body);
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  font-feature-settings: "kern" 1, "liga" 1, "calt" 1;
}

body.is-locked { overflow: hidden; }

img, svg { display: block; max-width: 100%; }
svg { height: auto; }

hr {
  border: 0;
  border-top: 1px solid var(--soft-grey);
  margin: 0;
}

::selection { background: var(--signal); color: #fff; }

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 999;
  background: var(--carbon);
  color: var(--ivory);
  padding: .875rem 1.25rem;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .08em;
  text-transform: uppercase;
  text-decoration: none;
}
.skip-link:focus { left: 1rem; top: 1rem; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ==========================================================================
   03  TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.04;
  letter-spacing: -.025em;
  margin: 0;
  text-wrap: balance;
}

.t-hero  { font-size: var(--t-hero); line-height: 1.0;  letter-spacing: -.035em; }
.t-h1    { font-size: var(--t-h1);   line-height: 1.03; letter-spacing: -.032em; }
.t-h2    { font-size: var(--t-h2);   line-height: 1.06; letter-spacing: -.028em; }
.t-h3    { font-size: var(--t-h3);   line-height: 1.15; letter-spacing: -.022em; }
.t-h4    { font-size: var(--t-h4);   line-height: 1.3;  letter-spacing: -.015em; }

p { margin: 0 0 1.15em; text-wrap: pretty; }
p:last-child { margin-bottom: 0; }

.lead {
  font-size: var(--t-lead);
  line-height: 1.5;
  color: var(--ink-muted);
  letter-spacing: -.012em;
}
/* A lead paragraph always needs air after the headline it follows. */
:is(h1, h2, h3) + .lead { margin-top: 1.5rem; }

.muted     { color: var(--ink-muted); }
.faint     { color: var(--ink-faint); }
.measure   { max-width: 62ch; }
.measure-s { max-width: 48ch; }
.measure-l { max-width: 72ch; }

/* Technical label — the 64-bit nod */
.label {
  display: inline-flex;
  align-items: center;
  gap: .6em;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  line-height: 1;
}
.label--signal { color: var(--signal-ink); }
/* As a standalone eyebrow the label carries its own spacing; inline uses
   (.ai-ask, .principle) override this below. */
p.label { margin-bottom: 1.5rem; }
.label::before {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
  opacity: .5;
  flex: none;
}
.label--bare::before { display: none; }

.label-index {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  color: var(--signal-ink);
  font-weight: 500;
}

/* Emphasis inside headlines */
.hl { color: var(--signal); }
em.hl, .hl em { font-style: normal; }

/* Rule that reads as architectural scaffolding */
.rule {
  height: 1px;
  background: var(--soft-grey);
  border: 0;
  margin: 0;
}

/* ==========================================================================
   04  LAYOUT
   ========================================================================== */

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.wrap--narrow { max-width: 980px; }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1.25rem, .8rem + 1.6vw, 2.5rem);
}

.stack > * + * { margin-top: var(--stack, 1.5rem); }

/* Section header block: label + heading + lead */
.section-head {
  max-width: 900px;
  margin-bottom: clamp(2.5rem, 1.5rem + 3vw, 4rem);
}
.section-head .label { margin-bottom: 1.75rem; }
.section-head .lead  { margin-top: 1.5rem; }
.section-head:last-child { margin-bottom: 0; }

.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(2rem, 1rem + 4vw, 5rem);
  align-items: start;
}
/* Label column + content column: the content side needs the room. */
.split--sticky { grid-template-columns: minmax(0, 4fr) minmax(0, 7fr); }
.split--sticky > :first-child { position: sticky; top: calc(var(--header-h) + 48px); }

/* Definition rows inside a split are already narrow — stack them. */
.split .rows > div { grid-template-columns: 1fr; gap: .5rem; }

/* ==========================================================================
   05  BUTTONS & LINKS
   ========================================================================== */

a { color: inherit; }

.btn {
  --btn-bg: var(--carbon);
  --btn-fg: var(--ivory);
  --btn-bd: var(--carbon);
  display: inline-flex;
  align-items: center;
  gap: .75rem;
  padding: 1rem 1.5rem;
  background: var(--btn-bg);
  color: var(--btn-fg);
  border: 1px solid var(--btn-bd);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: .9375rem;
  font-weight: 500;
  letter-spacing: -.005em;
  text-decoration: none;
  cursor: pointer;
  transition: background .35s var(--ease), color .35s var(--ease),
              border-color .35s var(--ease), transform .35s var(--ease);
  white-space: nowrap;
}
.btn .arw {
  flex: none;
  transition: transform .4s var(--ease-out);
}
.btn:hover .arw { transform: translateX(5px); }

/* A shade darker than --signal so white label text clears AA (5.03:1, vs 4.42:1). */
.btn--primary { --btn-bg: #4A5DF5; --btn-bd: #4A5DF5; --btn-fg: #fff; }
.btn--primary:hover { --btn-bg: #4356F0; --btn-bd: #4356F0; }

.btn--dark:hover { --btn-bg: #000; --btn-bd: #000; }

.btn--ghost {
  --btn-bg: transparent;
  --btn-fg: var(--ink);
  --btn-bd: rgba(17,19,24,.24);
}
.btn--ghost:hover { --btn-bd: var(--carbon); --btn-bg: rgba(17,19,24,.04); }

.btn--on-dark {
  --btn-bg: var(--ivory);
  --btn-fg: var(--carbon);
  --btn-bd: var(--ivory);
}
.btn--on-dark:hover { --btn-bg: #fff; --btn-bd: #fff; }

.btn--ghost-dark {
  --btn-bg: transparent;
  --btn-fg: var(--ivory);
  --btn-bd: rgba(244,241,234,.28);
}
.btn--ghost-dark:hover { --btn-bd: rgba(244,241,234,.7); --btn-bg: rgba(244,241,234,.06); }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: .875rem;
  align-items: center;
}

/* Inline text link with arrow */
.link {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-weight: 500;
  color: var(--signal-ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .3s var(--ease);
}
.link .arw { transition: transform .4s var(--ease-out); }
.link:hover { border-color: currentColor; }
.link:hover .arw { transform: translateX(4px); }
.link--dark { color: var(--ivory); }

/* ==========================================================================
   06  HEADER / NAVIGATION
   ========================================================================== */

