/* ==========================================================================
   NebularHub — marketing site
   Tokens and rules follow brand/creative-brief.md (v1):
   §4 colour, §5 typography, §6 motion.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Tokens
   -------------------------------------------------------------------------- */
:root {
  /* Marketing palette — creative-brief §4 */
  --bg:            #0b0f14;   /* "control room at 2am" */
  --surface:       #121821;
  --surface-2:     #161e2a;
  --line:          #1f2937;
  --line-strong:   #2b384a;
  --text:          #e6edf6;   /* ~15:1 on --bg */
  --muted:         #93a4bc;   /* ~7:1 on --bg  */
  --azure:         #4da3ff;
  --violet:        #8b5cf6;
  --nebula:        linear-gradient(100deg, var(--azure), var(--violet));

  /* Type — creative-brief §5 */
  --font-display: 'Space Grotesk', 'Segoe UI', system-ui, sans-serif;
  --font-body:    'Inter', 'IBM Plex Sans Arabic', 'Segoe UI', system-ui, sans-serif;

  /* Layout */
  --wrap:    1180px;
  --gutter:  28px;

  /* Spacing scale */
  --s-1: 6px;   --s-2: 10px;  --s-3: 14px;  --s-4: 18px;
  --s-5: 24px;  --s-6: 32px;  --s-7: 44px;  --s-8: 56px;
  --s-9: 72px;  --s-10: 96px;

  /* Type ramp - 8 steps, ~1.07 ratio. Every size on the page is one of these. */
  --fs-2xs:  0.75rem;
  --fs-xs:   0.8rem;
  --fs-sm:   0.86rem;
  --fs-md:   0.92rem;
  --fs-base: 1rem;
  --fs-lg:   1.08rem;
  --fs-xl:   1.16rem;
  --fs-2xl:  1.34rem;

  /* Fluid display sizes */
  --fs-display:   clamp(2.4rem, 6vw, 4.4rem);
  --fs-headline:  clamp(1.7rem, 3.4vw, 2.5rem);
  --fs-statement: clamp(1.3rem, 2.6vw, 1.85rem);

  /* Radius scale - 6 / 10 / 14 / 18, plus pill. Circles use 50% (semantic). */
  --r-xs:   6px;
  --r-sm:   10px;
  --r-md:   14px;
  --r-lg:   18px;
  --r-pill: 999px;

  /* Neutral elevation. Every shadow carries an offset and a soft blur —
     no zero-offset chromatic halos. */
  --shadow-1: 0 6px 18px rgba(0, 0, 0, 0.30);
  --shadow-2: 0 12px 34px rgba(0, 0, 0, 0.38);
  --shadow-3: 0 20px 50px rgba(0, 0, 0, 0.45);

  /* Motion — creative-brief §6: reveals 160ms, translateY(14px), ease-out */
  --reveal-dist: 14px;
  --reveal-dur:  160ms;
  --ease-out:    cubic-bezier(0.22, 1, 0.36, 1);
}

/* --------------------------------------------------------------------------
   2. Base
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  /* Sticky nav is 70px; keep anchored headings clear of it. */
  scroll-padding-top: 90px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  text-wrap: balance;
}

h1 {
  font-size: var(--fs-display);
  line-height: 1.06;
  letter-spacing: -0.022em;   /* brief §5: tight tracking */
  margin: 0 0 var(--s-4);
}

h2 {
  font-size: var(--fs-headline);
  line-height: 1.12;
  letter-spacing: -0.018em;
  margin: 0 0 var(--s-3);
}

h3 {
  font-size: var(--fs-lg);
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 0;
}

p { margin: 0; }

a {
  color: #7cbcff;
  text-decoration: none;
  transition: color 160ms var(--ease-out);
}
a:hover { color: #a9d2ff; }

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

b, strong { color: var(--text); font-weight: 600; }

/* Visible focus for every interactive element. */
:where(a, button, [tabindex]):focus-visible {
  outline: 2px solid var(--azure);
  outline-offset: 3px;
  border-radius: var(--r-xs);
}

