/* CORPUS AI LLC — corpus-ai.am
   Design tokens + layout. Dark theme is the base; light theme hooks are declared
   under [data-theme="light"] and prefers-color-scheme so it can be enabled later. */

:root {
  /* colour */
  --bg:              #0b0b0c;
  --bg-sunken:       #0a0a0b;
  --bg-card:         #0d0d0f;
  --bg-input:        #101012;
  --bg-raised:       #17171a;
  --fg:              #ecebe7;
  --fg-secondary:    #a8a6a0;
  --fg-tertiary:     #9a9892;
  --fg-quiet:        #8d8b85;
  --hairline:        #1e1e20;
  --border:          #26262a;
  --border-strong:   #3a3a3d;
  --decor:           #3a3a3d;
  --accent:          #d9a54a;
  --accent-hover:    #f0bf6a;
  --on-accent:       #0b0b0c;

  /* type */
  --font-sans: "Noto Sans", "Noto Sans Armenian", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "Noto Sans Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --fs-mono-xs: 11px;
  --fs-mono-sm: 12px;
  --fs-mono-md: 13px;
  --fs-100: 14px;
  --fs-200: 15px;
  --fs-300: 16px;
  --fs-400: 17px;
  --fs-500: 19px;
  --fs-600: 23px;
  --fs-700: 30px;
  --fs-800: 46px;
  --lh-tight: 1.14;
  --lh-heading: 1.3;
  --lh-body: 1.62;

  /* space */
  --sp-1: 5px;
  --sp-2: 8px;
  --sp-3: 14px;
  --sp-4: 20px;
  --sp-5: 32px;
  --sp-6: 48px;
  --sp-7: 64px;
  --sp-8: 96px;
  --sp-9: 120px;
  --wrap: 1200px;
  --gutter: 32px;

  /* radius / shadow — deliberately flat */
  --radius-0: 0px;
  --radius-1: 2px;
  --shadow-1: 0 1px 0 rgba(255, 255, 255, 0.02);
  --shadow-2: 0 24px 60px rgba(0, 0, 0, 0.55);

  /* motion */
  --dur-1: 150ms;
  --dur-2: 260ms;
  --ease: cubic-bezier(0.32, 0.72, 0.35, 1);
}

[data-theme="light"] {
  --bg: #faf9f6;
  --bg-sunken: #f4f2ee;
  --bg-card: #ffffff;
  --bg-input: #ffffff;
  --bg-raised: #f0eeea;
  --fg: #16161a;
  --fg-secondary: #4b4a46;
  --fg-tertiary: #5e5d58;
  --fg-quiet: #6c6a64;
  --hairline: #e4e1da;
  --border: #d5d2ca;
  --border-strong: #b6b2a9;
  --decor: #c3bfb5;
  --accent: #8a5a10;
  --accent-hover: #6d460b;
  --on-accent: #ffffff;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: var(--fs-300);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

h1, h2, h3 { margin: 0; font-weight: 500; letter-spacing: -0.02em; text-wrap: pretty; }
h1 { font-size: var(--fs-800); line-height: var(--lh-tight); }
h2 { font-size: var(--fs-700); line-height: 1.25; letter-spacing: -0.015em; max-width: 24ch; }
h3 { font-size: var(--fs-500); line-height: var(--lh-heading); letter-spacing: -0.01em; }
p { margin: 0; text-wrap: pretty; }
ul, ol { margin: 0; padding: 0; list-style: none; }

.mono { font-family: var(--font-mono); font-size: var(--fs-mono-sm); letter-spacing: 0.04em; }
.dim { color: var(--fg-tertiary); }
.subtle { color: var(--fg-quiet); }
.subtle:hover { color: var(--accent); }
.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }
.hair { flex: 1; height: 1px; background: var(--hairline); }

.skip {
  position: absolute; left: -9999px; top: 0; z-index: 60;
  background: var(--accent); color: var(--on-accent); padding: 12px 18px; font-size: var(--fs-100);
}
.skip:focus { left: 12px; top: 12px; color: var(--on-accent); }

