/* Brand primitives. Additional logo-spectrum colors require approved values. */
:root {
  --gs-ink: #062640; --gs-black: #101010; --gs-white: #ffffff;
  --gs-off-white: #f5f4f0; --gs-green: #00ff88; --gs-teal: #3eddbd;
  --background: var(--gs-ink); --foreground: var(--gs-white);
  --surface: var(--gs-off-white); --surface-secondary: var(--gs-black);
  --accent: var(--gs-teal); --border: color-mix(in srgb, var(--foreground) 20%, transparent);
  --muted: color-mix(in srgb, var(--gs-ink) 90%, var(--gs-white));
  --muted-foreground: color-mix(in srgb, var(--gs-white) 70%, var(--gs-ink));
  --font-sans: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', monospace;
  --page-gutter: clamp(1.5rem, 4.4vw, 4.5rem); --content-width: 90rem;
  --duration-fast: 180ms; --duration-medium: 400ms; --duration-reveal: 700ms;
  --ease: cubic-bezier(.2,.7,.2,1);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 1.5rem; }
body { margin: 0; background: var(--background); color: var(--foreground); font-family: var(--font-sans); -webkit-font-smoothing: antialiased; }
body.menu-open { overflow: hidden; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
button[hidden] { display: none; }
::selection { background: var(--gs-teal); color: var(--gs-ink); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 6px; }
p, h1, h2, h3 { margin: 0; }
.container { width: min(100%, var(--content-width)); padding-inline: var(--page-gutter); margin-inline: auto; }
.skip-link { position: fixed; top: 1rem; left: 1rem; z-index: 10; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; color: var(--gs-ink); background: var(--gs-teal); }
.skip-link:focus { width: auto; height: auto; padding: 1rem 1.25rem; overflow: visible; clip-path: none; }
#main:focus { outline: none; }
.header { background: var(--background); }
.header__inner { min-height: 88px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--border); gap: 2rem; }
.brand { width: 108px; height: 80px; display: block; position: relative; overflow: hidden; flex-shrink: 0; }
.brand img { position: absolute; width: 118px; height: 118px; max-width: none; left: -5px; top: -22px; }
.desktop-nav { display: flex; align-items: center; gap: clamp(1.5rem, 3vw, 3rem); }
.desktop-nav a, .footer nav a { min-height: 44px; display: inline-flex; align-items: center; font-size: .875rem; transition: color var(--duration-fast); }
.desktop-nav a:hover, .footer a:hover { color: var(--accent); }
.desktop-nav a:last-child { border-left: 1px solid var(--border); padding-left: 2.5rem; }
/* Cap tall-screen expansion; let content determine the minimum on short screens. */
.hero { min-height: min(calc(100svh - 88px), 48rem); display: flex; flex-direction: column; }
.hero__grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: 1.5rem; row-gap: 1.75rem; align-content: center; align-items: center; flex: 1; padding-block: clamp(2.5rem, 6svh, 4.5rem) clamp(2rem, 4svh, 3.5rem); }
.hero__copy { grid-column: 1 / 7; grid-row: 1; position: relative; z-index: 1; animation: enter var(--duration-reveal) var(--ease) both; }
.eyebrow { font-family: var(--font-mono); font-size: .75rem; letter-spacing: .055em; line-height: 1.6; display: flex; gap: .8rem; align-items: center; }
.label-line { width: 24px; height: 2px; background: var(--accent); flex: none; }
h1 { font-size: clamp(3.5rem, 7.25vw, 7rem); line-height: .99; letter-spacing: -.062em; font-weight: 500; margin: 1.65rem 0 1.65rem; }
.accent { color: var(--accent); }
.lead { color: var(--muted-foreground); font-size: clamp(1.125rem, 1.5vw, 1.25rem); line-height: 1.65; max-width: 29rem; }
.hero__actions { display: flex; flex-wrap: wrap; gap: .875rem; margin-top: 2rem; }
.button { display: inline-flex; justify-content: space-between; align-items: center; gap: 1.6rem; min-height: 54px; padding: .875rem 1.125rem; font-size: .875rem; line-height: 1.4; border: 1px solid transparent; transition: background var(--duration-fast), border-color var(--duration-fast); }