.header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background .45s var(--ease), border-color .45s var(--ease),
              backdrop-filter .45s var(--ease);
}
.header .wrap {
  display: flex;
  align-items: center;
  gap: 2rem;
  width: 100%;
}

/* Over the dark hero */
.header .brand,
.header .nav-link { color: var(--ivory); }
.header .nav-link::after { background: var(--ivory); }

/* Scrolled → warm-ivory surface with carbon typography.
   Opaque rather than translucent: over the carbon hero a semi-transparent
   ivory reads as muddy grey instead of a clean surface. */
.header.is-stuck {
  background: var(--ivory);
  border-bottom-color: var(--soft-grey);
}
.header.is-stuck .brand,
.header.is-stuck .nav-link { color: var(--carbon); }
.header.is-stuck .nav-link::after { background: var(--carbon); }
.header.is-stuck .btn--on-dark {
  --btn-bg: var(--carbon); --btn-fg: var(--ivory); --btn-bd: var(--carbon);
}
.header.is-stuck .btn--on-dark:hover { --btn-bg: var(--signal); --btn-bd: var(--signal); }
.header.is-stuck .burger span { background: var(--carbon); }

.brand {
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  text-decoration: none;
  flex: none;
  transition: color .45s var(--ease), opacity .3s var(--ease);
}
.brand:hover { opacity: .78; }
.brand-mark { width: 26px; height: 26px; flex: none; }
.brand-word {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1875rem;
  letter-spacing: -.005em;
  line-height: 1;
}

.nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: clamp(1.25rem, .4rem + 1.7vw, 2.25rem);
}
.nav-link {
  position: relative;
  font-size: .9375rem;
  font-weight: 450;
  text-decoration: none;
  letter-spacing: -.005em;
  padding: .35rem 0;
  transition: color .45s var(--ease), opacity .3s var(--ease);
  white-space: nowrap;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  height: 1px; width: 100%;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s var(--ease-out);
}
.nav-link:hover::after,
.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { opacity: 1; }

.header-cta {
  flex: none;
  margin-left: clamp(.5rem, 1.4vw, 1.5rem);
  padding: .7rem 1.125rem;   /* lighter than a page-level CTA */
  font-size: .875rem;
}

/* Burger */
.burger {
  display: none;
  margin-left: auto;
  width: 44px; height: 44px;
  flex-direction: column;   /* the three bars stack — without this they'd sit in a row */
  align-items: center;
  justify-content: center;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 0;
}
.burger span {
  display: block;
  width: 22px; height: 1.5px;
  background: var(--ivory);
  transition: transform .4s var(--ease-out), opacity .25s var(--ease), background .45s var(--ease);
}
.burger span + span { margin-top: 6px; }
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* Mobile drawer */
.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 99;
  background: var(--carbon);
  padding: calc(var(--header-h) + 2.5rem) var(--gutter) 3rem;
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity .4s var(--ease), transform .4s var(--ease), visibility .4s;
  overflow-y: auto;
}
.mobile-nav.is-open { opacity: 1; visibility: visible; transform: none; }
.mobile-nav a.m-link {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 1.2rem + 2.4vw, 2.5rem);
  font-weight: 500;
  letter-spacing: -.03em;
  color: var(--ivory);
  text-decoration: none;
  padding: .55rem 0;
  border-bottom: 1px solid var(--carbon-line);
  display: flex;
  align-items: baseline;
  gap: 1rem;
  transition: color .3s var(--ease);
}
.mobile-nav a.m-link:hover { color: var(--signal); }
.mobile-nav a.m-link .n {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .12em;
  color: var(--ink-inv-faint);
}
.mobile-nav .m-foot { margin-top: auto; padding-top: 2.5rem; }

/* ==========================================================================
   07  SECTIONS & SURFACES
   ========================================================================== */

.section {
  padding-block: var(--section-y);
  position: relative;
}
.section--lg   { padding-block: var(--section-y-lg); }
.section--tight{ padding-block: clamp(3.5rem, 2rem + 5vw, 6rem); }

.s-ivory  { background: var(--ivory); color: var(--ink); }
.s-raised { background: var(--ivory-raised); color: var(--ink); }
.s-sunken { background: var(--ivory-sunken); color: var(--ink); }
.s-carbon { background: var(--carbon); color: var(--ink-inv); }
.s-carbon-deep { background: var(--carbon-sunken); color: var(--ink-inv); }

/* Inverted text colours inside dark surfaces */
.s-carbon .lead, .s-carbon .muted,
.s-carbon-deep .lead, .s-carbon-deep .muted { color: var(--ink-inv-muted); }
.s-carbon .faint, .s-carbon-deep .faint { color: var(--ink-inv-faint); }
.s-carbon .label, .s-carbon-deep .label { color: var(--ink-inv-faint); }
/* .cta, .mega and .footer set a carbon background without the .s-carbon class,
   so they need naming here too — otherwise the eyebrow keeps the light-surface
   blue and drops to 2.9:1. */
.s-carbon .label--signal,
.s-carbon-deep .label--signal,
.cta .label--signal,
.page-hero .label--signal { color: var(--signal-on-dark); }
.s-carbon .rule, .s-carbon-deep .rule { background: var(--carbon-line); }
.s-carbon .link, .s-carbon-deep .link { color: var(--ivory); }

/* Blueprint grid backdrop for dark technical sections.
   No overflow:hidden — it would make this the scrollport for any
   position:sticky descendant. The ::before is inset:0 and cannot overflow. */
.blueprint { position: relative; }
.blueprint::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(244,241,234,.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(244,241,234,.045) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 30%, transparent 100%);
  mask-image: radial-gradient(ellipse 90% 70% at 50% 40%, #000 30%, transparent 100%);
  pointer-events: none;
}
.blueprint > * { position: relative; z-index: 1; }

/* Light architectural grid — see .blueprint on why there is no overflow:hidden */
.gridlines { position: relative; }
.gridlines::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(17,19,24,.05) 1px, transparent 1px);
  background-size: calc(100% / 12) 100%;
  -webkit-mask-image: linear-gradient(to bottom, transparent, #000 12%, #000 88%, transparent);
  mask-image: linear-gradient(to bottom, transparent, #000 12%, #000 88%, transparent);
  pointer-events: none;
}
.gridlines > * { position: relative; z-index: 1; }

