/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--paper);
  color: var(--graphite);
  font-size: var(--fs-body);
  line-height: 1.55;
  font-feature-settings: 'ss01', 'cv11';
}

h1, h2, h3 { color: var(--ink); font-weight: 400; letter-spacing: -0.02em; }
h1 { font-size: var(--fs-h1);      line-height: 1.1; }
h2 { font-size: var(--fs-h2);      line-height: 1.2; }
h3 { font-size: var(--fs-h3);      line-height: 1.3; font-weight: 500; letter-spacing: -0.01em; }

p { color: var(--slate); }

a { color: inherit; text-decoration: none; transition: color var(--dur-out) var(--ease); }
a:hover { color: var(--ink); }

svg { display: block; }

/* ============================================================
   UTILITIES
   ============================================================ */
.wrap {
  width: 100%;
  max-width: var(--grid-max);
  margin: 0 auto;
  padding-inline: var(--sp-lg);
}

.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--slate);
}

.rule {
  height: 1px;
  background: var(--line);
  opacity: 0.5;
  border: 0;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(247, 245, 240, 0.82);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-out) var(--ease);
}
.nav[data-scrolled="true"] { border-bottom-color: var(--mist); }
.nav__inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px;
}
.nav__left { display: flex; align-items: center; gap: var(--sp-2xl); }
.nav__links { display: flex; gap: var(--sp-xl); }
.nav__links a {
  font-size: var(--fs-body); color: var(--slate);
  position: relative; padding-block: 4px;
  transition: color var(--dur-in) var(--ease);
}
.nav__links a::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 100%; height: 1px; background: var(--steel-blue);
  transform: scaleX(0); transform-origin: left;
  transition: transform var(--dur-in) var(--ease);
}
.nav__links a:hover { color: var(--ink); }
.nav__links a:hover::after { transform: scaleX(1); }
.nav__right { display: flex; align-items: center; gap: var(--sp-md); }

.logo {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--ink);
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: var(--sp-sm);
  padding: 10px var(--sp-md);
  font-size: var(--fs-body);
  font-family: var(--font-sans);
  line-height: 1;
  border: 1px solid transparent;
  border-radius: 2px;
  cursor: pointer;
  transition: background-color var(--dur-in) var(--ease),
              border-color var(--dur-in) var(--ease),
              color var(--dur-in) var(--ease);
  white-space: nowrap;
}
.btn--primary {
  background: var(--steel-blue); color: var(--paper); border-color: var(--steel-blue);
}
.btn--primary:hover { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.btn--ghost {
  background: transparent; color: var(--ink); border-color: var(--line);
}
.btn--ghost:hover { border-color: var(--ink); color: var(--ink); }
.btn--lg { padding: 15px 22px; font-size: var(--fs-body-l); }
.btn .icon { width: 16px; height: 16px; transition: transform var(--dur-in) var(--ease); }
.btn:hover .icon { transform: translateX(3px); }

@media (max-width: 760px) { .nav__links { display: none; } }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  padding-top: var(--sp-4xl); padding-bottom: var(--sp-4xl);
  overflow: hidden;
  /* fine drafting grid + a heavier module line every 96px */
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px),
    linear-gradient(var(--grid-line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line-soft) 1px, transparent 1px);
  background-size: 96px 96px, 96px 96px, 24px 24px, 24px 24px;
}
/* fade the grid out behind the headline text and toward the bottom
   so it doesn't fight the typography */
.hero::after {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 58% 75% at 24% 42%, var(--paper) 0%, rgba(247, 245, 240, 0.85) 45%, transparent 78%),
    linear-gradient(180deg, transparent 55%, var(--paper) 100%);
  pointer-events: none;
}
.hero > .wrap { position: relative; z-index: 1; }
.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: var(--sp-3xl);
  align-items: center;
}
@media (max-width: 960px) { .hero__grid { grid-template-columns: 1fr; gap: var(--sp-2xl); } }

.hero__title {
  font-size: var(--fs-display);
  line-height: 1.05;
  letter-spacing: -0.025em;
  color: var(--ink);
  font-weight: 400;
  margin-top: 0;
}
.hero__title em { font-style: normal; color: var(--steel-blue); }
.hero__sub {
  font-size: var(--fs-body-l);
  line-height: 1.5;
  color: var(--slate);
  max-width: 56ch;
  margin-top: var(--sp-lg);
}
.hero__ctas {
  display: flex; flex-wrap: wrap; gap: var(--sp-md);
  margin-top: var(--sp-xl);
}

