/* ExI — Experiential Intelligence :: landing styles */

:root {
  --bg: #0a0a0a;
  --bg-1: #101010;
  --bg-2: #161616;
  --ink: #ededea;
  --ink-dim: #a5a59e;
  --ink-mute: #6b6b66;
  --rule: #262624;
  --rule-soft: #1c1c1a;
  --accent-h: 55;
  --accent: oklch(0.78 0.14 var(--accent-h));
  --accent-soft: oklch(0.78 0.14 var(--accent-h) / 0.18);
  --accent-deep: oklch(0.45 0.12 var(--accent-h));
  --ok: oklch(0.78 0.12 150);
  --bad: oklch(0.68 0.18 25);
  --density: 1;

  --f-display: 'Inter Tight', 'Söhne', 'Neue Haas Grotesk', -apple-system, system-ui, sans-serif;
  --f-mono: 'JetBrains Mono', 'Berkeley Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --f-serif: 'IBM Plex Serif', 'Source Serif Pro', Georgia, serif;
}

:root[data-theme="light"] {
  --bg: #f4f1ea;
  --bg-1: #ecece5;
  --bg-2: #e4e4dc;
  --ink: #0a0a0a;
  --ink-dim: #3a3a36;
  --ink-mute: #7a7a70;
  --rule: #d2d1c8;
  --rule-soft: #dedcd3;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

html {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--f-display);
  font-size: 16px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "ss02", "cv11";
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
}

::selection { background: var(--accent); color: #0a0a0a; }

a { color: inherit; text-decoration: none; }

.mono { font-family: var(--f-mono); letter-spacing: -0.01em; }
.serif { font-family: var(--f-serif); font-style: italic; }

.eyebrow {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-mute);
  font-weight: 500;
}

.ink-dim { color: var(--ink-dim); }
.ink-mute { color: var(--ink-mute); }
.accent { color: var(--accent); }

/* ---------- shell ---------- */
.shell {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 40px;
}

@media (max-width: 860px) {
  .shell { padding: 0 20px; }
}

/* ---------- top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.topbar-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 20px;
  padding: 14px 0;
  font-family: var(--f-mono);
  font-size: 12px;
}
.lockup {
  display: inline-grid;
  grid-template-columns: auto auto;
  column-gap: 10px;
  row-gap: 1px;
  align-items: center;
  justify-content: start;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.1;
}
.lockup .mark {
  width: 16px; height: 16px;
  border: 1px solid var(--ink);
  position: relative;
  grid-row: 1 / 3;
  grid-column: 1;
  align-self: center;
}
.lockup .mark::after {
  content: "";
  position: absolute;
  inset: 3px;
  background: var(--accent);
}
.lockup .name { font-weight: 600; grid-column: 2; grid-row: 1; }
.lockup .tag {
  color: var(--ink-mute);
  letter-spacing: 0.06em;
  font-size: 9px;
  font-weight: 500;
  text-transform: uppercase;
  grid-column: 2;
  grid-row: 2;
  border: none;
  padding: 0;
  font-family: inherit;
  border-radius: 0;
}
.topnav {
  display: flex;
  gap: 28px;
  justify-self: center;
  color: var(--ink-dim);
  flex-wrap: nowrap;
  white-space: nowrap;
  align-items: center;
}
@media (max-width: 1180px) {
  .topnav { gap: 18px; font-size: 12px; }
}
@media (max-width: 1020px) {
  .topnav { display: none; }
}

/* dropdown groups */
.nav-group { position: relative; }
.nav-trigger {
  background: transparent;
  border: 0;
  padding: 0;
  margin: 0;
  font: inherit;
  color: inherit;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  letter-spacing: inherit;
}
.nav-trigger:hover,
.nav-group:hover .nav-trigger,
.nav-group:focus-within .nav-trigger { color: var(--ink); }
.nav-chev {
  width: 7px;
  height: 7px;
  border-right: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
  transform: rotate(45deg) translateY(-1px);
  transition: transform 0.15s ease;
  display: inline-block;
  opacity: 0.7;
}
.nav-group:hover .nav-chev,
.nav-group:focus-within .nav-chev { transform: rotate(225deg) translateY(-1px); opacity: 1; }
.nav-menu {
  position: absolute;
  top: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  background: var(--bg);
  border: 1px solid var(--rule);
  display: flex;
  flex-direction: column;
  min-width: 200px;
  padding: 6px 0;
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
  transition: opacity 0.12s ease, transform 0.12s ease, visibility 0.12s;
  z-index: 60;
  box-shadow: 0 12px 32px -16px color-mix(in oklab, var(--ink) 18%, transparent);
}
.nav-group:hover .nav-menu,
.nav-group:focus-within .nav-menu {
  opacity: 1;
  pointer-events: auto;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.nav-menu::before {
  content: "";
  position: absolute;
  top: -10px;
  left: 0;
  right: 0;
  height: 10px;
}
.nav-menu a {
  padding: 9px 16px;
  font-size: inherit;
  color: var(--ink-dim);
  white-space: nowrap;
  letter-spacing: inherit;
}
.nav-menu a:hover,
.nav-menu a:focus-visible { color: var(--ink); background: var(--bg-1); }
.topnav a:hover { color: var(--ink); }
.topright { display: flex; gap: 14px; align-items: center; color: var(--ink-dim); }
.topright .pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-size: 11px;
}
.topright .pill .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--ok);
  box-shadow: 0 0 10px var(--ok);
}
.cta-link {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
  padding-bottom: 2px;
}