.skip-link {
  position: absolute;
  inset-inline-start: -9999px;
  top: 0;
  z-index: 100;
  padding: 12px 20px;
  background: var(--surface);
  border: 1px solid var(--azure);
  border-radius: 0 0 var(--r-xs) 0;
  color: var(--text);
  font-weight: 600;
}
.skip-link:focus {
  inset-inline-start: 0;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.block-gap    { margin-top: var(--s-7); }
.block-gap-lg { margin-top: var(--s-8); }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

/* --------------------------------------------------------------------------
   3. Motion keyframes
   -------------------------------------------------------------------------- */
@keyframes nhFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50%      { transform: translateY(-16px) rotate(1.2deg); }
}
@keyframes nhAurora1 {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50%      { transform: translate(6vw, 4vh) scale(1.15); }
}
@keyframes nhAurora2 {
  0%, 100% { transform: translate(0, 0) scale(1.1); }
  50%      { transform: translate(-7vw, -3vh) scale(1); }
}
@keyframes nhShimmer {
  0%   { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

/* --------------------------------------------------------------------------
   4. Aurora backdrop
   -------------------------------------------------------------------------- */
.backdrop {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.backdrop::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 50% -10%, rgba(77, 163, 255, 0.05), transparent 55%),
    radial-gradient(ellipse at 50% 120%, rgba(11, 15, 20, 0.90),   transparent 40%);
}

.aurora {
  position: absolute;
  border-radius: 50%;
  will-change: transform;
}
.aurora-1 {
  top: -18%;
  inset-inline-start: -12%;
  width: 60vw;
  height: 60vw;
  background: radial-gradient(circle at 50% 50%, rgba(77, 163, 255, 0.16), transparent 62%);
  filter: blur(40px);
}
.aurora-2 {
  top: 20%;
  inset-inline-end: -16%;
  width: 55vw;
  height: 55vw;
  background: radial-gradient(circle at 50% 50%, rgba(139, 92, 246, 0.15), transparent 62%);
  filter: blur(46px);
}

/* Cursor-tracked ambient light. Pointer devices only. */
.cursor-glow {
  position: fixed;
  top: 0;
  inset-inline-start: 0;
  z-index: 2;
  width: 520px;
  height: 520px;
  margin: -260px 0 0 -260px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(77, 163, 255, 0.09), transparent 60%);
  pointer-events: none;
  opacity: 0;
  transition: opacity 400ms var(--ease-out);
  will-change: transform;
}

.page { position: relative; z-index: 3; }

/* --------------------------------------------------------------------------
   4. Navigation
   -------------------------------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 15, 20, 0.45);
  /* Blur here is functional: content scrolls beneath a translucent bar. */
  -webkit-backdrop-filter: blur(26px);
  backdrop-filter: blur(26px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  transition: background 240ms var(--ease-out),
              border-color 240ms var(--ease-out),
              box-shadow 240ms var(--ease-out);
}

.nav.is-scrolled {
  background: rgba(11, 15, 20, 0.78);
  border-bottom-color: rgba(255, 255, 255, 0.10);
  box-shadow: var(--shadow-2);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: var(--s-6);
  min-height: 70px;
}

.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-2xl);
  letter-spacing: -0.01em;
}
.nav-logo:hover { color: var(--text); }

/* Cube mark — the shipped product logo. Width/height are set on the element
   so it reserves space before decode and never shifts layout. */
.nav-mark {
  flex: none;
  width: 40px;
  height: 40px;
  object-fit: contain;
  filter: drop-shadow(0 0 10px rgba(77, 163, 255, 0.5));
}

/* Gradient on the wordmark only — a logo accent (brief §4), at display weight.
   Body copy never uses it. */
.wordmark-accent {
  background: var(--nebula);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-links {
  display: flex;
  gap: var(--s-6);
  list-style: none;
  margin: 0 0 0 auto;
  padding: 0;
}
.nav-links a {
  color: var(--muted);
  font-size: var(--fs-md);
  font-weight: 500;
}
.nav-links a:hover { color: var(--text); }

/* --------------------------------------------------------------------------
   5. Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 26px;
  border-radius: var(--r-pill);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--fs-base);
  line-height: 1;
  cursor: pointer;
  transition: transform 160ms var(--ease-out),
              box-shadow 160ms var(--ease-out),
              border-color 160ms var(--ease-out),
              background-color 160ms var(--ease-out);
}

.btn-primary {
  background: var(--nebula);
  color: #0b0f14;
  border: 1px solid transparent;
  box-shadow: var(--shadow-1);
}
.btn-primary:hover {
  color: #0b0f14;
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}

