/* =========================================================
   Nero Development — Home
   The Data Infrastructure for Physical AI
   ========================================================= */

:root {
  /* Palette */
  --nero-black-1: #101010;
  --nero-black-2: #141414;
  --nero-charcoal-1: #1a1a1a;
  --nero-charcoal-2: #202020;
  --nero-charcoal-3: #232323;
  --nero-charcoal-4: #2b2b2b;
  --nero-charcoal-5: #2f2f2f;
  --nero-charcoal-6: #343434;
  --nero-charcoal-7: #3d3d3d;
  --nero-silver: #AFAFAF;
  --nero-white: #FFFFFF;
  --nero-orange: #FF7538;
  --nero-orange-dim: #e8720c;

  --text-primary: var(--nero-white);
  --text-secondary: var(--nero-silver);
  --text-muted: rgba(255, 255, 255, 0.6);
  --border-subtle: rgba(255, 255, 255, 0.12);
  --border-faint: rgba(255, 255, 255, 0.08);
  --surface-hover: rgba(255, 255, 255, 0.06);

  /* Type families */
  --font: 'Google Sans Flex', 'Google Sans', 'Roboto', Arial, sans-serif;
  --font-mono: 'Roboto Mono', 'Google Sans Flex', monospace;

  /* Fluid type scale */
  --type-display: clamp(2.75rem, 6.2vw + 1rem, 6.5rem);
  --type-h2: clamp(2rem, 3.2vw + 1rem, 3.25rem);
  --type-h2-md: clamp(1.75rem, 2.4vw + 1rem, 2.75rem);
  --type-lead: clamp(1.05rem, 0.6vw + 0.9rem, 1.2rem);
  --type-body: clamp(0.95rem, 0.3vw + 0.85rem, 1rem);
  --type-small: clamp(0.8rem, 0.2vw + 0.75rem, 0.875rem);
  --type-label: 0.6875rem;
  --type-stat: clamp(2.5rem, 4vw + 1rem, 3.5rem);

  /* Rhythm */
  --section-pad-y: clamp(4.5rem, 8vw, 8.75rem);
  --container-x: clamp(1.25rem, 4vw, 3rem);
  --max-width: 1280px;
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  font-weight: 100;
  color: var(--text-primary);
  background: var(--nero-black-1);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }

a { color: var(--nero-orange); text-decoration: none; }
a:hover { color: var(--nero-white); }

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

:focus-visible { outline: 2px solid var(--nero-orange); outline-offset: 3px; }

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

.mono { font-family: var(--font-mono); letter-spacing: 0.5px; }

/* ---------- Layout primitives ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--container-x);
}

.section { padding-block: var(--section-pad-y); }
.section--charcoal { background: var(--nero-charcoal-1); }

.eyebrow {
  font-size: var(--type-label);
  letter-spacing: 1px;
  text-transform: uppercase;
  font-weight: 400;
  color: var(--nero-orange);
  margin-bottom: 1.25rem;
}

.section-title {
  font-size: var(--type-h2);
  font-weight: 200;
  letter-spacing: -0.02em;
  line-height: 1.15;
  max-width: 20ch;
}
.section-title--md { font-size: var(--type-h2-md); }

.lead {
  font-size: var(--type-lead);
  font-weight: 300;
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: 42ch;
  margin-top: 1.25rem;
}
.lead--wide { max-width: 56ch; }

.footnote {
  font-size: var(--type-small);
  color: var(--text-muted);
  margin-top: 1.25rem;
}

/* ---------- Brand mark ---------- */
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand__mark {
  width: 14px;
  height: 14px;
  flex: none;
  background: var(--nero-orange);
  transform: rotate(45deg);
  display: inline-block;
}
.brand__name {
  font-size: 0.875rem;
  letter-spacing: 1.5px;
  color: var(--nero-white);
  white-space: nowrap;
}
.brand__name-dim { color: var(--nero-silver); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 400;
  letter-spacing: 0.3px;
  padding: 0.95em 1.75em;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease, opacity 0.15s ease;
}
.btn--primary { background: var(--nero-orange); color: #fff; }
.btn--primary:hover { background: var(--nero-orange-dim); color: #fff; }
.btn--ghost { border-color: var(--border-subtle); background: var(--surface-hover); color: #fff; }
.btn--ghost:hover { border-color: var(--nero-silver); }
.btn--lg { padding: 1.1em 2.25em; font-size: 0.9375rem; margin-top: 2.25rem; }