/* ---------- section scaffolding ---------- */
section {
  border-top: 1px solid var(--rule);
  padding: calc(96px * var(--density)) 0;
  position: relative;
}
section.no-rule { border-top: none; }
.sect-head {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 40px;
  margin-bottom: 56px;
}
.sect-head .idx {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-mute);
  padding-top: 10px;
  border-top: 1px solid var(--ink);
  align-self: start;
}
.sect-head h2 {
  font-family: var(--f-display);
  font-size: clamp(32px, 3.6vw, 54px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  margin: 0;
  font-weight: 500;
  max-width: 22ch;
  text-wrap: balance;
}
.sect-head h2 em {
  font-family: var(--f-serif);
  font-weight: 400;
  font-style: italic;
  color: var(--ink-dim);
}

@media (max-width: 860px) {
  .sect-head { grid-template-columns: 1fr; gap: 16px; margin-bottom: 32px; }
  section { padding: 64px 0; }
}

.cols-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.cols-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.cols-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
@media (max-width: 980px) {
  .cols-2, .cols-3, .cols-4 { grid-template-columns: 1fr; gap: 24px; }
}

.prose { max-width: 68ch; color: var(--ink-dim); font-size: 17px; line-height: 1.6; }
.prose strong { color: var(--ink); font-weight: 600; }
.prose p + p { margin-top: 1em; }

/* ---------- hero ---------- */
.hero {
  padding-top: 80px;
  padding-bottom: 120px;
  border-top: none;
  position: relative;
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 72px;
  align-items: end;
}
@media (max-width: 1040px) {
  .hero-grid { grid-template-columns: 1fr; }
}
.hero h1 {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(48px, 7.8vw, 118px);
  line-height: 0.92;
  letter-spacing: -0.035em;
  margin: 0 0 28px;
  text-wrap: balance;
}
.hero h1 em {
  font-family: var(--f-serif);
  font-style: italic;
  font-weight: 400;
  color: var(--ink-dim);
  display: block;
}
.hero h1 .mark-line {
  display: inline-block;
  width: 0.9em;
  height: 0.08em;
  background: var(--accent);
  vertical-align: middle;
  margin-right: 0.18em;
  transform: translateY(-0.1em);
}
.hero-sub {
  font-size: 20px;
  line-height: 1.45;
  color: var(--ink-dim);
  max-width: 44ch;
  margin: 0 0 28px;
  text-wrap: pretty;
}
.hero-meta {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
  color: var(--ink-mute);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
}
.hero-meta b { color: var(--ink); font-weight: 600; }
.hero-cta { display: flex; gap: 12px; margin-top: 20px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 18px;
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: 0.01em;
  border: 1px solid var(--ink);
  border-radius: 2px;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  transition: all 0.15s ease;
}
.btn:hover { background: var(--ink); color: var(--bg); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #0a0a0a; }
.btn.primary:hover { background: oklch(0.82 0.14 var(--accent-h)); border-color: oklch(0.82 0.14 var(--accent-h)); }
.btn .arr { transition: transform 0.2s; }
.btn:hover .arr { transform: translateX(3px); }

.hero-side {
  position: relative;
}

/* ---------- utility cards ---------- */
.card {
  border: 1px solid var(--rule);
  padding: 24px;
  background: var(--bg-1);
  position: relative;
}
.card-label {
  font-family: var(--f-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 14px;
  display: flex;
  justify-content: space-between;
}
.card h3 {
  font-family: var(--f-display);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
  line-height: 1.2;
}
.card p { margin: 0; color: var(--ink-dim); font-size: 14.5px; line-height: 1.55; }

/* ---------- math blocks ---------- */
.eq {
  font-family: var(--f-serif);
  font-style: italic;
  font-size: 22px;
  line-height: 1.4;
  color: var(--ink);
  padding: 20px 24px;
  border-left: 2px solid var(--accent);
  background: var(--bg-1);
  overflow-x: auto;
  white-space: nowrap;
}
.eq .sub { font-size: 0.62em; vertical-align: sub; }
.eq .sup { font-size: 0.62em; vertical-align: super; }
.eq .op { font-family: var(--f-display); font-style: normal; padding: 0 6px; color: var(--ink-dim); }
.eq .fn { font-family: var(--f-display); font-style: italic; }

/* ---------- scrollbar ---------- */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--rule); }
::-webkit-scrollbar-thumb:hover { background: var(--ink-mute); }

/* ---------- diagram primitives ---------- */
.diagram {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--rule);
  background:
    linear-gradient(var(--rule-soft) 1px, transparent 1px) 0 0 / 100% 40px,
    linear-gradient(90deg, var(--rule-soft) 1px, transparent 1px) 0 0 / 40px 100%,
    var(--bg-1);
}
.caption {
  display: flex;
  justify-content: space-between;
  font-family: var(--f-mono);
  font-size: 11px;
  color: var(--ink-mute);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--rule);
}