/* ---- Page hero (inner pages) ---- */
.page-hero {
  padding-top: calc(var(--header-h) + clamp(4.5rem, 3rem + 7vw, 9rem));
  padding-bottom: clamp(4rem, 2.5rem + 6vw, 8rem);
  background: var(--carbon);
  color: var(--ink-inv);
  position: relative;
  overflow: hidden;
}
.page-hero .eyebrow {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--signal-on-dark);
  display: block;
  margin-bottom: 2rem;
}
.page-hero .lead { color: var(--ink-inv-muted); margin-top: 2rem; max-width: 60ch; }

/* Breadcrumb-ish page counter */
.page-meta {
  display: flex;
  gap: 1.25rem;
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--carbon-line);
  flex-wrap: wrap;
}
.page-meta span { display: inline-flex; align-items: center; gap: .5rem; }
.page-meta span::before {
  content: "";
  width: 5px; height: 5px;
  background: var(--signal);
  border-radius: 50%;
  flex: none;
}
.page-meta a {
  color: var(--ivory);
  text-decoration: none;
  border-bottom: 1px solid rgba(244,241,234,.35);
  transition: border-color .3s var(--ease);
}
.page-meta a:hover { border-bottom-color: var(--ivory); }

/* ==========================================================================
   08  CARDS & PRIMITIVES
   ========================================================================== */

.card {
  background: var(--ivory-raised);
  border: 1px solid var(--soft-grey);
  border-radius: var(--radius);
  padding: clamp(1.5rem, 1rem + 1.4vw, 2.25rem);
  transition: border-color .4s var(--ease), transform .4s var(--ease), background .4s var(--ease);
}
.card--dark {
  background: var(--carbon-raised);
  border-color: var(--carbon-line);
  color: var(--ink-inv);
}
.card--dark .muted { color: var(--ink-inv-muted); }
.card--hover:hover { border-color: var(--signal-line); transform: translateY(-3px); }
.card--flat { background: transparent; }

.card h3, .card .t-h3 { margin-bottom: .75rem; }
.card p { color: var(--ink-muted); font-size: 1rem; line-height: 1.6; }
.card--dark p { color: var(--ink-inv-muted); }

/* Numbered card with hairline top rule */
.card--numbered { padding-top: 1.5rem; border-top: 2px solid var(--carbon); border-radius: 0; background: transparent; border-left: 0; border-right: 0; border-bottom: 0; }
.card--numbered .n {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  color: var(--signal-ink);
  display: block;
  margin-bottom: 1.25rem;
}

/* Auto-fitting card grids */
.cards {
  display: grid;
  gap: clamp(1rem, .6rem + 1.2vw, 1.75rem);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
}
.cards--2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr)); }
.cards--3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }
/* Four cards with real paragraphs in them — 2x2 rather than an orphaned fourth. */
.cards--wide { grid-template-columns: repeat(auto-fit, minmax(min(100%, 420px), 1fr)); }
.cards--4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 230px), 1fr)); }

/* Pill / chip list */
.chips { display: flex; flex-wrap: wrap; gap: .5rem; padding: 0; margin: 0; list-style: none; }
.chip {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  padding: .45rem .7rem;
  border: 1px solid var(--soft-grey);
  border-radius: var(--radius-sm);
  color: var(--ink-muted);
  background: var(--ivory-raised);
  white-space: nowrap;
}
.chip--dark { border-color: var(--carbon-line); background: rgba(244,241,234,.03); color: var(--ink-inv-muted); }
.chip--signal { border-color: var(--signal-line); color: var(--signal-ink); background: var(--signal-soft); }

/* Dot-separated capability line */
.dotline {
  font-size: 1rem;
  color: var(--ink-muted);
  line-height: 1.8;
}
.dotline b { font-weight: 400; color: var(--ink); }

/* Big pull statement */
.statement {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--t-h2);
  line-height: 1.1;
  letter-spacing: -.028em;
  text-wrap: balance;
}

/* Callout band — the "principle" blocks in the brief */
.principle {
  border-left: 2px solid var(--signal);
  padding: .25rem 0 .25rem clamp(1.25rem, .8rem + 1.4vw, 2rem);
}
.principle .label { margin-bottom: 1rem; }
.principle p {
  font-family: var(--font-display);
  font-size: var(--t-h3);
  line-height: 1.28;
  letter-spacing: -.02em;
  font-weight: 500;
}

/* Two-column list of "outgrown / don't need" */
.contrast-cols {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr));
  gap: clamp(1.5rem, 1rem + 3vw, 4rem);
}
.contrast-list { list-style: none; margin: 1.5rem 0 0; padding: 0; }
.contrast-list li {
  padding: .95rem 0;
  border-bottom: 1px solid var(--carbon-line);
  display: flex;
  gap: .875rem;
  align-items: baseline;
  font-size: 1.0625rem;
}
.contrast-list li::before {
  content: "";
  flex: none;
  width: 14px; height: 1px;
  background: var(--ink-inv-faint);
  transform: translateY(-4px);
}
.contrast-list--ok li::before { background: var(--signal); }

/* Definition rows (outcomes, principles) */
.rows { border-top: 1px solid var(--soft-grey); }
.rows > div {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(1rem, .5rem + 2vw, 3rem);
  padding: clamp(1.5rem, 1rem + 1.4vw, 2.25rem) 0;
  border-bottom: 1px solid var(--soft-grey);
  align-items: start;
}
.rows--dark { border-top-color: var(--carbon-line); }
.rows--dark > div { border-bottom-color: var(--carbon-line); }
.rows h3 { font-size: var(--t-h3); }
.rows p { color: var(--ink-muted); margin: 0; }
.rows--dark p { color: var(--ink-inv-muted); }

/* ==========================================================================
   09  DIAGRAMS
   ========================================================================== */

.figure {
  position: relative;
  width: 100%;
}
.figure svg { width: 100%; height: auto; overflow: visible; }
.figure-cap {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 1.25rem;
  display: flex;
  gap: .625rem;
  align-items: center;
}
.figure-cap::before {
  content: "";
  width: 6px; height: 6px;
  border: 1px solid currentColor;
  transform: rotate(45deg);
  flex: none;
}

