:root {
  --bg: #08111f;
  --bg-soft: #101c2f;
  --panel: rgba(15, 28, 48, 0.84);
  --panel-strong: rgba(16, 31, 54, 0.96);
  --line: rgba(163, 191, 250, 0.20);
  --text: #e8eefc;
  --muted: #aebbd3;
  --muted-2: #7e8fae;
  --accent: #7dd3fc;
  --accent-2: #a78bfa;
  --accent-3: #38bdf8;
  --warn: #facc15;
  --ok: #86efac;
  --danger: #fca5a5;
  --shadow: 0 22px 70px rgba(0, 0, 0, 0.35);
  --radius: 24px;
  --radius-sm: 14px;
  --max: 1180px;
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 20% 0%, rgba(125, 211, 252, 0.16), transparent 30rem),
    radial-gradient(circle at 80% 12%, rgba(167, 139, 250, 0.16), transparent 26rem),
    linear-gradient(180deg, #07101d 0%, #0b1424 52%, #070d17 100%);
  color: var(--text);
}

button, select, a, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, a:focus-visible, select:focus-visible, input:focus-visible {
  outline: 3px solid rgba(125, 211, 252, 0.8);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 99;
  padding: 0.75rem 1rem;
  background: var(--accent);
  color: #03101f;
  border-radius: 999px;
}
.skip-link:focus { top: 1rem; }

.site-header {
  padding: 4.25rem 1.25rem 2rem;
  border-bottom: 1px solid var(--line);
}
.header-grid {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 390px;
  gap: 2rem;
  align-items: end;
}
.eyebrow {
  margin: 0 0 0.85rem;
  color: var(--accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.78rem;
  font-weight: 700;
}
h1, h2, h3 { margin: 0; line-height: 1.05; }
h1 {
  font-size: clamp(2.75rem, 6.8vw, 6.75rem);
  letter-spacing: -0.07em;
  max-width: 11ch;
}
h2 {
  font-size: clamp(2rem, 4vw, 4rem);
  letter-spacing: -0.05em;
  max-width: 13ch;
}
h3 { font-size: 1.18rem; letter-spacing: -0.02em; }
p { line-height: 1.7; }
.lede {
  max-width: 840px;
  margin: 1.25rem 0 0;
  color: var(--muted);
  font-size: 1.12rem;
}
.hero-actions, .button-row, .paper-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.7rem;
}
.button-row, .paper-controls { margin-top: 0; }
.primary, .secondary, .ghost-link, .chip {
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.82rem 1.1rem;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
}
.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #06101f;
  font-weight: 800;
}
.secondary, .chip {
  background: rgba(255,255,255,0.06);
  color: var(--text);
  border-color: var(--line);
}
.chip.is-active {
  color: #06101f;
  background: var(--accent);
  font-weight: 800;
}
.ghost-link { color: var(--accent); border-color: rgba(125, 211, 252, 0.22); }
.primary:hover, .secondary:hover, .ghost-link:hover, .chip:hover { transform: translateY(-1px); }
.small { padding: 0.5rem 0.75rem; font-size: 0.9rem; }

.control-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1rem;
  backdrop-filter: blur(18px);
}
.control-card__head {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.8rem;
  color: var(--muted);
}
.control-card__head strong { color: var(--text); }
.mode-toggle {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.35rem;
  padding: 0.35rem;
  background: rgba(255,255,255,0.05);
  border-radius: 999px;
}
.mode-btn {
  border: 0;
  border-radius: 999px;
  padding: 0.62rem 0.6rem;
  color: var(--muted);
  background: transparent;
}
.mode-btn.is-active {
  color: #06101f;
  background: var(--accent);
  font-weight: 800;
}
.mode-note { color: var(--muted); margin: 0.85rem 0 0; font-size: 0.93rem; }
.mode-metrics {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.45rem;
}
.mode-metrics span {
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.04);
  border-radius: 999px;
  color: var(--muted);
  padding: 0.5rem 0.7rem;
  font-size: 0.82rem;
}

.tab-shell {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  gap: 0.45rem;
  overflow-x: auto;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  background: rgba(8, 17, 31, 0.86);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--line);
}
.tab {
  flex: 0 0 auto;
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.04);
  color: var(--muted);
  border-radius: 999px;
  padding: 0.62rem 0.9rem;
}
.tab.is-active {
  color: var(--text);
  border-color: rgba(125, 211, 252, 0.55);
  background: rgba(125, 211, 252, 0.10);
}

main { max-width: var(--max); margin: 0 auto; padding: 2rem 1.25rem 4rem; }
.panel { display: none; animation: reveal 240ms ease; }
.panel.is-active { display: block; }
@keyframes reveal { from { opacity: 0; transform: translateY(8px);} to { opacity: 1; transform: translateY(0);} }
.section-heading {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(280px, 1fr);
  gap: 2rem;
  align-items: end;
  margin-bottom: 1.35rem;
}
.section-heading .eyebrow { grid-column: 1 / -1; margin-bottom: -1rem; }
.section-heading p { margin: 0; color: var(--muted); }