.grid-bg {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image: radial-gradient(currentColor 0.6px, transparent 0.6px);
  background-size: 30px 30px;
  color: var(--fg);
  opacity: 0.04;
}

/* ---------- header ---------- */

.site-head {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--hairline);
}
.head-row { display: flex; align-items: center; gap: 40px; padding-top: 22px; padding-bottom: 22px; transition: padding var(--dur-1) var(--ease); }
.site-head.condensed .head-row { padding-top: 12px; padding-bottom: 12px; }
.logo { color: var(--fg); font-size: var(--fs-400); font-weight: 600; letter-spacing: -0.01em; }
.nav { display: flex; gap: 26px; font-size: var(--fs-100); margin-left: 16px; }
.nav a { color: var(--fg-secondary); }
.nav a:hover { color: var(--fg); }
.head-right { margin-left: auto; display: flex; align-items: center; gap: var(--sp-4); }
.langs { display: flex; align-items: center; gap: 6px; font-family: var(--font-mono); font-size: var(--fs-mono-sm); }
.langs .lang { color: var(--fg-tertiary); padding: 4px 2px; }
.langs .lang:hover { color: var(--fg); }
.langs .cur { color: var(--fg); }
.langs .sep { color: #5a5a5e; }

.btn { display: inline-flex; align-items: center; justify-content: center; font-size: var(--fs-200); font-weight: 500; padding: 13px 22px; border: 1px solid transparent; cursor: pointer; font-family: inherit; transition: background var(--dur-1) var(--ease), color var(--dur-1) var(--ease), border-color var(--dur-1) var(--ease); }
.btn.solid { background: var(--accent); color: var(--on-accent); }
.btn.solid:hover { background: var(--accent-hover); color: var(--on-accent); }
.btn.ghost { background: var(--bg-raised); color: var(--fg); border-color: var(--border); font-weight: 400; }
.btn.ghost:hover { background: #1f1f23; color: var(--fg); }
.head-cta { padding: 9px 16px; font-size: var(--fs-100); }

.burger { display: none; width: 44px; height: 44px; flex-direction: column; align-items: center; justify-content: center; gap: 5px; background: transparent; border: 1px solid var(--border); cursor: pointer; }
.burger span { width: 18px; height: 1px; background: var(--fg); }
.mobnav { display: none; }

/* ---------- hero ---------- */

.hero { display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr); gap: var(--sp-7); padding-top: 104px; align-items: start; }
.hero-copy { display: flex; flex-direction: column; gap: var(--sp-5); max-width: 660px; }
.eyebrow { font-family: var(--font-mono); font-size: var(--fs-mono-sm); letter-spacing: 0.1em; color: var(--fg-quiet); }
.lead { font-size: var(--fs-400); line-height: 1.6; color: var(--fg-secondary); max-width: 56ch; }
.lead.strong { color: var(--fg); font-size: var(--fs-500); max-width: 60ch; }
.hero-actions { display: flex; align-items: center; gap: var(--sp-4); flex-wrap: wrap; }

.figure { margin: 0; padding-top: 38px; display: flex; flex-direction: column; }
.figure figcaption { font-size: var(--fs-mono-xs); letter-spacing: 0.1em; color: var(--fg-tertiary); padding-bottom: 18px; }
.flow { display: flex; flex-direction: column; }
.node { display: flex; align-items: flex-start; gap: 16px; border: 1px solid #232326; background: var(--bg-card); padding: 16px 18px; }
.node .num { color: var(--fg-quiet); padding-top: 2px; font-size: var(--fs-mono-xs); letter-spacing: 0.04em; }
.node.accent .num { color: var(--accent); }
.node-body { display: flex; flex-direction: column; gap: var(--sp-1); }
.node-title { font-size: var(--fs-100); font-weight: 500; }
.node-meta { font-size: var(--fs-mono-xs); line-height: 1.5; color: var(--fg-quiet); }
.flow .node:not(:last-child) { position: relative; margin-bottom: 22px; }
.flow .node:not(:last-child)::after {
  content: ""; position: absolute; left: 26px; top: 100%; width: 1px; height: 22px;
  background: var(--decor); opacity: 0.5;
}
.flow .node.accent:not(:last-child)::after { background: var(--accent); }