/* --- shared SVG primitives --- */
.d-node       { fill: var(--carbon-raised); stroke: var(--carbon-line-2); stroke-width: 1; }
.d-node-light { fill: var(--ivory-raised);  stroke: var(--soft-grey);     stroke-width: 1; }
.d-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  text-transform: uppercase;
  fill: var(--ink-inv-muted);
}
.d-label-light { fill: var(--ink-muted); }
.d-title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 14px;
  letter-spacing: -.01em;
  fill: var(--ivory);
}
.d-title-light { fill: var(--carbon); }
.d-link  { fill: none; stroke: var(--signal); stroke-width: 1.25; opacity: .55; }
.d-link-faint { fill: none; stroke: var(--carbon-line-2); stroke-width: 1; }
.d-arc   { fill: none; stroke: var(--signal); stroke-width: 1; opacity: .35; }
.d-dash  { fill: none; stroke: #B9BDC8; stroke-width: 1; stroke-dasharray: 3 5; }

/* Line-drawing animation driver */
.draw {
  stroke-dasharray: var(--len, 1000);
  stroke-dashoffset: var(--len, 1000);
}
.in-view .draw {
  animation: draw-in 1.5s var(--ease-out) forwards;
  animation-delay: var(--delay, 0s);
}
@keyframes draw-in { to { stroke-dashoffset: 0; } }

/* Node pop-in */
.pop { opacity: 0; transform: scale(.92); transform-origin: center; transform-box: fill-box; }
.in-view .pop {
  animation: pop-in .7s var(--ease-out) forwards;
  animation-delay: var(--delay, 0s);
}
@keyframes pop-in { to { opacity: 1; transform: scale(1); } }

/* Travelling signal — a short dash running the length of a path.
   Length is measured by site.js and written into --len.               */
.flow {
  fill: none;
  stroke: var(--signal);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-dasharray: 5 var(--len, 1000);
  stroke-dashoffset: 0;
  opacity: 0;
}
.in-view .flow {
  opacity: 1;
  animation: flow var(--flow-dur, 3.4s) linear infinite;
  animation-delay: var(--delay, 1.2s);
}
@keyframes flow {
  from { stroke-dashoffset: 0; }
  to   { stroke-dashoffset: calc(var(--len, 1000) * -1); }
}

/* --- Fragmented stack (left panel of the ecosystem comparison) --- */
.fragment-panel {
  position: relative;
  padding: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  border: 1px solid var(--soft-grey);
  border-radius: var(--radius);
  background: var(--ivory-sunken);
  min-height: 420px;
  flex: 1;
  display: flex;
  align-items: center;
}
.fragment-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  column-gap: .75rem;
  row-gap: clamp(1.5rem, .5rem + 3vw, 3.25rem);
  position: relative;
  z-index: 2;
  width: 100%;
}
.frag {
  border: 1px solid #D6D8DE;
  background: #FFF;
  border-radius: var(--radius-sm);
  padding: .875rem .75rem;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: #6E7482;            /* 4.68:1 on the tile's white — these are content labels */
  text-align: center;
  line-height: 1.3;
  opacity: 0;
  transform: translateY(10px) rotate(var(--rot, 0deg));
  transition: opacity .5s var(--ease-out), transform .6s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.in-view .frag { opacity: 1; transform: translateY(0) rotate(var(--rot, 0deg)); }
.fragment-panel .tangle {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

/* Ordered architecture (right panel) */
.order-panel {
  position: relative;
  padding: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius);
  background: var(--carbon);
  min-height: 420px;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* --- Architecture layers (blueprint stack) --- */
.layers { display: grid; gap: 0; }
.layer {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 3.2fr) minmax(0, 8.8fr);
  gap: clamp(1rem, .5rem + 2vw, 3rem);
  align-items: center;
  padding: clamp(1.5rem, 1rem + 1.6vw, 2.5rem) clamp(1.25rem, .8rem + 1.4vw, 2.25rem);
  border: 1px solid var(--carbon-line);
  background: rgba(244,241,234,.022);
  transition: background .45s var(--ease), border-color .45s var(--ease);
}
.layer + .layer { border-top: 0; }
.layer:first-child { border-radius: var(--radius) var(--radius) 0 0; }
.layer:last-child  { border-radius: 0 0 var(--radius) var(--radius); }
.layer:hover { background: rgba(83,103,255,.06); border-color: var(--signal-line); }
.layer-name {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ivory);
  display: flex;
  align-items: center;
  gap: .875rem;
}
.layer-name .idx { color: var(--signal-on-dark); font-size: .6875rem; }
.layer-items { color: var(--ink-inv-muted); font-size: 1rem; line-height: 1.7; }
.layer-items b { font-weight: 400; color: var(--ivory); }

/* Connective stitches between layers */
.layer-stitch {
  height: 26px;
  position: relative;
  display: flex;
  justify-content: space-evenly;
  align-items: stretch;
  margin: 0;
}
.layer-stitch i {
  display: block;
  width: 1px;
  background: linear-gradient(to bottom, var(--signal-line), rgba(83,103,255,.08));
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .6s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.in-view .layer-stitch i { transform: scaleY(1); }