.btn-secondary {
  background: rgba(18, 24, 33, 0.60);
  color: var(--text);
  border: 1px solid var(--line-strong);
}
.btn-secondary:hover {
  color: var(--text);
  border-color: var(--azure);
  transform: translateY(-2px);
}

.btn-sm { padding: 9px 18px; font-size: var(--fs-sm); }

.btn:active { transform: translateY(0); }

/* --------------------------------------------------------------------------
   6. Hero
   -------------------------------------------------------------------------- */
.hero {
  position: relative;
  overflow: hidden;
  min-height: 86vh;
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line);
}

.hero-texture {
  position: absolute;
  inset: 0;
  background: url('images/hero-scan.webp') center right / cover no-repeat;
  opacity: 0.5;
  mix-blend-mode: screen;
  will-change: transform;
}

.hero-scrim {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg,
    rgba(11, 15, 20, 0.55) 0%,
    rgba(11, 15, 20, 0.15) 45%,
    rgba(11, 15, 20, 0.45) 100%);
}

/* The signature move — brief §6: one floor lights and sweeps through a
   wireframe building. This is the page's single authored moment.
   It occupies a band at the foot of the hero so the skyline reads as a
   horizon beneath the copy, never as texture behind it. */
.hero-canvas {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 1;
  width: 100%;
  height: 38%;
  opacity: 0.9;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding: 120px var(--gutter) 210px;
  text-align: center;
}

.hero h1 { margin-bottom: var(--s-4); }

/* Display-size gradient only (brief §4: "keep gradient text to display sizes"). */
.hero-accent {
  background: var(--nebula);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* Travelling sheen across the hero headline. */
.hero-accent-shimmer {
  background: linear-gradient(100deg, var(--azure), var(--violet), var(--azure));
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: nhShimmer 6s linear infinite;
}

.hero-lede {
  font-size: var(--fs-xl);
  color: var(--muted);
  max-width: 62ch;
  margin: 0 auto var(--s-5);
}

.hero-descriptor {
  color: var(--muted);
  font-size: var(--fs-base);
  max-width: 68ch;
  margin: 0 auto var(--s-6);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  justify-content: center;
  margin-bottom: var(--s-7);
}

.hero-proof {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  justify-content: center;
  list-style: none;
  margin: 0 auto var(--s-5);
  padding: 0;
  max-width: 640px;
  font-size: var(--fs-md);
  color: var(--muted);
}
.hero-proof li {
  display: flex;
  align-items: center;
  gap: 9px;
}
.hero-proof li::before {
  content: '';
  flex: none;
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--nebula);
}

.hero-products {
  font-size: var(--fs-sm);
  color: var(--muted);
  letter-spacing: 0.04em;
  margin: 0;
}

/* --------------------------------------------------------------------------
   7. Sections
   -------------------------------------------------------------------------- */
.section {
  padding: var(--s-10) 0;
  border-top: 1px solid var(--line);
  position: relative;
}

.section-head {
  max-width: 700px;
  margin-bottom: var(--s-8);
}
.section-head p {
  color: var(--muted);
  max-width: 68ch;
}

/* --------------------------------------------------------------------------
   8. Spec rows — the workhorse list pattern
   -------------------------------------------------------------------------- */
.specs {
  list-style: none;
  margin: 0 0 var(--s-7);
  padding: 0;
  border-top: 1px solid var(--line);
}

.spec {
  display: grid;
  grid-template-columns: minmax(200px, 300px) 1fr;
  gap: 12px var(--s-7);
  padding: var(--s-5) 0;
  border-bottom: 1px solid var(--line);
}
.spec > div { min-width: 0; }
.spec h3 { margin-bottom: var(--s-2); }
.spec p { color: var(--muted); font-size: var(--fs-base); }

/* Definition-list variant (Platform section) */
.deflist { margin: 0; }
.def-row {
  display: grid;
  grid-template-columns: minmax(200px, 300px) 1fr;
  gap: 8px var(--s-7);
  padding: 22px 0;
  border-top: 1px solid var(--line);
}
.def-row:last-child { border-bottom: 1px solid var(--line); }
.def-row > * { min-width: 0; }
.def-row dt {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-lg);
  color: var(--text);
}
.def-row dd {
  margin: 0;
  color: var(--muted);
  font-size: var(--fs-base);
}

