/* =====================================================================
   syseno — deep-tech engineering consultancy
   Identity: instrumentation. Engineering off-white + graph paper, deep
   "scope screen" darks, signal-cyan + sodium-amber accents.
   Type: Space Grotesk (display) / Inter (body) / IBM Plex Mono (telemetry).
   ===================================================================== */

:root {
  --paper:     #f1f4f3;   /* cool engineering off-white */
  --panel:     #e7ecea;   /* graph-paper panel */
  --ink:       #0c1820;   /* deep instrument blue-black */
  --ink-screen:#0a141b;   /* scope-screen dark */
  --ink-soft:  #4f5f5d;
  --line:      #d2dad8;

  --signal:    #12a3b5;   /* signal cyan, accents / borders / button bg */
  --signal-ink:#0a6f7c;   /* darker cyan, accessible as small text on light */
  --signal-br: #2fd2e6;   /* signal cyan, glowing on dark */
  --amber:     #c2741c;   /* sodium / readout amber (accessible on light) */
  --amber-br:  #f0a64c;   /* bright amber, on dark */

  --on-dark:      #e6efee;
  --on-dark-soft: #8ba09e;
  --on-dark-line: rgba(255,255,255,.1);

  --maxw: 1180px;
  --radius: 4px;          /* engineered, near-square */
  --ease: cubic-bezier(.4,.5,.2,1);

  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --display: "Space Grotesk", system-ui, sans-serif;
  --body: "Inter", system-ui, -apple-system, sans-serif;
}

/* ---------- reset ---------- */
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
svg { display: block; }
a { color: inherit; text-decoration: none; }
h1,h2,h3 { font-family: var(--display); font-weight: 600; line-height: 1.02; letter-spacing: -0.02em; }
em { font-style: italic; color: var(--signal-ink); }

.wrap { width: min(100% - 2.5rem, var(--maxw)); margin-inline: auto; }

.skip-link { position: absolute; left: -999px; top: 0; z-index: 200; background: var(--ink); color: var(--on-dark); padding: .6rem 1rem; }
.skip-link:focus { left: 0; }

/* ---------- kicker (mono telemetry label) ---------- */
.kicker {
  font-family: var(--mono); font-size: .76rem; font-weight: 500;
  letter-spacing: .04em; color: var(--signal-ink); margin-bottom: 1.1rem;
}
.kicker--ondark { color: var(--signal-br); }

/* ---------- buttons ---------- */
.btn {
  --py: .85rem; --px: 1.5rem;
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  padding: var(--py) var(--px);
  font-family: var(--mono); font-weight: 500; font-size: .85rem; letter-spacing: .02em;
  border: 1.5px solid transparent; border-radius: var(--radius); cursor: pointer;
  transition: transform .2s var(--ease), background .2s, color .2s, border-color .2s, box-shadow .2s;
  white-space: nowrap;
}
.btn--sm { --py: .55rem; --px: 1rem; font-size: .78rem; }
.btn--lg { --py: 1rem; --px: 1.9rem; font-size: .9rem; }
.btn--solid     { background: var(--ink); color: var(--on-dark); }
.btn--solid:hover { background: var(--signal); color: var(--ink-screen); transform: translateY(-2px); }
.btn--line      { border-color: var(--ink); color: var(--ink); }
.btn--line:hover { background: var(--ink); color: var(--on-dark); }
.btn--linelight { border-color: currentColor; color: inherit; }
.btn--linelight:hover { background: currentColor; transform: translateY(-2px); }
.section--dark .btn--linelight:hover, .hero .btn--linelight:hover { color: var(--ink-screen); }