/* --- AI query demo --- */
.ai-demo {
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius);
  background: var(--carbon-raised);
  overflow: hidden;
}
.ai-demo + .ai-demo { margin-top: clamp(1rem, .6rem + 1.2vw, 1.75rem); }
.ai-ask {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  padding: clamp(1.25rem, 1rem + 1vw, 1.75rem);
  border-bottom: 1px solid var(--carbon-line);
}
.ai-ask .label { flex: none; padding-top: .35rem; }
.ai-ask q {
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, .95rem + .7vw, 1.5rem);
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -.02em;
  color: var(--ivory);
  quotes: "“" "”";
}
.ai-track {
  display: flex;
  align-items: center;
  gap: 0;
  padding: clamp(1.25rem, 1rem + 1vw, 1.75rem);
  flex-wrap: wrap;
  row-gap: 1rem;
}
.ai-stop {
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius-sm);
  padding: .55rem .75rem;
  white-space: nowrap;
  transition: color .35s var(--ease), border-color .35s var(--ease), background .35s var(--ease);
}
.ai-stop.is-lit {
  color: var(--ivory);
  border-color: var(--signal);
  background: rgba(83,103,255,.12);
}
.ai-wire {
  flex: 1 1 24px;
  min-width: 24px;
  height: 1px;
  background: var(--carbon-line);
  position: relative;
  overflow: hidden;
}
.ai-wire::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .45s linear;
}
.ai-wire.is-lit::after { transform: scaleX(1); }
.ai-result {
  padding: clamp(1.25rem, 1rem + 1vw, 1.75rem);
  border-top: 1px solid var(--carbon-line);
  background: rgba(83,103,255,.05);
  display: flex;
  gap: 1rem;
  align-items: baseline;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity .55s var(--ease), transform .55s var(--ease-out);
}
.ai-result.is-shown { opacity: 1; transform: none; }
.ai-result strong {
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, .95rem + .6vw, 1.375rem);
  font-weight: 500;
  letter-spacing: -.02em;
  color: var(--ivory);
}
.ai-replay {
  background: none;
  border: 0;
  color: var(--signal-on-dark);
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  cursor: pointer;
  padding: .5rem;
  margin-left: auto;
  flex: none;
  align-self: center;
}
.ai-replay:hover { text-decoration: underline; }

/* --- Process steps --- */
.steps { counter-reset: step; }
.step {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr);
  gap: clamp(1rem, .5rem + 2.5vw, 4rem);
  padding: clamp(2rem, 1.2rem + 2.4vw, 3.5rem) 0;
  border-top: 1px solid var(--soft-grey);
  position: relative;
}
.step:last-child { border-bottom: 1px solid var(--soft-grey); }
.step-n {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  color: var(--signal-ink);
  margin-bottom: 1rem;
  display: block;
}
.step h3 { font-size: var(--t-h3); }
.step .step-body p { color: var(--ink-muted); }
.step .chips { margin-top: 1.5rem; }

/* --- Ecosystem satellite diagram wrapper --- */
.eco {
  position: relative;
  display: grid;
  place-items: center;
  padding: clamp(1rem, .5rem + 2vw, 2rem) 0;
}

/* Small connection tick used on mobile cards */
.tether {
  display: flex;
  align-items: center;
  gap: .625rem;
  font-family: var(--font-mono);
  font-size: .625rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--signal-ink);
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--signal-line);
}
.tether::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 4px var(--signal-soft);
  flex: none;
}

/* --- Platform family cards --- */
.family { display: grid; gap: 1px; background: var(--soft-grey); border: 1px solid var(--soft-grey); border-radius: var(--radius); overflow: hidden; }
.fam {
  background: var(--ivory-raised);
  padding: clamp(1.5rem, 1rem + 1.6vw, 2.5rem);
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: clamp(1rem, .5rem + 2vw, 3rem);
  align-items: start;
  transition: background .4s var(--ease);
  position: relative;
}
.fam:hover { background: #fff; }
.fam::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 2px;
  background: var(--signal);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .5s var(--ease-out);
}
.fam:hover::before { transform: scaleY(1); }
.fam-key .t-h3 { margin-bottom: .5rem; }
.fam-key .k {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--signal-ink);
  display: block;
  margin-bottom: .75rem;
}
.fam-key p { color: var(--ink-muted); font-size: 1.0625rem; }

/* --- Outcome grid --- */
.outcomes { display: grid; gap: 1px; background: var(--carbon); border: 1px solid var(--carbon-line); border-radius: var(--radius); overflow: hidden; grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr)); }
.outcome {
  background: var(--carbon);
  box-shadow: 0 0 0 1px var(--carbon-line);
  padding: clamp(1.75rem, 1.2rem + 1.6vw, 2.5rem);
  transition: background .4s var(--ease);
}
.outcome:hover { background: var(--carbon-raised); }
.outcome .n {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  color: var(--signal-on-dark);
  display: block;
  margin-bottom: 1.5rem;
}
.outcome h3 { font-size: 1.375rem; margin-bottom: .625rem; color: var(--ivory); }
.outcome p { color: var(--ink-inv-muted); font-size: 1rem; margin: 0; }

/* --- Full-screen statement --- */
.mega {
  min-height: 92vh;
  display: grid;
  place-items: center;
  text-align: center;
  background: var(--carbon);
  color: var(--ivory);
  padding-block: var(--section-y);
}
.mega h2 {
  font-size: clamp(2.5rem, 1.1rem + 6vw, 6.25rem);
  line-height: .98;
  letter-spacing: -.045em;
  font-weight: 500;
}
.mega .sub {
  font-size: var(--t-lead);
  color: var(--ink-inv-muted);
  margin-top: 2.5rem;
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .9s var(--ease) .35s, transform .9s var(--ease-out) .35s;
}
.mega .mark {
  margin-top: 3.5rem;
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .9s var(--ease) .6s, transform .9s var(--ease-out) .6s;
}
.mega.in-view .sub, .mega.in-view .mark { opacity: 1; transform: none; }

/* --- Final CTA --- */
.cta {
  background: var(--carbon);
  color: var(--ivory);
  padding-block: var(--section-y-lg);
  position: relative;
  overflow: hidden;
}
.cta h2 { font-size: var(--t-h1); max-width: 20ch; }
.cta .lets { color: var(--signal); }
.cta .btn-row { margin-top: 3rem; }
.cta-note {
  margin-top: 2.5rem;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
}

/* ==========================================================================
   10  MOTION / REVEAL
   ========================================================================== */

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity .85s var(--ease), transform .85s var(--ease-out);
  transition-delay: var(--delay, 0s);
  will-change: opacity, transform;
}
.reveal.in-view { opacity: 1; transform: none; }

.reveal-l { opacity: 0; transform: translateX(-24px); transition: opacity .85s var(--ease), transform .85s var(--ease-out); transition-delay: var(--delay, 0s); }
.reveal-r { opacity: 0; transform: translateX(24px);  transition: opacity .85s var(--ease), transform .85s var(--ease-out); transition-delay: var(--delay, 0s); }
.reveal-l.in-view, .reveal-r.in-view { opacity: 1; transform: none; }

/* Line that draws itself horizontally */
.rule-draw { transform: scaleX(0); transform-origin: left; transition: transform 1.1s var(--ease-out); transition-delay: var(--delay, 0s); }
.rule-draw.in-view { transform: scaleX(1); }