/* Big-statement rows (Cross-domain "One alarm queue." etc.) */
.claims {
  border-top: 1px solid var(--line);
  margin-bottom: var(--s-8);
}
.claim {
  display: grid;
  grid-template-columns: minmax(240px, 420px) 1fr;
  gap: 8px var(--s-7);
  align-items: baseline;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}
.claim > * { min-width: 0; }
.claim h3 {
  font-size: var(--fs-statement);
  letter-spacing: -0.015em;
}
.claim p { color: var(--muted); font-size: var(--fs-base); }

/* --------------------------------------------------------------------------
   9. Small type: caveats, chips, tokens
   -------------------------------------------------------------------------- */

/* Caveats keep full --muted colour (~7:1). Size and placement carry the
   demotion — never opacity, which would drop text under 4.5:1. */
.caveat {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-xs);
  color: var(--muted);
}

/* Format identifiers (.nhlic / .nhpkg / .nhflo) — real data, so monospace
   is doing a job here rather than dressing as "technical". */
.token {
  display: inline-block;
  font-family: ui-monospace, 'SF Mono', 'Cascadia Mono', Menlo, monospace;
  font-size: var(--fs-xs);
  color: var(--azure);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--r-xs);
  padding: 1px 9px;
}

.chip {
  display: inline-block;
  font-size: var(--fs-2xs);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-radius: var(--r-pill);
  padding: 3px 11px;
  color: var(--muted);
  border: 1px solid var(--line);
  background: var(--surface-2);
}
.chip-committed {
  color: var(--text);
  border-color: rgba(139, 92, 246, 0.40);
  background: rgba(139, 92, 246, 0.10);
}
.chip-live {
  color: var(--azure);
  border-color: rgba(77, 163, 255, 0.40);
  background: rgba(77, 163, 255, 0.10);
}
.chip-tier {
  font-size: var(--fs-xs);
  letter-spacing: 0;
  text-transform: none;
  color: var(--text);
  padding: 4px 13px;
}

/* --------------------------------------------------------------------------
   10. Panels
   Solid surfaces. Blur was decorative here (nothing scrolls beneath a
   mid-page panel), so it is gone; depth comes from neutral elevation.
   -------------------------------------------------------------------------- */
.panel {
  position: relative;
  background: rgba(18, 24, 33, 0.55);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--r-lg);
  padding: var(--s-6);
  box-shadow: var(--shadow-3), inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.tier.glow-card::before,
.steps li
.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--s-2);
  margin-bottom: var(--s-4);
}
.panel-head h3 { font-size: var(--fs-xl); margin-inline-end: var(--s-1); }

.pull-quote {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--fs-lg);
  color: var(--text);
  max-width: 64ch;
  margin: 0 0 var(--s-5);
}

.modes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-5);
  margin-bottom: var(--s-4);
}
.mode {
  border-top: 1px solid var(--line);
  padding-top: 15px;
  min-width: 0;
}
.mode-name {
  display: block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-sm);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--azure);
  margin-bottom: 9px;
}
.mode p { color: var(--muted); font-size: var(--fs-md); }

/* Dashed advisory note */
.note {
  margin: var(--s-6) 0 0;
  padding: var(--s-4) 22px;
  border: 1px dashed var(--line);
  border-radius: var(--r-md);
  color: var(--muted);
  font-size: var(--fs-md);
}

/* --------------------------------------------------------------------------
   11. Cross-domain section
   -------------------------------------------------------------------------- */

/* The node art is deliberately bled off the edge; clip it here so the
   document never gains horizontal scroll. */
.section-clip { overflow: hidden; }

.section-body { position: relative; z-index: 1; }

.pack {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: var(--s-7);
  align-items: center;
}
.pack > * { min-width: 0; }
.pack h3 {
  font-size: var(--fs-2xl);
  letter-spacing: -0.015em;
  margin: var(--s-3) 0 var(--s-2);
}
.pack p { color: var(--muted); margin-bottom: 12px; }