.link-arrow {
  display: inline-block;
  margin-top: 1.5rem;
  font-size: 0.8125rem;
  color: var(--nero-orange);
}
.link-arrow:hover { color: var(--nero-white); }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 18px 32px;
  background: rgba(16, 16, 16, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-faint);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  width: 100%;
}

.nav { flex: 1; display: flex; justify-content: center; }
.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  flex: none;
}
.nav__toggle-bar { width: 18px; height: 1.5px; background: var(--nero-white); margin-inline: auto; transition: transform 0.2s ease, opacity 0.2s ease; }

.nav__menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav__group { position: relative; }
.nav__group-label {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  background: none;
  border: none;
  font-family: inherit;
  font-size: 0.8125rem;
  letter-spacing: 0.3px;
  color: var(--text-secondary);
  cursor: pointer;
}
.nav__caret { font-size: 10px; color: var(--nero-charcoal-6); transition: transform 0.15s ease; }

.nav__dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 250px;
  background: var(--nero-charcoal-1);
  border: 1px solid var(--border-subtle);
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity 0.15s ease, transform 0.15s ease, visibility 0.15s;
}
.nav__group:hover .nav__dropdown,
.nav__group:focus-within .nav__dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.nav__group:hover .nav__group-label,
.nav__group:focus-within .nav__group-label { color: #fff; }
.nav__group:hover .nav__caret,
.nav__group:focus-within .nav__caret { transform: rotate(180deg); }

.nav__item { display: block; padding: 12px 14px; text-decoration: none; }
.nav__item:hover { background: var(--surface-hover); }
.nav__item-name { display: block; font-size: 0.8125rem; font-weight: 400; color: #fff; }
.nav__item-desc { display: block; font-size: 0.75rem; color: var(--nero-silver); margin-top: 4px; }

.nav__cta { flex: none; padding: 10px 18px; font-size: 0.6875rem; letter-spacing: 0.5px; text-transform: uppercase; }
.nav__cta--mobile { display: none; }
.nav__group-label--active { color: #fff; }

/* ---------- Page intro (subpage header) ---------- */
.page-intro { padding: clamp(6rem, 12vw, 7.5rem) var(--container-x) clamp(3rem, 6vw, 5rem); max-width: 1100px; margin-inline: auto; }
.page-intro__title { font-size: clamp(2.25rem, 4.2vw + 1rem, 4.5rem); font-weight: 100; line-height: 1.05; letter-spacing: -1px; max-width: 18ch; }
.page-links { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2.25rem; font-size: 0.8125rem; }
.page-links a { display: inline-block; padding: 12px 22px; border: 1px solid var(--border-subtle); color: #fff; }
.page-links a:hover { border-color: var(--nero-silver); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  height: min(760px, 100svh);
  min-height: 480px;
  overflow: hidden;
}
.hero__bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero__scrim {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(10,10,10,0.55) 0%, rgba(10,10,10,0.35) 40%, rgba(10,10,10,0.88) 100%);
  pointer-events: none;
}
.hero__scrim-bottom {
  position: absolute; left: 0; right: 0; bottom: 0; height: 45%;
  background: linear-gradient(180deg, rgba(10,10,10,0.68) 0%, rgba(10,10,10,0.98) 100%);
  pointer-events: none;
}

.hero__hud {
  position: absolute;
  top: 120px;
  font-size: 11px;
  color: rgba(255, 255, 255, 0.55);
  line-height: 1.8;
  pointer-events: none;
}
.hero__hud--left { left: 32px; }
.hero__hud--right { right: 32px; text-align: right; }

.hero__content {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 0 32px clamp(2.5rem, 6vw, 4rem);
}
.hero__headline {
  font-size: var(--type-display);
  line-height: 0.98;
  font-weight: 100;
  letter-spacing: -1px;
  max-width: 20ch;
}
.hero__sub {
  font-size: clamp(1rem, 1vw + 0.75rem, 1.2rem);
  font-weight: 300;
  color: var(--nero-silver);
  max-width: 38ch;
  margin-top: 1.75rem;
  line-height: 1.5;
}
.hero__tags {
  font-size: 0.8125rem;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-top: 1rem;
}
.hero__actions { display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 2.25rem; }