/* ============================================================
   TRUST STRIP
   ============================================================ */
.trust {
  padding-block: var(--sp-lg);
  background: var(--mist);
  border-top: 1px solid rgba(156, 153, 144, 0.35);
  border-bottom: 1px solid rgba(156, 153, 144, 0.35);
  overflow: hidden;
}
.trust__inner { display: flex; align-items: center; gap: var(--sp-xl); }
.trust__label {
  flex: 0 0 auto;
  color: var(--slate); white-space: nowrap;
  padding-right: var(--sp-xl);
  border-right: 1px solid var(--line);
}
.trust__viewport {
  flex: 1; overflow: hidden; position: relative;
  mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 6%, #000 94%, transparent);
}
.trust__track {
  display: flex; width: max-content;
  animation: trust-scroll 36s linear infinite;
}
.trust__run { display: flex; gap: var(--sp-2xl); padding-right: var(--sp-2xl); }
.trust__viewport:hover .trust__track { animation-play-state: paused; }
@keyframes trust-scroll { to { transform: translateX(-50%); } }
.trust__logo {
  font-size: var(--fs-body-l);
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--graphite);
  white-space: nowrap;
  display: inline-flex; align-items: center; gap: 12px;
}
.trust__logo::before {
  content: ""; width: 5px; height: 5px;
  background: var(--steel-blue); transform: rotate(45deg); flex: 0 0 auto;
}
@media (prefers-reduced-motion: reduce) {
  .trust__track { animation: none; width: auto; }
  .trust__run { flex-wrap: wrap; padding-right: 0; }
  .trust__dup { display: none; }
  .trust__viewport { mask-image: none; -webkit-mask-image: none; }
}
@media (max-width: 760px) {
  .trust__inner { flex-direction: column; align-items: flex-start; gap: var(--sp-md); }
  .trust__label { border-right: 0; padding-right: 0; }
  .trust__viewport { width: 100%; }
}

/* ============================================================
   SECTION COMMON
   ============================================================ */
section { scroll-margin-top: 84px; }
.section { padding-block: calc(var(--sp-4xl) + var(--sp-md)); }
.section--banded { background: var(--mist); }
.section__head { margin-bottom: var(--sp-3xl); max-width: 720px; }
.section__eyebrow {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--steel-blue);
  margin-bottom: var(--sp-md);
}
.section__eyebrow::before {
  content: "";
  width: 32px; height: 1px;
  background: var(--steel-blue);
  display: inline-block;
}
.section__title { font-size: var(--fs-h2); letter-spacing: -0.02em; max-width: 22ch; }
.section__lede {
  font-size: var(--fs-body-l);
  color: var(--slate);
  margin-top: var(--sp-md);
}

/* ============================================================
   FAQ
   ============================================================ */
.faq {
  display: grid; grid-template-columns: 1fr;
  gap: 0;
  border-top: 1px solid var(--hairline);
}
.faq__item {
  border-bottom: 1px solid var(--hairline);
  padding-block: var(--sp-lg);
  display: grid;
  grid-template-columns: 48px 1fr 2fr;
  gap: var(--sp-xl);
  align-items: baseline;
}
@media (max-width: 760px) {
  .faq__item { grid-template-columns: 1fr; gap: var(--sp-md); }
  .faq__idx { display: none; }
}
.faq__idx {
  font-family: var(--font-mono); font-size: var(--fs-caption);
  color: var(--line); letter-spacing: 0.08em;
  transition: color var(--dur-in) var(--ease);
}
.faq__item:hover .faq__idx { color: var(--steel-blue); }
.faq__q { color: var(--ink); font-size: var(--fs-h3); font-weight: 500; letter-spacing: -0.01em; transition: color var(--dur-in) var(--ease); }
.faq__item:hover .faq__q { color: var(--steel-blue); }
.faq__a { color: var(--slate); font-size: var(--fs-body-l); line-height: 1.6; }

/* ============================================================
   CLOSING CTA
   ============================================================ */
.close {
  position: relative;
  background: var(--ink);
  color: var(--paper);
  padding-block: calc(var(--sp-4xl) + var(--sp-xl));
  overflow: hidden;
  background-image:
    linear-gradient(var(--grid-line-dark) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line-dark) 1px, transparent 1px);
  background-size: 96px 96px;
}
.close::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--steel-blue), var(--glass-blue), transparent 70%);
}
.close__eyebrow {
  display: inline-flex; align-items: center; gap: 12px;
  font-family: var(--font-mono); font-size: var(--fs-caption);
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--glass-blue);
  margin-bottom: var(--sp-lg);
}
.close__eyebrow::before { content: ""; width: 32px; height: 1px; background: var(--glass-blue); }
.close h2 {
  color: var(--paper);
  font-size: var(--fs-display);
  letter-spacing: -0.025em;
  font-weight: 400;
  max-width: 18ch;
  line-height: 1.05;
}
.close .mono { color: var(--line); }
.close p { color: var(--mist-blue); font-size: var(--fs-body-l); max-width: 58ch; margin-top: var(--sp-lg); }
.close__ctas { display: flex; gap: var(--sp-md); flex-wrap: wrap; margin-top: var(--sp-2xl); }
.close .btn--primary { background: var(--paper); color: var(--ink); border-color: var(--paper); }
.close .btn--primary:hover { background: var(--mist); border-color: var(--mist); }
.close .btn--ghost { color: var(--paper); border-color: var(--slate); }
.close .btn--ghost:hover { color: var(--paper); border-color: var(--glass-blue); }