.button--primary { background: var(--accent); color: var(--gs-ink); }
.button--primary:hover { background: var(--gs-green); }
.button--secondary { border-color: var(--border); }
.button--secondary:hover { border-color: var(--accent); background: var(--muted); }
.arrow { display: inline-block; font-size: 1.2rem; transition: transform var(--duration-fast) var(--ease); }
a:hover .arrow { transform: translate(2px,-2px); }
.hero__attribution { grid-column: 1 / 7; grid-row: 2; color: var(--muted-foreground); font-size: .75rem; line-height: 1.6; }
.hero__bottom { display: flex; justify-content: space-between; align-items: center; gap: 1rem; min-height: 60px; border-top: 1px solid var(--border); font-family: var(--font-mono); font-size: .75rem; letter-spacing: .035em; color: var(--muted-foreground); }
.hero__bottom a { display: flex; align-items: center; gap: 2rem; min-height: 44px; font-family: var(--font-sans); font-size: .8125rem; letter-spacing: 0; }
.hero__bottom a span { font-size: 1.3rem; color: var(--accent); }
.system { grid-column: 7 / -1; grid-row: 1 / 3; min-width: 0; margin-left: 0; animation: enter var(--duration-reveal) var(--ease) 120ms both; }
.system__heading, .system__caption { display: flex; justify-content: space-between; align-items: center; gap: 1rem; color: var(--muted-foreground); font: .75rem/1.6 var(--font-mono); letter-spacing: .025em; }
.system__heading { padding: 0 0 1.25rem; border-bottom: 1px solid var(--border); }
.system__heading span:last-child { font-size: .6875rem; }
.system__drawing { display: block; width: 100%; height: auto; overflow: visible; }
.grid-line { stroke: var(--foreground); stroke-opacity: .045; stroke-width: 1; }
.plane { stroke: var(--accent); stroke-width: 1; }
.plane--bottom { fill: var(--accent); fill-opacity: .025; stroke-opacity: .2; }
.plane--middle { fill: var(--accent); fill-opacity: .035; stroke-opacity: .35; }
.plane--top { fill: var(--gs-ink); fill-opacity: .9; stroke-opacity: .7; stroke-width: 1.3; }
.field-lines { stroke: var(--accent); stroke-opacity: .44; }
.system-paths { stroke: var(--accent); stroke-width: 1.8; stroke-opacity: .85; }
.activity { stroke: var(--gs-green); stroke-width: 2; stroke-dasharray: 20 600; stroke-dashoffset: 600; animation: path-arrival 3s var(--ease) 700ms both; }
.node { fill: var(--accent); stroke: var(--gs-ink); stroke-width: 3; }
.node--primary { fill: var(--gs-green); }
.node-ring { stroke: var(--accent); stroke-opacity: .3; }
.system-label { stroke: var(--muted-foreground); stroke-opacity: .5; }
.system-label text { stroke: none; fill: var(--muted-foreground); font: 13px var(--font-mono); letter-spacing: 1px; }
.system-label text.system-label--primary { fill: var(--foreground); font-size: 15px; font-weight: 600; }
.crosshairs { display: none; }
.system__caption { padding: .75rem 0 0; font-size: .6875rem; }
.system__key { display: flex; align-items: center; gap: .5rem; }
.system__key i { width: 5px; height: 5px; background: var(--accent); }
.intro { --foreground: var(--gs-ink); --accent: var(--gs-ink); --border: color-mix(in srgb, var(--gs-ink) 20%, transparent); background: var(--surface); color: var(--foreground); padding-block: clamp(4.5rem, 7.5vw, 7.5rem) clamp(5rem, 8vw, 8rem); }
.intro__heading { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 1.5rem; }
.intro__heading .eyebrow { grid-column: span 3; align-self: start; margin-top: .7rem; }
h2 { grid-column: span 9; font-size: clamp(2.5rem, 5.4vw, 5rem); font-weight: 500; letter-spacing: -.05em; line-height: 1.04; max-width: 19ch; text-wrap: balance; }
.intro__body { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 1.5rem; margin-block: clamp(2.75rem, 4.5vw, 4.5rem) clamp(3.5rem, 6vw, 6rem); }
.intro__body > p { grid-column: 4 / 8; max-width: 30ch; }