/* ---------- tag ---------- */
.tag-row { display: flex; gap: 8px; flex-wrap: wrap; }
.tag {
  font-family: var(--f-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  padding: 4px 8px;
  border: 1px solid var(--rule);
  color: var(--ink-dim);
  text-transform: uppercase;
  border-radius: 2px;
}
.tag.on { border-color: var(--accent); color: var(--accent); }
.tag.ok { border-color: var(--ok); color: var(--ok); }
.tag.bad { border-color: var(--bad); color: var(--bad); }

/* ---------- comparison table ---------- */
table.compare {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
table.compare th, table.compare td {
  text-align: left;
  padding: 16px 16px;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
table.compare th {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-mute);
  font-weight: 500;
  padding-bottom: 10px;
  padding-top: 0;
}
table.compare td:first-child {
  font-weight: 500;
  color: var(--ink);
  font-family: var(--f-mono);
  font-size: 12.5px;
  letter-spacing: 0.02em;
  width: 22%;
}
table.compare td.bad { color: var(--ink-mute); }
table.compare td.good { color: var(--ink); }
table.compare td.good::before {
  content: "✓  "; color: var(--accent); font-family: var(--f-mono);
}
table.compare td.bad::before {
  content: "—  "; color: var(--ink-mute); font-family: var(--f-mono);
}

/* ---------- terminal ---------- */
.terminal {
  background: #050505;
  border: 1px solid var(--rule);
  font-family: var(--f-mono);
  font-size: 12.5px;
  line-height: 1.7;
  color: #d0d0c8;
  padding: 18px 20px;
  overflow-x: auto;
  white-space: pre;
}
:root[data-theme="light"] .terminal { background: #1b1b18; color: #e8e6df; }
.terminal .c-key { color: oklch(0.78 0.14 var(--accent-h)); }
.terminal .c-str { color: oklch(0.78 0.1 150); }
.terminal .c-num { color: oklch(0.78 0.13 230); }
.terminal .c-fn { color: #ededea; }
.terminal .c-mute { color: #6b6b66; }
.terminal .c-bad { color: oklch(0.72 0.2 25); }
.terminal .c-ok { color: oklch(0.78 0.14 150); }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--rule);
  padding: 72px 0 48px;
  font-family: var(--f-mono);
  font-size: 12px;
  color: var(--ink-mute);
}
.foot-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 56px;
}
@media (max-width: 860px) { .foot-grid { grid-template-columns: 1fr 1fr; } }
.foot-col h5 {
  color: var(--ink-dim);
  font-weight: 500;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin: 0 0 18px;
}
.foot-col ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.foot-col a { color: var(--ink-dim); }
.foot-col a:hover { color: var(--ink); }
.foot-bottom {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px;
  border-top: 1px solid var(--rule);
  padding-top: 20px;
}

/* ---------- tweaks panel ---------- */
.tweaks-panel {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 60;
  width: 300px;
  background: var(--bg-1);
  border: 1px solid var(--rule);
  padding: 18px;
  font-family: var(--f-mono);
  font-size: 11px;
  color: var(--ink-dim);
  display: none;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
}
.tweaks-panel.on { display: block; }
.tweaks-panel h6 {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink);
  display: flex;
  justify-content: space-between;
}
.tweaks-panel label {
  display: block;
  margin-bottom: 14px;
}
.tweaks-panel label span {
  display: flex; justify-content: space-between;
  margin-bottom: 6px;
  color: var(--ink-mute);
}
.tweaks-panel label span b { color: var(--ink); }
.tweaks-panel input[type=range] {
  width: 100%; accent-color: var(--accent);
}
.tweaks-panel .seg {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--rule);
}
.tweaks-panel .seg button {
  background: transparent;
  color: var(--ink-dim);
  border: none;
  padding: 8px;
  font-family: var(--f-mono);
  font-size: 11px;
  cursor: pointer;
  letter-spacing: 0.08em;
}
.tweaks-panel .seg button.on {
  background: var(--ink);
  color: var(--bg);
}

/* ---------- misc ---------- */
.rule { border-top: 1px solid var(--rule); margin: 32px 0; }
.kv {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 8px 18px;
  font-family: var(--f-mono);
  font-size: 12.5px;
}
.kv dt { color: var(--ink-mute); }
.kv dd { margin: 0; color: var(--ink); }

.fade-in {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.fade-in.in { opacity: 1; transform: translateY(0); }

/* spec figure frame */
.fig {
  border: 1px solid var(--rule);
  background: var(--bg-1);
  padding: 24px;
  position: relative;
}
.fig::before {
  content: attr(data-fig);
  position: absolute;
  top: -1px; left: -1px;
  background: var(--bg);
  color: var(--ink-mute);
  font-family: var(--f-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 6px 10px;
  border: 1px solid var(--rule);
  border-top: none;
  border-left: none;
}