:root {
  --bg: #0b1016;
  --bg-elev: #121922;
  --bg-soft: #182231;
  --bg-node: #151d28;
  --line: rgba(230, 236, 245, 0.1);
  --text: #e7edf6;
  --muted: #95a3b8;
  --cyber: #3dd6c6;
  --cyber-dim: rgba(61, 214, 198, 0.12);
  --quant: #f0a35e;
  --quant-dim: rgba(240, 163, 94, 0.12);
  --ai: #c084fc;
  --ai-dim: rgba(192, 132, 252, 0.12);
  --shared: #8ea2ff;
  --ok: #7ddea0;
  --warn: #f0c674;
  --sidebar: 260px;
  --max: 920px;
  --radius: 12px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.04rem;
  line-height: 1.65;
  background:
    radial-gradient(900px 420px at 0% 0%, rgba(61, 214, 198, 0.08), transparent 50%),
    radial-gradient(800px 380px at 100% 0%, rgba(240, 163, 94, 0.07), transparent 45%),
    var(--bg);
  min-height: 100vh;
}

body.page-cyber {
  background:
    radial-gradient(900px 480px at 5% -5%, rgba(61, 214, 198, 0.14), transparent 55%),
    radial-gradient(700px 360px at 100% 10%, rgba(192, 132, 252, 0.08), transparent 50%),
    var(--bg);
}
body.page-quant {
  background:
    radial-gradient(900px 480px at 5% -5%, rgba(240, 163, 94, 0.14), transparent 55%),
    radial-gradient(700px 360px at 100% 10%, rgba(142, 162, 255, 0.08), transparent 50%),
    var(--bg);
}

a { color: var(--cyber); text-underline-offset: 3px; }
body.page-quant a { color: var(--quant); }
a:hover { filter: brightness(1.15); }

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(14px);
  background: rgba(11, 16, 22, 0.82);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0.8rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.74rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
}
.brand strong { color: var(--text); font-weight: 600; }
.top-links { display: flex; flex-wrap: wrap; gap: 0.35rem; }
.top-links a {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--muted);
  padding: 0.4rem 0.7rem;
  border-radius: 999px;
  border: 1px solid transparent;
}
.top-links a:hover,
.top-links a.active {
  color: var(--text);
  border-color: var(--line);
  background: var(--bg-soft);
}
.top-links a.active.cyber { color: var(--cyber); border-color: rgba(61,214,198,0.35); background: var(--cyber-dim); }
.top-links a.active.quant { color: var(--quant); border-color: rgba(240,163,94,0.35); background: var(--quant-dim); }

.layout {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: var(--sidebar) minmax(0, 1fr);
  gap: 0;
  min-height: calc(100vh - 52px);
}
.sidebar {
  position: sticky;
  top: 52px;
  height: calc(100vh - 52px);
  overflow: auto;
  padding: 1.5rem 1rem 2rem 1.25rem;
  border-right: 1px solid var(--line);
  background: rgba(11, 16, 22, 0.55);
}
.sidebar h2 {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.85rem;
  font-weight: 500;
}
.sidebar nav a {
  display: block;
  font-family: "Sora", system-ui, sans-serif;
  font-size: 0.86rem;
  color: var(--muted);
  text-decoration: none;
  padding: 0.4rem 0.55rem;
  border-radius: 8px;
  margin-bottom: 0.15rem;
  line-height: 1.35;
}
.sidebar nav a:hover { color: var(--text); background: var(--bg-soft); }
.sidebar nav a.sub {
  font-size: 0.78rem;
  padding-left: 1.1rem;
  opacity: 0.92;
}
.sidebar .tag {
  display: inline-block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.6rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  margin-left: 0.35rem;
  vertical-align: middle;
}
.tag.ai { background: var(--ai-dim); color: var(--ai); }
.tag.new { background: rgba(125,222,160,0.12); color: var(--ok); }

.content {
  padding: 2.25rem 1.75rem 4rem;
  max-width: calc(var(--max) + 3.5rem);
}
.eyebrow {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.85rem;
}
h1 {
  font-family: "Sora", system-ui, sans-serif;
  font-weight: 700;
  font-size: clamp(1.9rem, 4vw, 2.75rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin: 0 0 0.9rem;
}
.lede {
  color: var(--muted);
  font-size: 1.12rem;
  max-width: 62ch;
  margin: 0 0 1.5rem;
}
.pills { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 2rem; }
.pill {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--line);
}
.pill.cyber { color: var(--cyber); background: var(--cyber-dim); border-color: rgba(61,214,198,0.3); }
.pill.quant { color: var(--quant); background: var(--quant-dim); border-color: rgba(240,163,94,0.3); }
.pill.ai { color: var(--ai); background: var(--ai-dim); border-color: rgba(192,132,252,0.3); }
.pill.shared { color: var(--shared); background: rgba(142,162,255,0.12); border-color: rgba(142,162,255,0.28); }

section.track-section {
  padding: 2rem 0 0.5rem;
  border-top: 1px solid var(--line);
  margin-top: 1.5rem;
}
section.track-section:first-of-type { border-top: 0; margin-top: 0; }
h2 {
  font-family: "Sora", system-ui, sans-serif;
  font-size: 1.45rem;
  letter-spacing: -0.02em;
  margin: 0 0 0.55rem;
}
h3 {
  font-family: "Sora", system-ui, sans-serif;
  font-size: 1.08rem;
  margin: 0 0 0.45rem;
  letter-spacing: -0.01em;
}
h4 {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.65rem;
  font-weight: 500;
}
.section-intro { color: var(--muted); max-width: 68ch; margin: 0 0 1.25rem; }