.intro__body > div { grid-column: 9 / -1; padding-left: 1.5rem; border-left: 1px solid var(--border); }
.intro__body p { font-size: 1.125rem; line-height: 1.65; color: color-mix(in srgb, var(--gs-ink) 78%, var(--gs-off-white)); }
h3 { font-weight: 500; font-size: clamp(1.5rem, 2.1vw, 2rem); letter-spacing: -.03em; line-height: 1.2; margin-bottom: 1.25rem; }
.framework { padding: 0; margin: 0; list-style: none; display: grid; grid-template-columns: repeat(4,1fr); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.framework li { position: relative; padding: 1.75rem 1.75rem 2rem; font-size: clamp(1.3rem, 2.4vw, 2.125rem); letter-spacing: -.04em; }
.framework li::before { content: ''; position: absolute; top: -1px; left: 1.75rem; width: 1.75rem; height: 2px; background: var(--gs-ink); }
.framework li + li { border-left: 1px solid var(--border); }
.framework__number { display: block; font: .75rem var(--font-mono); margin-bottom: 2.25rem; letter-spacing: .05em; }
.framework__arrow, .framework__end { position: absolute; right: 1.75rem; top: 1.5rem; font-size: 1.5rem; }
.framework__end { color: var(--gs-ink); }
.footer { background: var(--gs-black); padding-block: 3rem 1.5rem; }
.footer__main { display: flex; align-items: center; gap: 2rem; padding-bottom: 2.5rem; }
.footer__main p { font-size: .875rem; color: var(--muted-foreground); }
.footer nav { margin-left: auto; display: flex; gap: 1.5rem; flex-wrap: wrap; }
.footer__base { border-top: 1px solid var(--border); display: flex; justify-content: space-between; gap: 1.5rem; padding-top: 1.5rem; font-size: .75rem; color: var(--muted-foreground); }
.footer__base span:last-child { font: .625rem var(--font-mono); letter-spacing: .06em; }
.menu-toggle, .menu-close { min-height: 44px; padding: .5rem 0 .5rem 1rem; background: none; border: 0; color: var(--foreground); display: flex; align-items: center; gap: 1rem; }
.menu-toggle { display: none; }
.mobile-menu { position: fixed; inset: 0; width: 100%; max-width: none; height: 100%; max-height: none; margin: 0; padding: 1.5rem; border: 0; background: var(--gs-ink); color: var(--gs-white); }
.mobile-menu::backdrop { background: var(--gs-ink); }
.mobile-menu__top { display: flex; align-items: center; justify-content: space-between; font: .8125rem var(--font-mono); padding-bottom: 2rem; border-bottom: 1px solid var(--border); }
.menu-close span { font: 2rem var(--font-sans); }
.mobile-menu nav { display: flex; flex-direction: column; padding-block: 2rem; }
.mobile-menu nav a { font-size: clamp(2rem, 7vw, 3rem); letter-spacing: -.04em; padding-block: 1rem; border-bottom: 1px solid var(--border); }
.mobile-menu p { color: var(--muted-foreground); font-size: .8125rem; padding-block: 1rem; }
@keyframes enter { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }
@keyframes path-arrival { to { stroke-dashoffset: 0; } }
@media (max-width: 1100px) {
  .hero__grid { column-gap: 1.25rem; } h1 { font-size: clamp(3.25rem, 7.1vw, 5rem); }
  .hero__actions { gap: .75rem; } .button { gap: .8rem; }
  .intro__body > p { grid-column: 4 / 8; } .intro__body > div { grid-column: 8 / -1; }
  .footer__main { flex-wrap: wrap; } .footer nav { width: 100%; margin-left: 0; }
  .system__caption > span:first-child { display: none; }
  .system-label text { font-size: 17px; letter-spacing: .5px; }
  .system-label text.system-label--primary { font-size: 19px; }
}
@media (max-width: 900px) {
  :root { --page-gutter: 2rem; }
  .header__inner { min-height: 80px; }
  .has-menu .desktop-nav { display: none; } .has-menu .menu-toggle { display: flex; }
  .desktop-nav { flex-wrap: wrap; gap: .5rem 1rem; } .desktop-nav a:last-child { border: 0; padding-left: 0; }
  .hero { min-height: auto; } .hero__grid { padding-block: 3rem 2rem; }
  h1 { font-size: clamp(3rem, 6.9vw, 4rem); }