/* Signal path: certified panel -> EdgeLink -> PlatformCore -> live twin */
.path {
  display: flex;
  flex-direction: column;
  list-style: none;
  margin: 0;
  padding: 0;
}
.path li {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  padding: 13px 18px;
  font-size: var(--fs-md);
  font-weight: 500;
  color: var(--text);
  text-align: center;
}
.path li + li { margin-top: 28px; }
.path li + li::before {
  content: '';
  position: absolute;
  top: -28px;
  inset-inline-start: 50%;
  width: 1px;
  height: 28px;
  background: linear-gradient(180deg, var(--line), var(--azure));
}
.path li:last-child {
  border-color: rgba(77, 163, 255, 0.45);
  background: rgba(77, 163, 255, 0.08);
}

/* Domain roadmap sequence */
.roadmap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.roadmap li {
  display: flex;
  align-items: center;
  gap: 12px;
}
.roadmap li:not(:last-child)::after {
  content: '\2192';
  color: var(--muted);
}
.roadmap span {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-pill);
  padding: 6px 15px;
}

.subhead {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: var(--s-4);
}
.subhead h3 { font-size: var(--fs-lg); }

/* --------------------------------------------------------------------------
   12. Digital twin section
   -------------------------------------------------------------------------- */
.twin-grid {
  display: grid;
  grid-template-columns: 5fr 6fr;
  gap: var(--s-8);
  align-items: center;
}
.twin-grid > * { min-width: 0; }

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--s-4);
}
.feature-list li {
  position: relative;
  padding-inline-start: 22px;
  color: var(--muted);
  font-size: var(--fs-base);
}
.feature-list li::before {
  content: '';
  position: absolute;
  inset-inline-start: 0;
  top: 0.42em;
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--nebula);
}

.mock {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 10px;
  box-shadow: var(--shadow-3);
}
.mock svg { width: 100%; height: auto; border-radius: var(--r-sm); }

/* Commissioning sequence. The numbers carry real order. */
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-4);
}
.steps li {
  position: relative;
  min-width: 0;
  background: rgba(18, 24, 33, 0.55);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--r-md);
  padding: var(--s-5);
  box-shadow: var(--shadow-2);
}
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--nebula);
  color: #0b0f14;
  font-family: var(--font-display);
  font-weight: 600;
  margin-bottom: var(--s-3);
}
.steps h3 { font-size: var(--fs-lg); margin-bottom: var(--s-1); }
.steps p { color: var(--muted); font-size: var(--fs-md); }

.steps-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-xl);
  margin: 0 0 var(--s-4);
}

/* --------------------------------------------------------------------------
   13. White-label section
   -------------------------------------------------------------------------- */
.tiers {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: var(--s-6);
}
.tier {
  position: relative;
  background: rgba(18, 24, 33, 0.55);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--r-lg);
  padding: var(--s-6);
  box-shadow: var(--shadow-2);
  min-width: 0;
}
.tier h3 { font-size: var(--fs-xl); margin: var(--s-3) 0 8px; }
.tier p { color: var(--muted); font-size: var(--fs-md); }

.mechanism {
  color: var(--muted);
  font-size: var(--fs-md);
  max-width: 72ch;
  margin-bottom: var(--s-6);
}

.fixed-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: var(--s-4) 22px;
}
.fixed-label {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-sm);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text);
}
.fixed-bar ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: var(--fs-sm);
  color: var(--muted);
}
.fixed-bar li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.fixed-bar li::before {
  content: '';
  flex: none;
  width: 6px; height: 6px;
  background: var(--muted);
  transform: rotate(45deg);
}

/* --------------------------------------------------------------------------
   14. Region section
   -------------------------------------------------------------------------- */
.region-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-7);
}
.region-grid > div {
  border-top: 1px solid var(--line);
  padding-top: var(--s-4);
  min-width: 0;
}
.region-grid h3 { font-size: var(--fs-lg); margin-bottom: var(--s-2); }
.region-grid p { color: var(--muted); font-size: var(--fs-md); }

.lang-pair {
  display: inline-block;
  background: linear-gradient(100deg, rgba(77, 163, 255, 0.14), rgba(139, 92, 246, 0.14));
  border: 1px solid rgba(77, 163, 255, 0.35);
  border-radius: var(--r-pill);
  padding: 3px 12px;
  font-size: var(--fs-md);
}