/* ---------- nav ---------- */
.nav { position: fixed; inset: 0 0 auto 0; z-index: 100; border-bottom: 1px solid transparent; transition: background .3s, border-color .3s; }
.nav.is-stuck { background: rgba(241,244,243,.88); background: color-mix(in srgb, var(--paper) 85%, transparent); -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); border-bottom-color: var(--line); }
.nav__inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.brand { display: inline-flex; align-items: center; gap: .6rem; color: var(--ink); }
.brand__mark { color: var(--signal); }
.brand__name { font-family: var(--display); font-weight: 600; font-size: 1.15rem; letter-spacing: -.01em; }
.nav__links { display: flex; align-items: center; gap: 1.8rem; }
.nav__links a { font-family: var(--mono); font-size: .82rem; color: var(--ink-soft); transition: color .2s; }
.nav__links a:hover { color: var(--ink); }
.nav__links .btn { color: var(--ink); }
.nav__toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; padding: 8px; cursor: pointer; }
.nav__toggle span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; transition: .3s var(--ease); }
.nav.is-open .nav__toggle span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav.is-open .nav__toggle span:nth-child(2) { opacity: 0; }
.nav.is-open .nav__toggle span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- hero (scope screen) ---------- */
.hero { position: relative; background: var(--ink-screen); color: var(--on-dark); padding: clamp(8rem, 15vh, 11rem) 0 clamp(7rem, 12vh, 9.5rem); overflow: hidden; }
.hero::before { /* faint scope grid */
  content: ""; position: absolute; inset: 0; opacity: .5;
  background-image: linear-gradient(var(--on-dark-line) 1px, transparent 1px), linear-gradient(90deg, var(--on-dark-line) 1px, transparent 1px);
  background-size: 46px 46px; mask-image: radial-gradient(120% 90% at 50% 0%, #000 40%, transparent 100%);
}
.scope { position: absolute; left: 0; right: 0; bottom: 0; width: 100%; height: clamp(120px, 14vh, 150px); z-index: 0; opacity: .6; pointer-events: none; }
.scope__trace { fill: none; stroke: var(--signal-br); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; filter: drop-shadow(0 0 6px rgba(47,210,230,.55)); }
.scope__dot { fill: var(--amber-br); filter: drop-shadow(0 0 6px rgba(240,166,76,.8)); }
.hero__inner { position: relative; z-index: 1; }
.hero__title { font-size: clamp(3rem, 9vw, 6.2rem); font-weight: 600; letter-spacing: -.035em; line-height: .97; }
.hero__lede { margin-top: 1.8rem; max-width: 54ch; font-size: clamp(1.05rem, 1.6vw, 1.28rem); color: var(--on-dark-soft); }
.hero__actions { display: flex; flex-wrap: wrap; gap: .9rem; margin-top: 2.4rem; }
.hero .btn--linelight { color: var(--on-dark); }
.telemetry { list-style: none; display: flex; flex-wrap: wrap; gap: 0; margin-top: 3rem; padding-top: 1.6rem; border-top: 1px solid var(--on-dark-line); font-family: var(--mono); font-size: .82rem; color: var(--on-dark); opacity: .82; }
.telemetry li { padding: .2rem 1.3rem; position: relative; }
.telemetry li:not(:first-child)::before { content: ""; position: absolute; left: 0; top: 50%; width: 4px; height: 4px; border-radius: 50%; background: var(--signal-br); transform: translateY(-50%); }
.telemetry li:first-child { padding-left: 0; }

/* ---------- section base ---------- */
.section { padding: clamp(4.5rem, 10vh, 8rem) 0; }
.section--dark { background: var(--ink-screen); color: var(--on-dark); }
.section--grid { position: relative; }
.section--grid::before {
  content: ""; position: absolute; inset: 0; z-index: 0; pointer-events: none; opacity: .55;
  background-image: linear-gradient(rgba(12,24,32,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(12,24,32,.035) 1px, transparent 1px);
  background-size: 46px 46px;
}
.section--grid > .wrap { position: relative; z-index: 1; }
.section__head { max-width: 62ch; margin-bottom: 3.2rem; }
.section__title { font-size: clamp(1.9rem, 4vw, 3.1rem); }
.section__sub { margin-top: 1.1rem; font-size: 1.08rem; color: var(--ink-soft); }
.section__sub--ondark { color: var(--on-dark-soft); }

/* ---------- pipeline / chain ---------- */
.chain { list-style: none; display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; border-top: 1px solid var(--on-dark-line); }
.chain__step { padding: 2rem 1.6rem 0 0; position: relative; }
.chain__step::before { /* node + connecting signal line */
  content: ""; position: absolute; top: -1px; left: 0; width: 10px; height: 10px; border-radius: 50%;
  background: var(--signal-br); box-shadow: 0 0 0 4px rgba(47,210,230,.15); transform: translateY(-50%);
}
.chain__step::after { content: ""; position: absolute; top: -1px; left: 10px; right: 0; height: 1px; background: linear-gradient(90deg, var(--signal-br), transparent); }
.chain__num { font-family: var(--mono); font-size: .8rem; color: var(--amber-br); }
.chain__name { font-size: 1.5rem; margin: 1rem 0 .5rem; }
.chain__step p { color: var(--on-dark-soft); font-size: .96rem; }

/* ---------- capability cards ---------- */
.grid { display: grid; gap: 1.2rem; }
.grid--cards { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.card { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.9rem 1.7rem; position: relative; overflow: hidden; transition: transform .25s var(--ease), border-color .25s, box-shadow .25s; }
.card::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--signal); transform: scaleY(0); transform-origin: top; transition: transform .3s var(--ease); }
.card:hover { transform: translateY(-4px); border-color: var(--signal); box-shadow: 0 22px 44px -26px rgba(12,24,32,.4); }
.card:hover::before { transform: scaleY(1); }
.card__icon { display: inline-flex; align-items: center; justify-content: center; width: 44px; height: 44px; border: 1px solid var(--line); border-radius: var(--radius); color: var(--signal-ink); margin-bottom: 1.1rem; transition: color .25s var(--ease), border-color .25s, background .25s; }
.card__icon svg { width: 22px; height: 22px; }
.card:hover .card__icon { color: var(--signal); border-color: var(--signal); background: color-mix(in srgb, var(--signal) 8%, transparent); }
.card__tag { display: block; font-family: var(--mono); font-size: .76rem; color: var(--signal-ink); letter-spacing: .06em; }
.card__title { font-size: 1.28rem; margin: .7rem 0 .6rem; }
.card p { color: var(--ink-soft); font-size: .97rem; }