.strip { display: flex; align-items: center; flex-wrap: wrap; gap: 14px; margin-top: var(--sp-8); padding: 16px 0; border-top: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline); color: var(--fg-tertiary); }
.strip li::before { content: "/"; color: #5a5a5e; margin-right: 14px; }
.strip .strip-label { color: var(--fg-quiet); }
.strip .strip-label::before { content: none; margin: 0; }

/* ---------- sections ---------- */

.section { padding-top: var(--sp-9); scroll-margin-top: 80px; }
.section-head { display: flex; align-items: baseline; gap: 18px; padding-bottom: var(--sp-6); }
.section-head .mono { letter-spacing: 0.1em; color: var(--fg-quiet); }
.section h2 { margin-bottom: var(--sp-6); }

.cards { display: grid; gap: 1px; background: var(--hairline); border: 1px solid var(--hairline); }
.cards.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.cards.three { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; background: transparent; border: 0; }
.cards.three .card { border: 1px solid var(--hairline); }
.card { display: flex; flex-direction: column; gap: 16px; background: var(--bg-card); padding: var(--sp-5) var(--sp-5) 30px; }
.card .num { font-size: var(--fs-mono-xs); color: var(--fg-quiet); }
.card p { font-size: var(--fs-200); line-height: var(--lh-body); color: var(--fg-secondary); }
.tags { display: flex; flex-wrap: wrap; gap: var(--sp-2); margin-top: auto; padding-top: var(--sp-3); }
.tags li { font-size: var(--fs-mono-xs); color: var(--fg-quiet); border: 1px solid var(--border); padding: 5px 9px; }
.kv { display: flex; flex-direction: column; gap: 6px; }
.kv .k { font-size: var(--fs-mono-xs); letter-spacing: 0.06em; color: var(--fg-tertiary); }
.kv .v { font-size: var(--fs-100); line-height: 1.6; color: var(--fg-secondary); }

.steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 28px; }
.step { display: flex; flex-direction: column; gap: var(--sp-3); }
.step-rule { display: flex; align-items: center; gap: 10px; }
.step-rule .marker { width: 7px; height: 7px; border: 1px solid var(--decor); }
.step.accent .marker { border-color: var(--accent); }
.step-rule .hair { background: #232326; }
.step-rule .num { font-size: var(--fs-mono-xs); color: var(--fg-quiet); }
.step-title { font-size: var(--fs-300); font-weight: 500; line-height: var(--lh-heading); }
.step-body { font-size: var(--fs-100); line-height: 1.6; color: var(--fg-quiet); }
.note { margin-top: 56px; font-size: var(--fs-300); line-height: 1.65; color: var(--fg-secondary); max-width: 72ch; }

.stack-table { margin: 0; display: flex; flex-direction: column; border-bottom: 1px solid var(--hairline); }
.stack-row { display: grid; grid-template-columns: minmax(0, 0.32fr) minmax(0, 1fr); gap: var(--sp-5); padding: 22px 0; border-top: 1px solid var(--hairline); }
.stack-row dt { font-family: var(--font-mono); font-size: var(--fs-mono-sm); line-height: 1.5; color: var(--fg-quiet); }
.stack-row dd { margin: 0; }
.stack-row ul { display: flex; flex-wrap: wrap; gap: 10px 20px; font-size: var(--fs-200); }

.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 0.68fr); gap: var(--sp-7); align-items: start; }
.split.contact { grid-template-columns: minmax(0, 1fr) minmax(0, 0.62fr); }
.facts { margin: 0; display: grid; grid-template-columns: auto 1fr; gap: var(--sp-3) 24px; font-size: var(--fs-100); }
.facts dt { font-family: var(--font-mono); font-size: var(--fs-mono-sm); color: var(--fg-tertiary); white-space: nowrap; }
.facts dd { margin: 0; }