  .hero__actions { align-items: flex-start; flex-direction: column; gap: .25rem; }
  .hero__actions .button--secondary { border-color: transparent; padding-left: 0; }
  .hero__actions .button--secondary:hover { background: transparent; color: var(--accent); }
  .system__heading span:last-child { display: none; }
  .system-label text { font-size: 21px; letter-spacing: 0; }
  .system-label text.system-label--primary { font-size: 23px; }
  .intro__heading .eyebrow, h2 { grid-column: 1 / -1; } .intro__heading { gap: 2rem; }
  .intro__body > p { grid-column: 1 / 7; } .intro__body > div { grid-column: 7 / -1; }
  .framework li { padding-inline: 1rem; } .framework__arrow, .framework__end { right: 1rem; } .framework li::before { left: 1rem; }
}
@media (max-width: 700px) {
  :root { --page-gutter: 1.5rem; }
  .header__inner { min-height: 74px; } .brand { width: 90px; height: 66px; } .brand img { width: 96px; height: 96px; left: -3px; top: -13px; }
  .hero__grid { display: flex; flex-direction: column; align-items: stretch; padding-block: 2.5rem 1.5rem; gap: 2rem; }
  .eyebrow { font-size: .75rem; gap: .6rem; letter-spacing: 0; } .label-line { width: 18px; }
  h1 { font-size: clamp(3rem, 12.4vw, 5rem); margin-block: 1.35rem 1.5rem; line-height: 1; }
  .lead { font-size: 1.0625rem; max-width: 33rem; line-height: 1.6; } .hero__actions { margin-top: 1.5rem; gap: .25rem; }
  .button { min-height: 50px; padding-inline: 1rem; gap: 1.75rem; }
  .hero__actions .button--primary { min-width: 14rem; }
  .hero__attribution { margin: -.5rem 0 0; font-size: .75rem; }
  .system { width: 100%; max-width: 460px; margin: 0 auto; }
  .system__heading { padding: .875rem 0; border-top: 1px solid var(--border); border-bottom: none; font-size: .6875rem; }
  .system__heading span:last-child { display: block; }
  .plane--bottom, .plane--middle, .grid-line, .system__caption { display: none; }
  .system__drawing { margin-block: 0; }
  .system-label text { font-size: 23px; }
  .system-label text.system-label--primary { font-size: 26px; }
  .hero__bottom { min-height: 56px; } .hero__bottom > span { display: none; }
  .hero__bottom a { justify-content: space-between; width: 100%; }
  .intro { padding-block: 4rem 4.5rem; } h2 { font-size: clamp(2.5rem, 10.2vw, 3.75rem); max-width: 19ch; text-wrap: pretty; }
  .intro__heading { gap: 1.75rem; }
  .intro__body { grid-template-columns: 1fr; margin-block: 2rem 3rem; gap: 2rem; }
  .intro__body > p, .intro__body > div { grid-column: 1; max-width: 36ch; }
  .intro__body > div { padding: 1.5rem 0 0; border-left: none; border-top: 1px solid var(--border); }
  .intro__body p { font-size: 1.0625rem; }
  h3 { font-size: 1.75rem; margin-bottom: 1rem; } .framework { grid-template-columns: 1fr; }
  .framework li { padding: 1.5rem 0 1.5rem 1rem; display: flex; align-items: center; gap: 1.5rem; font-size: 1.75rem; }
  .framework li + li { border-left: none; border-top: 1px solid var(--border); }
  .framework li::before { top: 0; left: 0; width: 2px; height: 1rem; }
  .framework__number { margin: 0; } .framework__arrow, .framework__end { position: static; margin-left: auto; }
  .framework__arrow { transform: rotate(90deg); }
  .footer { padding-top: 2rem; } .footer__main { gap: 1rem; align-items: center; }
  .footer__main p { max-width: 10rem; line-height: 1.5; } .footer nav { display: grid; grid-template-columns: 1fr 1fr; gap: .5rem 2rem; padding-top: 1rem; }
  .footer__base { flex-direction: column; line-height: 1.6; }
}
/* Keep the skip control out of print/PDF output, including when it had focus. */
@media print { .skip-link, .mobile-menu, .menu-toggle { display: none !important; } }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .activity { stroke-dashoffset: 0; }
}


/* Keep the stacked introduction within narrow phone widths. */
@media (max-width: 700px) { .intro__heading { grid-template-columns: minmax(0, 1fr); } }