/* ---------- rigor band ---------- */
.rigor__inner { display: grid; grid-template-columns: 1.1fr 1fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: center; }
.metrics { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--on-dark-line); border: 1px solid var(--on-dark-line); }
.metric { background: var(--ink-screen); padding: 1.6rem 1.4rem; display: flex; flex-direction: column-reverse; }
.metric__value { font-family: var(--display); font-weight: 600; font-size: clamp(2rem, 4vw, 2.8rem); color: var(--signal-br); line-height: 1; }
.metric__label { font-family: var(--mono); font-size: .82rem; line-height: 1.4; color: var(--on-dark-soft); margin-top: .7rem; }

/* ---------- principles ---------- */
.grid--principles { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.principle { padding: 1.7rem 0 0; border-top: 2px solid var(--ink); }
.principle__title { font-size: 1.2rem; margin-bottom: .5rem; }
.principle p { color: var(--ink-soft); font-size: .97rem; }

/* ---------- pills ---------- */
.grid--pills { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.pill { background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.05rem 1.4rem; font-family: var(--mono); font-size: .85rem; transition: border-color .2s, color .2s, transform .2s; }
.pill:hover { border-color: var(--amber); transform: translateY(-3px); }

/* ---------- quote ---------- */
.quote-section { background: var(--panel); }
.quote { max-width: 56ch; margin-inline: auto; text-align: center; }
.quote blockquote { font-family: var(--display); font-weight: 500; font-size: clamp(1.5rem, 3.4vw, 2.3rem); line-height: 1.28; letter-spacing: -.02em; }
.quote figcaption { font-family: var(--mono); font-size: .78rem; color: var(--ink-soft); margin-top: 1.4rem; }

/* ---------- cta ---------- */
.cta { padding: clamp(4.5rem, 10vh, 8rem) 0; position: relative; overflow: hidden; }
.cta::before { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 50% 58%, rgba(47,210,230,.16), transparent 60%); pointer-events: none; }
.cta__inner { position: relative; text-align: center; max-width: 58ch; margin-inline: auto; }
.cta__title { font-size: clamp(2rem, 4.5vw, 3.3rem); }
.cta__lede { color: var(--on-dark-soft); font-size: 1.1rem; margin: 1.1rem 0 2.2rem; }
.cta__actions { display: flex; flex-wrap: wrap; gap: .9rem; justify-content: center; }
.cta .btn--linelight { color: var(--on-dark); }
.cta__note { font-family: var(--mono); font-size: .74rem; color: var(--on-dark-soft); opacity: .65; margin-top: 1.6rem; }

/* ---------- footer ---------- */
.footer { background: #071015; color: var(--on-dark-soft); padding: 3.4rem 0; }
.footer__inner { display: flex; flex-wrap: wrap; gap: 2rem; justify-content: space-between; align-items: flex-start; }
.footer__brand .brand__name { color: var(--on-dark); }
.footer__brand p { margin-top: .6rem; font-size: .9rem; max-width: 38ch; }
.footer__strap { font-family: var(--mono); font-size: .82rem; color: var(--on-dark-soft); letter-spacing: .02em; }
.footer__strap b { color: var(--signal-br); font-weight: 600; }
.footer__nav { display: flex; gap: 1.5rem; flex-wrap: wrap; font-family: var(--mono); font-size: .82rem; }
.footer__nav a:hover { color: var(--on-dark); }
.footer__legal { width: 100%; border-top: 1px solid var(--on-dark-line); padding-top: 1.4rem; font-family: var(--mono); font-size: .76rem; }

/* ---------- reveal ---------- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .chain { grid-template-columns: 1fr 1fr; }
  .rigor__inner { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .nav__links { position: fixed; inset: 72px 0 auto 0; flex-direction: column; align-items: flex-start; gap: 0; background: var(--paper); border-bottom: 1px solid var(--line); padding: 1rem 1.25rem 1.5rem; transform: translateY(-130%); visibility: hidden; transition: transform .3s var(--ease), visibility .3s; }
  .nav.is-open .nav__links { transform: none; visibility: visible; }
  .nav__links a { width: 100%; padding: .8rem 0; font-size: .95rem; border-bottom: 1px solid var(--line); }
  .nav__links .btn { margin-top: .8rem; width: 100%; }
  .nav__toggle { display: flex; }
  .chain { grid-template-columns: 1fr; }
  .metrics { grid-template-columns: 1fr 1fr; }
}

/* ---------- prefs ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; scroll-behavior: auto !important; }
  .reveal { opacity: 1; transform: none; }
}
:focus-visible { outline: 2px solid var(--signal); outline-offset: 3px; }