.architecture-layout {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr;
  gap: 0.75rem;
  align-items: stretch;
  margin: 1.5rem 0;
}
.flow-card, .content-card, .diagram-card, .interactive-card, .paper-card, .roadmap-card, .deployment-card, .formula-card, .demo-output {
  background: var(--panel-strong);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.flow-card {
  padding: 1.15rem;
  min-height: 210px;
  color: inherit;
  text-align: left;
}
.flow-card:hover, .triad-item:hover { border-color: rgba(125,211,252,0.52); }
.node-index {
  display: inline-flex;
  width: 2.2rem;
  height: 2.2rem;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: rgba(125, 211, 252, 0.12);
  color: var(--accent);
  font-weight: 800;
  margin-bottom: 1rem;
}
.flow-card p { color: var(--muted); margin: 0.85rem 0 1rem; }
.flow-card code, .deployment-card code { color: var(--accent); font-size: 0.82rem; word-break: break-word; }
.flow-arrow { color: var(--muted-2); font-size: 1.6rem; align-self: center; }

.diagram-grid, .split, .evs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1rem;
}
.diagram-card, .content-card, .interactive-card, .paper-card, .deployment-card, .formula-card { padding: 1.25rem; }
.svg-wrap { width: 100%; min-height: 260px; display: grid; place-items: center; margin-top: 1rem; }
svg { width: 100%; height: auto; }
.svg-root { fill: rgba(125, 211, 252, 0.12); stroke: rgba(125, 211, 252, 0.6); stroke-width: 2; }
.svg-proj { fill: rgba(167, 139, 250, 0.13); stroke: rgba(167, 139, 250, 0.65); stroke-width: 2; }
.svg-line { fill: none; stroke: url(#g1); stroke-width: 4; stroke-linecap: round; opacity: 0.72; }
.svg-title { fill: var(--text); font-size: 28px; font-weight: 800; }
.svg-text, .svg-label { fill: var(--muted); font-size: 17px; }
.svg-label { fill: var(--text); font-weight: 700; }
.claim-list { padding-left: 1.1rem; color: var(--muted); line-height: 1.8; }
.claim-list strong { color: var(--text); }
.compact { margin-bottom: 0; }

.content-card p, .interactive-card p, .paper-card p, .roadmap-card p, .deployment-card li { color: var(--muted); }
pre {
  overflow-x: auto;
  padding: 1rem;
  margin: 1rem 0 0;
  border-radius: var(--radius-sm);
  background: rgba(0,0,0,0.25);
  border: 1px solid rgba(255,255,255,0.08);
}
code { font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; color: #c4f1ff; }
.large-code { min-height: 360px; margin-top: 0; }
.highlight { border-color: rgba(125, 211, 252, 0.45); background: rgba(18, 44, 70, 0.78); }
.interactive-head { display: flex; gap: 1rem; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.stackable { align-items: flex-start; }
.tight { margin: 0.35rem 0 0; color: var(--muted); }
.resolver-output { display: grid; gap: 0.65rem; margin-top: 1rem; }
.resolver-row, .inspector-row {
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 0.75rem;
  padding: 0.75rem;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.04);
}
.resolver-row span, .inspector-row span { color: var(--muted-2); }
.resolver-row strong, .inspector-row strong { color: var(--text); word-break: break-word; }
.inspector-output p { color: var(--muted); margin-top: 0; }

.formula-card { margin-bottom: 1rem; background: linear-gradient(135deg, rgba(125,211,252,0.12), rgba(167,139,250,0.08)), var(--panel-strong); }
.formula-label { color: var(--muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.1em; }
.formula { margin: 0.8rem 0; font-size: clamp(2.3rem, 8vw, 5.7rem); letter-spacing: -0.08em; font-weight: 900; }
.fusion-demo, .sim-grid { display: grid; grid-template-columns: 380px 1fr; gap: 1rem; }
.demo-controls {
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  display: grid;
  gap: 0.8rem;
  align-content: start;
}
label { color: var(--muted); display: grid; gap: 0.35rem; }
select, input[type="range"] { width: 100%; }
select {
  background: #0d1a2d;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem;
}
input[type="range"] { accent-color: var(--accent); }
.demo-output { padding: 1.25rem; min-height: 260px; }
.output-pill {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 0.45rem 0.7rem;
  margin-bottom: 0.8rem;
  font-weight: 800;
}
.output-pill.ok { background: rgba(134,239,172,0.16); color: var(--ok); }
.output-pill.warn { background: rgba(250,204,21,0.16); color: var(--warn); }
.output-pill.info { background: rgba(125,211,252,0.16); color: var(--accent); }
.output-pill.danger { background: rgba(252,165,165,0.16); color: var(--danger); }
.demo-output p { color: var(--muted); }
.template-demo { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.template-demo.wide { margin-top: 1rem; }
.triad-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.75rem; margin: 1rem 0; }
.triad-item {
  background: rgba(255,255,255,0.05);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.9rem;
  text-align: left;
  display: grid;
  gap: 0.35rem;
}
.triad-item span { color: var(--muted); font-size: 0.9rem; }
.triad-item.is-active { border-color: rgba(125,211,252,0.62); background: rgba(125,211,252,0.1); }