/* ---------- Problem flow ---------- */
.flow {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-top: 3.5rem;
  font-size: 0.9375rem;
  letter-spacing: 1px;
  color: var(--text-secondary);
}
.flow__arrow { color: var(--nero-orange); }
.flow__accent { color: #fff; }

/* ---------- Network ---------- */
.pipeline-flow {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0;
  margin-top: 3.5rem;
  font-size: 0.875rem;
  letter-spacing: 1px;
  color: var(--text-secondary);
}
.pipeline-flow__arrow { margin: 0 16px; color: var(--nero-charcoal-6); }
.pipeline-flow__end { color: #fff; }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--nero-charcoal-6);
  margin-top: 3.5rem;
}
.stat-tile { background: var(--nero-charcoal-1); padding: 2.25rem; }
.stat-tile__label { font-size: var(--type-label); letter-spacing: 1px; text-transform: uppercase; color: var(--text-secondary); }
.stat-tile__value { font-size: 3.25rem; font-weight: 100; margin-top: 14px; letter-spacing: -0.01em; }
.stat-tile__caption { font-size: 0.9375rem; color: var(--text-secondary); margin-top: 4px; }

/* ---------- Capture Systems cards ---------- */
.hw-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--nero-charcoal-6);
  margin-top: 3.5rem;
}
.hw-card { background: var(--nero-black-1); display: flex; flex-direction: column; }
.hw-card__media { aspect-ratio: 3 / 2; background: var(--nero-black-1); overflow: hidden; }
.hw-card__media img { width: 100%; height: 100%; object-fit: cover; }
.hw-card__body { padding: 2rem; }
.hw-card__eyebrow { font-size: var(--type-label); letter-spacing: 1px; text-transform: uppercase; color: var(--text-secondary); }
.hw-card__title { font-size: 1.375rem; font-weight: 300; margin-top: 10px; }
.hw-card__text { font-size: 0.875rem; color: var(--text-secondary); margin-top: 12px; line-height: 1.6; }

/* ---------- Chips ---------- */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 2.5rem;
  list-style: none;
}
.chip {
  padding: 12px 20px;
  border: 1px solid var(--border-subtle);
  font-size: 0.8125rem;
  letter-spacing: 0.5px;
  color: var(--text-secondary);
}

/* ---------- Data Engine pipeline ---------- */
.pipeline-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1px;
  background: var(--nero-charcoal-6);
  margin-top: 3.5rem;
  list-style: none;
}
.pipeline-stage { background: var(--nero-black-1); padding: 24px 20px; min-height: 180px; }
.pipeline-stage__num { font-size: 11px; color: var(--nero-orange); }
.pipeline-stage__name { font-size: 1rem; font-weight: 400; margin-top: 12px; }
.pipeline-stage__desc { font-size: 0.75rem; color: var(--text-secondary); margin-top: 12px; line-height: 1.6; }

/* ---------- Commercial models ---------- */
.model-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--nero-charcoal-6);
  margin-top: 3.5rem;
}
.model-card { background: var(--nero-black-1); padding: 2rem; }
.model-card__num { font-size: var(--type-label); letter-spacing: 1px; color: var(--text-secondary); }
.model-card__title { font-size: 1.125rem; font-weight: 400; margin-top: 16px; }
.model-card__text { font-size: 0.8125rem; color: var(--text-secondary); margin-top: 12px; line-height: 1.6; }
.model-card--highlight { background: var(--nero-orange); }
.model-card--highlight .model-card__num { color: rgba(255, 255, 255, 0.8); }
.model-card--highlight .model-card__title { color: #fff; }
.model-card--highlight .model-card__text { color: rgba(255, 255, 255, 0.85); }

/* ---------- Final CTA ---------- */
.cta { text-align: center; padding-block: clamp(6rem, 12vw, 10rem); }
.cta__headline {
  font-size: clamp(2rem, 3.5vw + 1rem, 3.75rem);
  font-weight: 100;
  letter-spacing: -1px;
  max-width: 20ch;
  margin-inline: auto;
}

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border-faint); padding-block: 3rem; }
.site-footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}
.site-footer .brand__name { color: var(--nero-silver); }
.site-footer__links { display: flex; gap: 1.75rem; flex-wrap: wrap; font-size: 0.8125rem; }
.site-footer__links a { color: var(--nero-silver); }
.site-footer__links a:hover { color: var(--nero-orange); }