/* ============================================================
   FOOTER
   ============================================================ */
footer {
  background: var(--ink);
  color: var(--line);
  padding-block: var(--sp-2xl) var(--sp-lg);
  border-top: 1px solid var(--graphite);
}
.foot__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--sp-2xl);
  padding-bottom: var(--sp-2xl);
}
@media (max-width: 760px) { .foot__grid { grid-template-columns: 1fr 1fr; } }
.foot__brand .logo { color: var(--paper); }
.foot__brand p { color: var(--line); font-size: var(--fs-body); margin-top: var(--sp-md); max-width: 38ch; }
.foot__col h4 {
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  color: var(--slate);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 400;
  margin-bottom: var(--sp-md);
}
.foot__col ul { list-style: none; display: flex; flex-direction: column; gap: var(--sp-sm); }
.foot__col a { color: var(--mist); font-size: var(--fs-body); transition: color var(--dur-in) var(--ease); }
.foot__col a:hover { color: var(--mist-blue); }
.foot__bottom {
  border-top: 1px solid var(--graphite);
  padding-top: var(--sp-lg);
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: var(--sp-md);
}
.foot__bottom .mono { color: var(--slate); }

/* ============================================================
   3D VIEWER — Mainspring sample artifact (lazy-loaded Three.js).
   Used on both the Automata homepage and the Mainspring page.
   ============================================================ */
.viewer-3d {
  background: var(--paper);
  border: 1px solid var(--mist);
  border-radius: 4px;
  display: flex; flex-direction: column;
  overflow: hidden;
  box-shadow: 0 1px 0 var(--mist);
}
.viewer-3d__head {
  display: flex; align-items: center; justify-content: space-between;
  gap: var(--sp-md);
  padding: var(--sp-md) var(--sp-lg);
  border-bottom: 1px solid var(--mist);
}
.viewer-3d__chip {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: var(--fs-caption);
  color: var(--slate); letter-spacing: 0.08em; text-transform: uppercase;
}
.viewer-3d__name {
  font-family: var(--font-mono); font-size: var(--fs-caption);
  color: var(--ink); letter-spacing: 0.04em;
}
.viewer-3d__canvas {
  position: relative;
  width: 100%;
  flex: 1;
  aspect-ratio: 4 / 3;
  min-height: 320px;
  background: var(--mist);
}
.viewer-3d__canvas canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
}
.viewer-3d__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-md);
  padding: var(--sp-sm) var(--sp-lg);
  border-top: 1px solid var(--mist);
}
.viewer-3d__hint {
  font-family: var(--font-mono); font-size: var(--fs-caption);
  color: var(--slate); letter-spacing: 0.08em; text-transform: uppercase;
}
.viewer-3d__download {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: var(--fs-caption);
  color: var(--ink); letter-spacing: 0.04em; text-transform: uppercase;
  border-bottom: 1px solid var(--ink);
  padding-bottom: 2px;
  transition: color var(--dur-in) var(--ease),
              border-bottom-color var(--dur-in) var(--ease);
}
.viewer-3d__download:hover {
  color: var(--steel-blue);
  border-bottom-color: var(--steel-blue);
}
.viewer-3d__tooltip {
  position: fixed;
  display: none;
  padding: 6px 10px;
  background: var(--ink);
  color: var(--paper);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  letter-spacing: 0.04em;
  line-height: 1.45;
  pointer-events: none;
  z-index: 100;
  max-width: 240px;
}
.viewer-3d__tooltip strong { font-weight: 500; color: var(--paper); }
.viewer-3d__tooltip .dim { color: var(--line); }

/* ============================================================
   MOTION — respect preference
   ============================================================ */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0; transform: translateY(16px);
    transition: opacity 500ms var(--ease), transform 500ms var(--ease);
    transition-delay: calc(var(--stagger, 0) * 70ms);
  }
  .reveal[data-visible="true"] { opacity: 1; transform: none; }
}