/* --------------------------------------------------------------------------
   15. Closing call to action
   -------------------------------------------------------------------------- */
.cta {
  text-align: center;
  padding: 104px 0;
  border-top: 1px solid var(--line);
  position: relative;
  overflow: hidden;
}
.cta::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(77, 163, 255, 0.10), transparent 60%);
  pointer-events: none;
}
.cta > .wrap { position: relative; }
.cta-mark {
  width: 88px;
  height: 88px;
  object-fit: contain;
  margin: 0 auto var(--s-5);
  filter: drop-shadow(0 6px 24px rgba(77, 163, 255, 0.5));
  animation: nhFloat 8s ease-in-out infinite;
  will-change: transform;
}
.cta h2 { margin-bottom: var(--s-3); }
.cta p {
  color: var(--muted);
  max-width: 52ch;
  margin: 0 auto var(--s-5);
}
.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
  justify-content: center;
}

/* --------------------------------------------------------------------------
   16. Footer
   -------------------------------------------------------------------------- */
.footer {
  border-top: 1px solid var(--line);
  padding: var(--s-8) 0;
  color: var(--muted);
  font-size: var(--fs-sm);
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-5);
  align-items: flex-start;
  justify-content: space-between;
}
.footer-brand { max-width: 400px; }
.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-lg);
  color: var(--text);
}
.footer-logo sup { font-size: 0.6em; color: var(--muted); }
.footer-mark {
  flex: none;
  width: 28px;
  height: 28px;
  object-fit: contain;
}
.footer p { margin: 0; }
.footer-brand p { font-size: var(--fs-xs); margin-top: 12px; }
.footer-contact p + p { margin-top: 4px; }
.footer-contact .legal { font-size: var(--fs-xs); }
.footer a { color: var(--muted); }
.footer a:hover { color: var(--text); }

/* --------------------------------------------------------------------------
   17. Back to top
   -------------------------------------------------------------------------- */
.to-top {
  position: fixed;
  bottom: 26px;
  inset-inline-end: 26px;
  z-index: 60;
  width: 48px; height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(18, 24, 33, 0.82);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  box-shadow: var(--shadow-2);
  transition: opacity 240ms var(--ease-out),
              transform 240ms var(--ease-out),
              visibility 240ms,
              border-color 160ms var(--ease-out);
}
.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.to-top:hover { border-color: var(--azure); }

/* --------------------------------------------------------------------------
   18. Reveal — brief §6: 160ms, translateY(14px) + fade, ease-out, once
   -------------------------------------------------------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(var(--reveal-dist));
  transition: opacity var(--reveal-dur) var(--ease-out),
              transform var(--reveal-dur) var(--ease-out);
}
.reveal.is-in {
  opacity: 1;
  transform: none;
}
/* No-JS and pre-observer safety: content is never left invisible.
   GSAP, when it loads, takes over these elements and animates them itself. */
.no-js .reveal { opacity: 1; transform: none; }

/* --------------------------------------------------------------------------
   19. Responsive
   -------------------------------------------------------------------------- */
@media (max-width: 1040px) {
  .pack,
  .twin-grid { grid-template-columns: 1fr; gap: var(--s-7); }
}

@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-inner { gap: var(--s-4); }
  .nav-logo { margin-inline-end: auto; }
  .modes,
  .region-grid { grid-template-columns: 1fr; gap: var(--s-5); }
  .steps { grid-template-columns: 1fr; gap: var(--s-5); }
  .tiers { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  :root { --gutter: 20px; }
  .hero-inner { padding: 104px var(--gutter) 88px; }
  .section { padding: var(--s-9) 0; }
  .cta { padding: 80px 0; }
  .spec,
  .def-row,
  .claim { grid-template-columns: 1fr; gap: 8px; }
  .spec { padding: var(--s-4) 0; }
  .footer-inner { flex-direction: column; gap: var(--s-6); }
  .fixed-bar { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 460px) {
  .hero-actions .btn,
  .cta-actions .btn { width: 100%; }
  .to-top { bottom: 16px; inset-inline-end: 16px; }
}

/* --------------------------------------------------------------------------
   20. Reduced motion — brief §6: honoured everywhere
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1 !important; transform: none !important; }
  .btn:hover { transform: none; }
  .aurora,
  .cta-mark,
  .hero-accent-shimmer { animation: none !important; }
  .cursor-glow { display: none; }
}