/* Words that stagger up (hero headline).
   The mask needs headroom for descenders, hence the padding/margin pair. */
.rise {
  display: block;
  overflow: hidden;
  padding-bottom: .14em;
  margin-bottom: -.14em;
}
.rise > span {
  display: block;
  transform: translateY(105%);
  transition: transform 1.05s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.is-ready .rise > span { transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal, .reveal-l, .reveal-r { opacity: 1; transform: none; }
  .rise > span { transform: none; }
  .draw { stroke-dashoffset: 0; }
  .flow { display: none; }
  .pop { opacity: 1; transform: none; }
  .frag { opacity: 1; transform: none; }
  .rule-draw { transform: none; }
  .layer-stitch i { transform: scaleY(1); }
  .mega .sub, .mega .mark { opacity: 1; transform: none; }
}

/* ==========================================================================
   11  FORMS
   ========================================================================== */

.form { display: grid; gap: 1.5rem; }
.field { display: grid; gap: .6rem; }
.field label {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.field .req { color: var(--signal-ink); }
.field input,
.field select,
.field textarea {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  color: var(--ink);
  background: var(--ivory-raised);
  border: 1px solid var(--soft-grey);
  border-radius: var(--radius-sm);
  padding: .9rem 1rem;
  width: 100%;
  transition: border-color .3s var(--ease), background .3s var(--ease);
  appearance: none;
}
.field select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1.5 6 6.5 11 1.5' fill='none' stroke='%235C6272' stroke-width='1.4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}
.field textarea { min-height: 150px; resize: vertical; line-height: 1.6; }
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--signal);
  background: #fff;
  outline: none;
}
.field input::placeholder, .field textarea::placeholder { color: var(--ink-faint); }
.field-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); gap: 1.5rem; }

.form-note {
  font-size: .9375rem;
  color: var(--ink-muted);
  line-height: 1.6;
}
.form-status {
  padding: 1rem 1.125rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--signal-line);
  background: var(--signal-soft);
  font-size: 1rem;
  display: none;
}
.form-status.is-shown { display: block; }
.form-status.is-error { border-color: #E0B4B4; background: #FBEFEF; }

/* ==========================================================================
   12  FOOTER
   ========================================================================== */

.footer {
  background: var(--carbon-sunken);
  color: var(--ink-inv);
  padding-block: clamp(3.5rem, 2rem + 4vw, 5.5rem) 2.5rem;
}
.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(2rem, 1rem + 4vw, 5rem);
  padding-bottom: clamp(2.5rem, 1.5rem + 3vw, 4rem);
  border-bottom: 1px solid var(--carbon-line);
}
.footer .brand-word { font-size: 1.375rem; }
.footer-tag {
  color: var(--ink-inv-muted);
  margin-top: 1.25rem;
  font-size: 1.0625rem;
  max-width: 34ch;
}
.footer-nav {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 150px), 1fr));
  gap: 2rem;
}
.footer-nav h4 {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
  font-weight: 500;
  margin-bottom: 1.125rem;
}
.footer-nav ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .625rem; }
.footer-nav a {
  color: var(--ink-inv-muted);
  text-decoration: none;
  font-size: .9375rem;
  transition: color .3s var(--ease);
}
.footer-nav a:hover { color: var(--ivory); }
.footer-bottom {
  padding-top: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
}
.footer-bottom a { color: inherit; text-decoration: none; }
.footer-bottom a:hover { color: var(--ivory); }
.footer-bottom .set { display: flex; gap: 1.5rem; flex-wrap: wrap; }

/* ==========================================================================
   13  RESPONSIVE
   ========================================================================== */

@media (max-width: 1040px) {
  .nav { display: none; }
  .header-cta { display: none; }
  .burger { display: flex; }
  /* minmax(0, 1fr), not 1fr — a wide child must never force the track open */
  .split, .split--sticky { grid-template-columns: minmax(0, 1fr); }
  .split--sticky > :first-child { position: static; }
  .fam { grid-template-columns: 1fr; }
  .step { grid-template-columns: 1fr; }
  .rows > div { grid-template-columns: 1fr; gap: .75rem; }
  .footer-top { grid-template-columns: 1fr; }
  .layer { grid-template-columns: 1fr; gap: 1rem; align-items: start; }
}

@media (max-width: 720px) {
  :root { --header-h: 66px; }
  .fragment-grid { grid-template-columns: repeat(2, 1fr); }
  .contrast-cols { gap: 2.5rem; }
  .mega { min-height: 76vh; }
  .btn { width: 100%; justify-content: space-between; }
  .btn-row { flex-direction: column; align-items: stretch; }
  .header .btn { width: auto; }
  .figure-cap { font-size: .6875rem; }
}

/* Desktop-only / mobile-only diagram switching */
.only-wide { display: block; }
.only-narrow { display: none; }
@media (max-width: 860px) {
  .only-wide { display: none; }
  .only-narrow { display: block; }
}

@media print {
  .header, .mobile-nav, .cta, .footer { display: none; }
  body { background: #fff; }
  .reveal, .reveal-l, .reveal-r { opacity: 1; transform: none; }
}

/* ==========================================================================
   14  PAGE MODULES
   ========================================================================== */

/* ---- Homepage hero ---- */

.hero {
  background: var(--carbon);
  color: var(--ink-inv);
  padding-top: calc(var(--header-h) + clamp(3.5rem, 2rem + 6vw, 7.5rem));
  padding-bottom: clamp(3rem, 2rem + 4vw, 5.5rem);
  position: relative;
  overflow: hidden;
}
.hero::after {
  /* a very quiet field of light behind the architecture */
  content: "";
  position: absolute;
  left: 50%; bottom: -20%;
  width: min(1100px, 120%); aspect-ratio: 2 / 1;
  transform: translateX(-50%);
  background: radial-gradient(ellipse at center, rgba(83,103,255,.14), transparent 62%);
  pointer-events: none;
}
.hero > * { position: relative; z-index: 1; }

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--signal-on-dark);
  margin: 0 0 clamp(1.75rem, 1rem + 2vw, 3rem);
  opacity: 0;
  transition: opacity .8s var(--ease);
}
.is-ready .hero-eyebrow { opacity: 1; }