/* Roadmap path */
.path {
  position: relative;
  display: grid;
  gap: 0.85rem;
  margin: 1rem 0 1.5rem;
  padding-left: 0.35rem;
}
.path::before {
  content: "";
  position: absolute;
  left: 1.05rem;
  top: 0.5rem;
  bottom: 0.5rem;
  width: 2px;
  background: linear-gradient(180deg, var(--line), transparent);
}
body.page-cyber .path::before {
  background: linear-gradient(180deg, rgba(61,214,198,0.45), rgba(192,132,252,0.2), transparent);
}
body.page-quant .path::before {
  background: linear-gradient(180deg, rgba(240,163,94,0.45), rgba(142,162,255,0.2), transparent);
}

.node {
  position: relative;
  margin-left: 2.4rem;
  background: var(--bg-node);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.05rem 1.15rem 1.1rem;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.node:hover {
  border-color: rgba(230, 236, 245, 0.2);
  transform: translateX(2px);
}
.node::before {
  content: "";
  position: absolute;
  left: -1.72rem;
  top: 1.25rem;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--muted);
  z-index: 1;
}
body.page-cyber .node::before { border-color: var(--cyber); box-shadow: 0 0 0 3px var(--cyber-dim); }
body.page-quant .node::before { border-color: var(--quant); box-shadow: 0 0 0 3px var(--quant-dim); }
.node.ai-era::before { border-color: var(--ai); box-shadow: 0 0 0 3px var(--ai-dim); }
.node.skip::before { border-color: var(--ok); }
.node.nested {
  border-style: dashed;
  background: rgba(18, 25, 34, 0.85);
}

.node-head {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.65rem;
  align-items: center;
  margin-bottom: 0.35rem;
}
.node-head h3 { margin: 0; flex: 1 1 auto; }
.badge {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.2rem 0.45rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  white-space: nowrap;
}
.badge.req { color: var(--warn); border-color: rgba(240,198,116,0.35); background: rgba(240,198,116,0.08); }
.badge.lev { color: var(--ok); border-color: rgba(125,222,160,0.3); background: rgba(125,222,160,0.08); }
.badge.ai { color: var(--ai); border-color: rgba(192,132,252,0.35); background: var(--ai-dim); }
.badge.nested-b { color: var(--shared); border-color: rgba(142,162,255,0.3); background: rgba(142,162,255,0.1); }

.node p { margin: 0.35rem 0 0; color: var(--muted); font-size: 0.98rem; }
.node ul {
  margin: 0.55rem 0 0;
  padding-left: 1.15rem;
  color: var(--muted);
}
.node li { margin: 0.28rem 0; }
.node li strong { color: var(--text); font-weight: 600; }

.resources {
  margin-top: 0.85rem;
  padding-top: 0.75rem;
  border-top: 1px dashed var(--line);
}
.resources ul {
  list-style: none;
  padding: 0;
  margin: 0.4rem 0 0;
}
.resources li {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 0.55rem;
  padding: 0.35rem 0;
  font-size: 0.92rem;
}
.resources .rtype {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  padding-top: 0.2rem;
}

.callout {
  padding: 1.1rem 1.2rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--bg-elev);
  margin: 1rem 0 1.5rem;
}
.callout.ai {
  border-color: rgba(192, 132, 252, 0.35);
  background: linear-gradient(135deg, var(--ai-dim), transparent 70%), var(--bg-elev);
}
.callout.cyber {
  border-color: rgba(61, 214, 198, 0.3);
  background: linear-gradient(135deg, var(--cyber-dim), transparent 70%), var(--bg-elev);
}
.callout.quant {
  border-color: rgba(240, 163, 94, 0.3);
  background: linear-gradient(135deg, var(--quant-dim), transparent 70%), var(--bg-elev);
}
.callout h3 { margin-bottom: 0.35rem; }
.callout p { margin: 0; color: var(--muted); }

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
}
.card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.15rem;
}
.card ul { margin: 0.4rem 0 0; padding-left: 1.1rem; color: var(--muted); }
.card li { margin: 0.3rem 0; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
}
th, td {
  text-align: left;
  padding: 0.65rem 0.7rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
th {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 500;
}
td { color: var(--muted); }
td:first-child {
  color: var(--text);
  font-family: "Sora", sans-serif;
  font-weight: 500;
  font-size: 0.92rem;
}

.hub-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 2rem 0;
}
.hub-card {
  display: block;
  text-decoration: none;
  color: inherit;
  padding: 1.5rem 1.4rem;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  transition: transform 0.2s ease, border-color 0.2s ease;
  min-height: 220px;
}
.hub-card:hover { transform: translateY(-3px); }
.hub-card.cyber:hover { border-color: rgba(61,214,198,0.45); }
.hub-card.quant:hover { border-color: rgba(240,163,94,0.45); }
.hub-card h2 {
  font-size: 1.5rem;
  margin: 0.4rem 0 0.6rem;
}
.hub-card p { margin: 0; color: var(--muted); }
.hub-card .arrow {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
  margin-top: 1.25rem;
  color: var(--muted);
}

.checklist label {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  padding: 0.35rem 0;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.95rem;
}
.checklist input { margin-top: 0.35rem; accent-color: var(--cyber); }
body.page-quant .checklist input { accent-color: var(--quant); }

footer.page-foot {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    position: relative;
    top: 0;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    max-height: 220px;
  }
  .content { padding: 1.5rem 1.15rem 3rem; }
  .grid-2, .hub-grid { grid-template-columns: 1fr; }
  .resources li { grid-template-columns: 1fr; gap: 0.15rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}