.mailto-block { display: flex; flex-direction: column; align-items: flex-start; gap: 26px; }
.mailto-block .lead.strong { max-width: 54ch; }
.btn.big { font-size: var(--fs-300); padding: 15px 26px; }
.mailto-note { font-size: var(--fs-mono-xs); line-height: 1.55; max-width: 52ch; }

.aside { display: flex; flex-direction: column; gap: var(--sp-4); border-left: 1px solid var(--hairline); padding-left: 40px; }

/* ---------- documents (privacy / terms) ---------- */

.doc { padding-top: var(--sp-8); padding-bottom: var(--sp-8); display: flex; flex-direction: column; gap: var(--sp-4); }
.doc h1 { font-size: var(--fs-700); max-width: 30ch; }
.prose { display: flex; flex-direction: column; gap: 18px; margin-top: var(--sp-4); }
.prose p { font-size: var(--fs-200); line-height: 1.68; color: var(--fg-secondary); max-width: 70ch; }
.doc-foot { margin-top: var(--sp-6); font-size: var(--fs-mono-sm); }

/* ---------- footer ---------- */

.site-foot { margin-top: 128px; border-top: 1px solid var(--hairline); background: var(--bg-sunken); }
.foot-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) minmax(0, 0.8fr); gap: 40px var(--sp-6); align-items: start; padding-top: var(--sp-6); padding-bottom: 40px; }
.legal-block { font-style: normal; display: flex; flex-direction: column; gap: 7px; font-size: var(--fs-100); line-height: 1.5; }
.legal-block strong { font-size: var(--fs-200); font-weight: 600; }
.legal-block .mono { font-size: var(--fs-mono-md); color: var(--fg-secondary); }
.legal-block span:not(.mono) { color: var(--fg-secondary); }
.foot-links { display: flex; flex-direction: column; gap: 10px; font-size: var(--fs-100); }
.foot-links a { color: var(--fg-secondary); }
.foot-links a:hover { color: var(--fg); }
.foot-links .mono { margin-top: var(--sp-2); }
.foot-meta { display: flex; flex-direction: column; gap: 10px; color: var(--fg-tertiary); }

/* ---------- reveal ---------- */

.reveal { opacity: 0; transform: translateY(14px); transition: opacity var(--dur-2) var(--ease), transform var(--dur-2) var(--ease); }
.reveal.in, .no-js .reveal { opacity: 1; transform: none; }

/* ---------- breakpoints ---------- */

@media (max-width: 1099px) {
  :root { --fs-800: 38px; }
  .hero { grid-template-columns: minmax(0, 1fr); }
  .figure { padding-top: 0; }
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .cards.three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .split, .split.contact { grid-template-columns: minmax(0, 1fr); }
  .aside { border-left: 0; padding-left: 0; }
  .foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 767px) {
  :root { --gutter: 20px; --fs-800: 31px; --fs-700: 23px; --sp-9: 84px; }
  .nav, .head-cta { display: none; }
  .burger { display: flex; }
  .site-head.open .mobnav { display: flex; flex-direction: column; border-top: 1px solid var(--hairline); padding: var(--sp-2) var(--gutter) var(--sp-4); }
  .mobnav a:not(.btn) { color: var(--fg); font-size: var(--fs-400); padding: 14px 0; border-bottom: 1px solid var(--bg-raised); }
  .mobnav .btn { margin-top: 18px; }
  .hero { padding-top: var(--sp-7); gap: var(--sp-6); }
  .cards.two, .cards.three, .steps { grid-template-columns: minmax(0, 1fr); }
  .card { padding: 26px 22px; }
  .stack-row { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .lead.strong { font-size: var(--fs-400); }
  .foot-grid { grid-template-columns: minmax(0, 1fr); }
  .site-foot { margin-top: var(--sp-8); }
}

@media (min-width: 1600px) {
  :root { --wrap: 1320px; --fs-800: 52px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, .reveal { transition: none !important; animation: none !important; opacity: 1 !important; transform: none !important; }
}

@media print {
  .site-head, .grid-bg, .burger, .mobnav { display: none !important; }
  body { background: #fff; color: #000; }
  a { color: #000; }
}