.hero h1 { max-width: 18ch; }
.hero h1 .dim { color: var(--ink-inv-muted); }

.hero-cols {
  display: grid;
  grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
  gap: clamp(1.75rem, 1rem + 3vw, 4rem);
  align-items: end;
  margin-top: clamp(2.25rem, 1.5rem + 2.5vw, 3.75rem);
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .9s var(--ease) .45s, transform .9s var(--ease-out) .45s;
}
.is-ready .hero-cols { opacity: 1; transform: none; }
.hero-cols .lead { color: var(--ink-inv-muted); max-width: 52ch; margin: 0; }

.hero-figure {
  margin-top: clamp(2.5rem, 1.5rem + 4vw, 5rem);
  opacity: 0;
  transition: opacity 1s var(--ease) .7s;
}
.is-ready .hero-figure { opacity: 1; }
.hero-figure svg { width: 100%; height: auto; overflow: visible; }

.hero-caption {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-inv-muted);
  text-align: center;
  margin: clamp(1.5rem, 1rem + 1.5vw, 2.25rem) 0 0;
}
.hero-caption b { color: var(--signal-on-dark); font-weight: 500; }

.hero-strip {
  margin-top: clamp(2.5rem, 1.5rem + 3vw, 4.5rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--carbon-line);
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.5rem;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
}
.hero-strip span { display: inline-flex; align-items: center; gap: 1.5rem; }
.hero-strip span::after { content: "·"; opacity: .45; }
.hero-strip span:last-child::after { content: ""; }

@media (max-width: 900px) {
  .hero-cols { grid-template-columns: 1fr; align-items: start; }
}

/* ---- Fragmented stack overlay (messy connections) ---- */
.tangle path { stroke: #C2C6CF; stroke-width: 1; fill: none; stroke-dasharray: 4 6; }
.tangle .x { stroke: #CDD1D9; }

.frag-legend {
  margin-top: 1.5rem;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.compare {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 340px), 1fr));
  gap: clamp(1.25rem, .8rem + 2vw, 2.5rem);
  align-items: stretch;
}
.compare-side { display: flex; flex-direction: column; }
/* Captions sit directly under their panel; panels flex to equal height so the
   two sides of the comparison stay aligned. */
.compare-side > .panel-cap { margin-top: 1.5rem; }
.compare-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}
.compare-head h3 { font-size: var(--t-h4); }
.compare-head .tag {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-faint);
}
.compare-side--good .compare-head .tag { color: var(--signal-ink); }
.order-panel .figure-cap { color: var(--ink-inv-faint); }

/* Caption strips beneath each comparison panel */
.panel-cap {
  margin-top: 1.25rem;
  font-family: var(--font-display);
  font-size: var(--t-h4);
  font-weight: 500;
  letter-spacing: -.015em;
}
.panel-cap + p { margin-top: .5rem; color: var(--ink-muted); font-size: 1rem; }

/* ---- Example ecosystem hub ---- */
.hub-cards {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: clamp(.75rem, .4rem + 1vw, 1.25rem);
}
.hub-card {
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius);
  background: var(--carbon-raised);
  padding: clamp(1.125rem, .8rem + 1vw, 1.625rem);
  transition: border-color .4s var(--ease), background .4s var(--ease);
}
.hub-card:hover { border-color: var(--signal-line); background: #1C2029; }
.hub-card .k {
  font-family: var(--font-mono);
  font-size: .625rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--signal-on-dark);
  display: block;
  margin-bottom: .875rem;
}
.hub-card h3 { font-size: 1.0625rem; color: var(--ivory); margin-bottom: .5rem; line-height: 1.25; }
.hub-card p { font-size: .875rem; color: var(--ink-inv-muted); margin: 0; line-height: 1.55; }

.core-link { position: relative; height: 64px; }
.core-drops {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  height: 63px;
}
.core-drops i {
  display: block;
  width: 1px;
  height: 100%;
  justify-self: center;
  background: linear-gradient(to bottom, rgba(83,103,255,.15), var(--signal));
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .7s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.in-view .core-drops i { transform: scaleY(1); }
.core-rail {
  height: 1px;
  background: var(--signal);
  opacity: .55;
  transform: scaleX(0);
  transition: transform 1.1s var(--ease-out) .5s;
}
.in-view .core-rail { transform: scaleX(1); }

.core-bar {
  border: 1px solid var(--signal-line);
  border-radius: var(--radius);
  background: rgba(83,103,255,.07);
  padding: clamp(1.5rem, 1rem + 1.4vw, 2.25rem);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem clamp(1.5rem, 1rem + 2vw, 3rem);
  justify-content: space-between;
}
.core-bar .core-title {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--ivory);
}
.core-bar .core-items {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-inv-muted);
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1.25rem;
}

@media (max-width: 980px) {
  .hub-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .core-link { display: none; }
  .core-bar { margin-top: 1.25rem; }
  .hub-card { position: relative; }
}
@media (max-width: 560px) {
  .hub-cards { grid-template-columns: 1fr; }
}

/* ---- Case study (Work page) ---- */
.case {
  border: 1px solid var(--soft-grey);
  border-radius: var(--radius-lg);
  background: var(--ivory-raised);
  overflow: hidden;
}
.case + .case { margin-top: clamp(2rem, 1.2rem + 2.4vw, 3.5rem); }
.case-head {
  padding: clamp(1.75rem, 1.2rem + 1.8vw, 2.75rem);
  border-bottom: 1px solid var(--soft-grey);
  background: var(--carbon);
  color: var(--ivory);
}
.case-head .sector {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--signal-on-dark);
  display: block;
  margin-bottom: 1.25rem;
}
.case-head h2 { font-size: var(--t-h3); max-width: 44ch; }
.case-head .chips { margin-top: 1.75rem; }
.case-body { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); gap: 1px; background: var(--ivory-raised); }
.case-cell { background: var(--ivory-raised); box-shadow: 0 0 0 1px var(--soft-grey); padding: clamp(1.5rem, 1rem + 1.4vw, 2.25rem); }
.case-cell h3 {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 1rem;
}
.case-cell p { font-size: 1rem; color: var(--ink-muted); margin: 0; }
.case-cell ul { margin: 0; padding-left: 1.1rem; color: var(--ink-muted); font-size: 1rem; }
.case-cell ul li + li { margin-top: .4rem; }
/* The outcome is the punchline — give it the full width of the last row. */
.case-cell--outcome { background: var(--carbon); grid-column: 1 / -1; }
.case-cell--outcome p { max-width: 90ch; }
.case-cell--outcome h3 { color: var(--signal-on-dark); }
.case-cell--outcome p, .case-cell--outcome ul { color: var(--ink-inv-muted); }
.case-cell--outcome strong { color: var(--ivory); font-weight: 500; }