/* Coarse pointers get no cursor light — there is no cursor to track. */
@media (hover: none), (pointer: coarse) {
  .cursor-glow { display: none; }
}

/* --------------------------------------------------------------------------
   21. Print
   -------------------------------------------------------------------------- */
@media print {
  .backdrop, .to-top, .hero-canvas, .hero-texture,   .cursor-glow { display: none; }
  body { background: #fff; color: #000; }
  .reveal { opacity: 1; transform: none; }
}

/* ==========================================================================
   v4 additions
   ========================================================================== */

/* --------------------------------------------------------------------------
   Proof strip - what the hero used to carry, given its own band below the fold
   -------------------------------------------------------------------------- */
.proof-strip {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(18, 24, 33, 0.35);
  padding: var(--s-7) 0;
}
.proof-strip-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  gap: var(--s-5) var(--s-8);
  align-items: start;
}
.proof-lede {
  grid-column: 1;
  grid-row: 1;
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 500;
  font-size: var(--fs-lg);
  line-height: 1.35;
  max-width: 34ch;
}
.proof-list {
  grid-column: 2;
  grid-row: 1;
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--s-3) var(--s-5);
}
.proof-list li {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  color: var(--muted);
  font-size: var(--fs-md);
  min-width: 0;
}
.proof-mark {
  flex: none;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--nebula);
}
.proof-products {
  color: var(--muted);
  font-size: var(--fs-xs);
  letter-spacing: 0.04em;
}

/* --------------------------------------------------------------------------
   Full-bleed survey band - the one photographic moment on the page
   -------------------------------------------------------------------------- */
.survey {
  position: relative;
  min-height: 62vh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.survey-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  opacity: 0.68;
  will-change: transform;
}
.survey-scrim {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, var(--bg) 0%, rgba(11, 15, 20, 0.72) 42%, rgba(11, 15, 20, 0.15) 100%),
    linear-gradient(0deg,  var(--bg) 2%,  rgba(11, 15, 20, 0.10) 55%);
}
.survey-inner {
  position: relative;
  padding-block: var(--s-9);
  max-width: var(--wrap);
  width: 100%;
}
.survey-inner h2 { max-width: 16ch; }
.survey-inner p {
  color: var(--muted);
  max-width: 52ch;
}

/* --------------------------------------------------------------------------
   Commissioning flow - a connected sequence, not three identical cards
   -------------------------------------------------------------------------- */
.flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--s-6);
  position: relative;
}
.flow::before {
  content: '';
  position: absolute;
  top: 15px;
  inset-inline: 8%;
  height: 1px;
  background: linear-gradient(90deg, var(--line), var(--azure), var(--line));
  opacity: 0.5;
}
.flow li {
  position: relative;
  min-width: 0;
  padding-top: var(--s-6);
}
.flow-step {
  position: absolute;
  top: 0;
  inset-inline-start: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--azure);
  color: var(--azure);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-sm);
}
.flow h3 { font-size: var(--fs-lg); margin-bottom: var(--s-1); }
.flow p { color: var(--muted); font-size: var(--fs-md); }

/* --------------------------------------------------------------------------
   Platform matrix - 2x2 hairline grid, distinct from the spec-row family
   -------------------------------------------------------------------------- */
.matrix {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 1px solid var(--line);
  border-inline-start: 1px solid var(--line);
}
.matrix-cell {
  border-inline-end: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: var(--s-6);
  min-width: 0;
}
.matrix dt {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-lg);
  color: var(--text);
  margin-bottom: var(--s-2);
}
.matrix dd {
  margin: 0;
  color: var(--muted);
  font-size: var(--fs-md);
}

@media (max-width: 900px) {
  .proof-strip-inner { grid-template-columns: 1fr; }
  /* explicit placements above must not survive the collapse */
  .proof-lede,
  .proof-list,
  .proof-products { grid-column: 1 / -1; grid-row: auto; }
  .proof-lede { max-width: none; }
  .proof-list { grid-template-columns: 1fr 1fr; }
  .flow { grid-template-columns: 1fr; gap: var(--s-5); }
  .flow::before { display: none; }
  .matrix { grid-template-columns: 1fr; }
  .survey { min-height: 52vh; }
}