.metric-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.7rem; margin: 1rem 0; }
.metric {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.85rem;
  background: rgba(255,255,255,0.04);
}
.metric span { color: var(--muted-2); display: block; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; }
.metric strong { display: block; margin-top: 0.4rem; font-size: 1.35rem; }
.heat-bar {
  height: 14px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  overflow: hidden;
  margin-top: 0.7rem;
}
.heat-bar > span { display: block; height: 100%; background: linear-gradient(90deg, var(--ok), var(--warn), var(--danger)); width: 0%; transition: width 180ms ease; }

.paper-card { max-width: 930px; margin: 0 auto; }
.paper-section {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  margin-top: 0.85rem;
  background: rgba(255,255,255,0.035);
  overflow: hidden;
}
.paper-section summary {
  cursor: pointer;
  padding: 1rem;
  font-weight: 800;
  color: var(--text);
}
.paper-section p, .paper-section pre { margin-left: 1rem; margin-right: 1rem; }
.paper-section p:last-child { margin-bottom: 1.2rem; }
.paper-section[hidden] { display: none; }
.copy-note { min-height: 1.5rem; color: var(--ok); margin-top: 0.7rem; }

.roadmap-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.roadmap-card span { color: var(--accent); text-transform: uppercase; font-size: 0.78rem; letter-spacing: 0.12em; font-weight: 800; }
.roadmap-card.is-current { border-color: rgba(125,211,252,0.55); }
.deployment-card { margin-top: 1rem; }
.deployment-card ol { margin-bottom: 0; color: var(--muted); }

.site-footer { max-width: var(--max); margin: 0 auto; padding: 2rem 1.25rem 3rem; color: var(--muted-2); border-top: 1px solid var(--line); }

@media (max-width: 980px) {
  .header-grid, .section-heading, .fusion-demo, .sim-grid, .template-demo, .diagram-grid, .split, .evs-grid { grid-template-columns: 1fr; }
  .architecture-layout { grid-template-columns: 1fr; }
  .flow-arrow { display: none; }
  .roadmap-grid { grid-template-columns: 1fr 1fr; }
  .triad-strip { grid-template-columns: 1fr; }
}
@media (max-width: 620px) {
  .site-header { padding-top: 3rem; }
  .mode-toggle { grid-template-columns: 1fr 1fr; border-radius: var(--radius-sm); }
  .mode-btn { border-radius: var(--radius-sm); }
  .roadmap-grid, .metric-grid { grid-template-columns: 1fr; }
  .resolver-row, .inspector-row { grid-template-columns: 1fr; }
  .hero-actions, .button-row { flex-direction: column; align-items: stretch; }
  .primary, .secondary, .ghost-link, .chip { width: 100%; }
}


/* Part 3 additions */
.compact-row { margin-top: 0.75rem; gap: 0.55rem; }
.ui-demo-grid { display: grid; grid-template-columns: 430px 1fr; gap: 1rem; }
input[type="text"] {
  width: 100%;
  background: #0d1a2d;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.7rem;
}
.event-path, .step-track {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem;
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.04);
}
.path-node, .step-track span {
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.05);
  border-radius: 999px;
  padding: 0.55rem 0.75rem;
  color: var(--muted);
  transition: background 180ms ease, color 180ms ease, border-color 180ms ease, transform 180ms ease;
}
.path-node.is-active, .step-track span.is-active {
  background: rgba(125,211,252,0.16);
  border-color: rgba(125,211,252,0.6);
  color: var(--accent);
  transform: translateY(-1px);
}
.step-track span.is-blocked {
  background: rgba(250,204,21,0.12);
  border-color: rgba(250,204,21,0.5);
  color: var(--warn);
}
.path-arrow { color: var(--muted-2); }
@media (max-width: 980px) { .ui-demo-grid { grid-template-columns: 1fr; } }