/* ---- Artefact frames (How It Works) ---- */
.artefact {
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius);
  background: var(--carbon-sunken);
  overflow: hidden;
}
.artefact-bar {
  display: flex;
  align-items: center;
  gap: .625rem;
  padding: .75rem 1rem;
  border-bottom: 1px solid var(--carbon-line);
  font-family: var(--font-mono);
  font-size: .625rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-inv-faint);
}
.artefact-bar::before {
  content: "";
  width: 6px; height: 6px;
  border: 1px solid var(--signal);
  transform: rotate(45deg);
  flex: none;
}
.artefact-body { padding: clamp(1.25rem, 1rem + 1vw, 1.75rem); }

/* Process-map artefact rows */
.pmap { display: grid; gap: .5rem; }
.pmap-row {
  display: grid;
  /* Every track is minmax(0, …): a fixed first track plus a nowrap `auto`
     track would otherwise give the row a ~400px min-content width, which
     propagates up the split and clips body copy off-screen on phones. */
  grid-template-columns: minmax(0, 96px) minmax(0, 1fr) minmax(0, auto);
  gap: .875rem;
  align-items: center;
  font-family: var(--font-mono);
  font-size: .6875rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--ink-inv-muted);
}
.pmap-row .who { color: var(--ink-inv-faint); }
.pmap-bar {
  height: 22px;
  border-radius: 3px;
  background: rgba(83,103,255,.16);
  border: 1px solid var(--signal-line);
  position: relative;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .8s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.in-view .pmap-bar { transform: scaleX(1); }
.pmap-row.is-friction .pmap-bar { background: rgba(224,140,140,.14); border-color: rgba(224,140,140,.4); }
.pmap-row .t { color: var(--ink-inv-faint); white-space: nowrap; }

/* On phones the row has nowhere near the width for actor + bar + label on one
   line, so drop the label to its own line and let it wrap. */
@media (max-width: 720px) {
  .pmap-row {
    grid-template-columns: minmax(0, 84px) minmax(0, 1fr);
    row-gap: .3rem;
    margin-bottom: .35rem;
  }
  .pmap-row .t {
    grid-column: 1 / -1;
    white-space: normal;
    line-height: 1.5;
  }
}

/* ---- Contact page ---- */
.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(2rem, 1rem + 4vw, 5rem);
  align-items: start;
}
@media (max-width: 900px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-aside .rows > div { grid-template-columns: 1fr; gap: .5rem; }
.contact-aside .rows h3 { font-size: 1.125rem; }

/* ---- Long-form prose (the engineering note) ---- */
.prose {
  max-width: 68ch;
  font-size: clamp(1.0625rem, 1rem + .3vw, 1.1875rem);
  line-height: 1.72;
  color: var(--ink);
}
/* Both rules are (0,1,0) so the adjacent-sibling one wins on order. Do NOT write
   this reset as `.prose p` — at (0,1,1) it outranks the spacing rule and every
   paragraph gap silently collapses to zero. */
.prose > * { margin: 0; }
.prose > * + * { margin-top: 1.5em; }
.prose h2 {
  font-size: var(--t-h3);
  letter-spacing: -.02em;
  margin-top: 2.6em;
  margin-bottom: -.4em;
}
.prose h2 + p { margin-top: 1.1em; }
.prose strong { font-weight: 500; color: var(--ink); }
.prose em { font-style: italic; }
.prose ul, .prose ol { margin-left: 0; padding-left: 1.35em; color: var(--ink-muted); }
.prose li + li { margin-top: .5em; }
.prose a { color: var(--signal-ink); text-decoration: none; border-bottom: 1px solid var(--signal-line); }
.prose a:hover { border-bottom-color: var(--signal-ink); }
.prose blockquote {
  margin: 2em 0;
  padding-left: clamp(1.25rem, .8rem + 1.4vw, 2rem);
  border-left: 2px solid var(--signal);
  font-family: var(--font-display);
  font-size: var(--t-h4);
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: -.015em;
  color: var(--ink);
}
.prose code {
  font-family: var(--font-mono);
  font-size: .875em;
  background: var(--ivory-sunken);
  border: 1px solid var(--soft-grey);
  border-radius: 4px;
  padding: .1em .35em;
}
/* A rule that reads as a section break rather than a divider */
.prose hr {
  border: 0;
  margin: 2.8em 0;
  height: 1px;
  background: var(--soft-grey);
  max-width: 5rem;
}

.note-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem 1.5rem;
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding-bottom: 2rem;
  margin-bottom: 2.75rem;
  border-bottom: 1px solid var(--soft-grey);
}

/* The one drawn idea in the note */
.note-figure {
  margin: clamp(2rem, 1.4rem + 2vw, 3.25rem) 0;
  max-width: 100%;
}
.note-figure .frame {
  border: 1px solid var(--carbon-line);
  border-radius: var(--radius);
  background: var(--carbon-sunken);
  padding: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  overflow-x: auto;
}
.note-figure svg { width: 100%; height: auto; min-width: 460px; }
.note-figure figcaption {
  font-family: var(--font-mono);
  font-size: var(--t-label);
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 1.125rem;
  display: flex;
  gap: .625rem;
  align-items: baseline;
}
.note-figure .scroll-hint { display: none; }
/* The diagram is wider than a phone; it scrolls inside its own frame, so say so. */
@media (max-width: 720px) {
  .note-figure .scroll-hint { display: inline; color: var(--signal-ink); }
}
.note-figure figcaption::before {
  content: "";
  width: 6px; height: 6px;
  border: 1px solid currentColor;
  transform: rotate(45deg);
  flex: none;
  position: relative;
  top: .45em;
}

/* ---- Named anchor offset helper ---- */
.anchor { scroll-margin-top: calc(var(--header-h) + 32px); }