@media (max-width: 760px) {
  .proof-list { grid-template-columns: 1fr; }
  .matrix-cell { padding: var(--s-5); }
}

@media (prefers-reduced-motion: reduce) {
  .survey-img { transform: none !important; }
}

/* Product family. Hairline dividers rather than a run of middle-dots -
   the separator language the rest of the system already uses. */
.proof-products {
  grid-column: 1 / -1;
  padding-top: var(--s-4);
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  row-gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
  color: var(--muted);
  font-size: var(--fs-xs);
  letter-spacing: 0.04em;
}
.proof-products li { padding-inline: var(--s-3); }
.proof-products li:first-child { padding-inline-start: 0; }
.proof-products li + li { border-inline-start: 1px solid var(--line-strong); }

/* Below 760px each product sits on its own line, so the vertical hairline
   would read as a stray tick at the start of every row. Stack instead. */
@media (max-width: 760px) {
  .proof-products {
    display: grid;
    grid-template-columns: 1fr 1fr;
    row-gap: 6px;
    column-gap: var(--s-4);
  }
  .proof-products li,
  .proof-products li:first-child { padding-inline: 0; }
  .proof-products li + li { border-inline-start: 0; }
}

/* Flex items default to min-width:auto, so these labels refused to shrink and
   pushed the document wider than the viewport at 390px. */
.proof-list li > span {
  min-width: 0;
  overflow-wrap: break-word;
}

/* ==========================================================================
   Post-critique pass
   ========================================================================== */

/* A dead mailto must never be the end of the road. */
.cta-fallback {
  margin-top: var(--s-4);
  color: var(--muted);
  font-size: var(--fs-sm);
}
.cta-fallback a {
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--line-strong);
}
.cta-fallback a:hover { color: var(--text); text-decoration-color: var(--azure); }

/* Example interface languages. Neutral by design: this is not live-state, so it
   must not wear the azure/nebula dress the system reserves for that. */
.lang-set {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2) var(--s-4);
  list-style: none;
  margin: var(--s-3) 0 0;
  padding: 0;
  color: var(--muted);
  font-size: var(--fs-md);
}
.lang-set li { display: flex; align-items: center; gap: var(--s-2); }
.lang-code {
  font-family: ui-monospace, 'SF Mono', Menlo, monospace;
  font-size: var(--fs-2xs);
  letter-spacing: 0.08em;
  color: var(--muted);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: var(--r-xs);
  padding: 1px 7px;
}

/* Nav: active section. Azure marks "where you are", which is what the system
   says azure is for. */
.nav-links a[aria-current="true"] {
  color: var(--azure);
}

/* Nav CTA measured 124x34 at 390px, under the 44px tap-target floor. */
@media (max-width: 900px) {
  .nav .btn-sm { padding-block: 14px; }
}

/* Compact section row, phones only. The full nav is hidden below 900px and this
   restores wayfinding without a menu system. */
.nav-compact { display: none; }
@media (max-width: 900px) {
  .nav-compact {
    display: block;
    border-top: 1px solid var(--line);
    background: rgba(11, 15, 20, 0.55);
  }
  .nav-compact ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0 var(--gutter);
    gap: var(--s-5);
    overflow-x: auto;
    scrollbar-width: none;
  }
  .nav-compact ul::-webkit-scrollbar { display: none; }
  .nav-compact a {
    display: block;
    padding: 11px 0;
    white-space: nowrap;
    color: var(--muted);
    font-size: var(--fs-sm);
    font-weight: 500;
  }
  .nav-compact a[aria-current="true"] { color: var(--azure); }
}

/* Roadmap arrows were dangling at line ends, breaking the sequence metaphor
   exactly where it wrapped. Bind each arrow to the chip before it. */
.roadmap li { flex-wrap: nowrap; }
.roadmap li:not(:last-child)::after { flex: none; }

/* Hover is feedback, so it stays; it is now a border shift rather than a
   pointer-tracked radial. Same signal, none of the ambient garnish. */
.panel, .tier, .flow li {
  transition: border-color 200ms var(--ease-out);
}
.panel:hover, .tier:hover { border-color: var(--line-strong); }

/* The survey image is scaled by the scroll tween, so its painted box exceeds
   the section. Assert the clip with higher specificity and use `clip`, which
   cannot be turned into a scroll container. */
section.survey { overflow: clip; }