/* AI Inferencing Portal — editorial technical design system
   taste-skill redesign: VARIANCE 6 · MOTION 4 · DENSITY 4 */

@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500&family=IBM+Plex+Sans:ital,wght@0,400;0,500;0,600;1,400&family=Newsreader:opsz,wght@6..72,500;6..72,600;6..72,700&display=swap");

:root {
  --bg: #0c1017;
  --bg-panel: #11161f;
  --bg-card: #151b27;
  --bg-elevated: #1a2130;
  --border: #2a3344;
  --border-soft: rgba(232, 236, 244, 0.08);
  --text: #e8ecf4;
  --text-dim: #9aa6ba;
  --text-faint: #6d7689;
  --link: #7eb0e8;
  --accent: #6b9fd4;
  --accent-soft: rgba(107, 159, 212, 0.12);
  --shadow-tint: rgba(20, 40, 70, 0.45);

  --grp-foundation: #6b9fd4;
  --grp-setup: #3db89a;
  --grp-bridge: #d4a04a;

  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, Menlo, monospace;
  --sans: "IBM Plex Sans", "Segoe UI", Helvetica, Arial, sans-serif;
  --display: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;

  --maxw: 46rem;
  --sidebar-w: 17.5rem;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 220ms;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Atmosphere: cool radial wash + grain */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(1200px 700px at 12% -8%, rgba(107, 159, 212, 0.14), transparent 55%),
    radial-gradient(900px 500px at 92% 8%, rgba(61, 184, 154, 0.06), transparent 50%),
    radial-gradient(800px 600px at 70% 100%, rgba(212, 160, 74, 0.05), transparent 55%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.045;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color var(--dur) var(--ease-out);
}
a:hover { text-decoration: underline; text-underline-offset: 3px; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3.5rem;
  z-index: 10000;
  padding: 0.55rem 0.9rem;
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: top var(--dur) var(--ease-out);
}
.skip-link:focus {
  top: 1rem;
  text-decoration: none;
}

/* ---------- Layout ---------- */
.shell {
  position: relative;
  z-index: 1;
  display: flex;
  min-height: 100dvh;
}

.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: color-mix(in srgb, var(--bg-panel) 92%, transparent);
  backdrop-filter: blur(10px);
  border-right: 1px solid var(--border-soft);
  padding: 1.5rem 0 3.75rem;
  position: sticky;
  top: 0;
  height: 100dvh;
  overflow-y: auto;
}

.sidebar-brand {
  padding: 0 1.25rem 1.15rem;
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 0.65rem;
}
.sidebar-brand .kicker {
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 0.3rem;
  font-weight: 500;
}
.sidebar-brand .title {
  font-family: var(--display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.25;
  letter-spacing: -0.015em;
}
.sidebar-brand a.title-link { color: var(--text); }
.sidebar-brand a.title-link:hover {
  text-decoration: none;
  color: var(--link);
}

.nav-group { margin: 1.1rem 0; }
.nav-group-label {
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: 0.85rem 1.25rem 0.4rem;
  font-weight: 500;
}
.nav-item {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  padding: 0.45rem 1.25rem 0.45rem 1rem;
  font-size: 0.84rem;
  color: var(--text-dim);
  border-left: 2px solid transparent;
  transition: background var(--dur) var(--ease-out), color var(--dur) var(--ease-out);
}
.nav-item .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 0.35rem;
  background: var(--text-faint);
}
.nav-item.g-foundation .dot { background: var(--grp-foundation); }
.nav-item.g-setup .dot { background: var(--grp-setup); }
.nav-item.g-bridge .dot { background: var(--grp-bridge); }

.nav-item a { color: inherit; flex: 1; }
.nav-item:hover { color: var(--text); background: rgba(255, 255, 255, 0.03); }
.nav-item.active {
  color: var(--text);
  background: rgba(255, 255, 255, 0.045);
}
.nav-item.active.g-foundation { border-left-color: var(--grp-foundation); }
.nav-item.active.g-setup { border-left-color: var(--grp-setup); }
.nav-item.active.g-bridge { border-left-color: var(--grp-bridge); }

.nav-item.nested { padding-left: 2rem; }
.nav-item.stub { opacity: 0.7; }
.stub-badge {
  font-size: 0.6rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-faint);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 5px;
  white-space: nowrap;
}

.sidebar-footer {
  padding: 1rem 1.25rem 0;
  margin-top: 1.25rem;
  border-top: 1px solid var(--border-soft);
  font-size: 0.75rem;
  color: var(--text-faint);
  line-height: 1.55;
}
.sidebar-footer a { color: var(--text-faint); }

/* ---------- Main content ---------- */
.main {
  flex: 1;
  min-width: 0;
  padding: 3.5rem 2.75rem 6.25rem;
  display: flex;
  justify-content: center;
}
.content {
  width: 100%;
  max-width: var(--maxw);
}

.eyebrow {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 600;
  margin-bottom: 0.7rem;
}
.eyebrow.g-foundation { color: var(--grp-foundation); }
.eyebrow.g-setup { color: var(--grp-setup); }
.eyebrow.g-bridge { color: var(--grp-bridge); }

h1.page-title {
  font-family: var(--display);
  font-size: clamp(2.15rem, 4.2vw, 2.85rem);
  font-weight: 600;
  line-height: 1.12;
  margin: 0 0 0.65rem;
  letter-spacing: -0.025em;
  text-wrap: balance;
}
.page-sub {
  font-size: 1.12rem;
  color: var(--text-dim);
  margin: 0 0 1.75rem;
  max-width: 38rem;
  text-wrap: pretty;
}

.content h2 {
  font-family: var(--display);
  font-size: 1.45rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin: 2.75rem 0 0.9rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border-soft);
  text-wrap: balance;
}
.content h2:first-of-type { border-top: none; padding-top: 0; }
.content h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 1.75rem 0 0.65rem;
  color: var(--text);
}
.content p {
  margin: 0 0 1.05rem;
  color: var(--text);
  text-wrap: pretty;
  max-width: 42rem;
}
.content ul, .content ol {
  margin: 0 0 1.05rem;
  padding-left: 1.35rem;
  max-width: 42rem;
}
.content li { margin-bottom: 0.5rem; }
.content strong { color: #fff; font-weight: 600; }

code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: rgba(255, 255, 255, 0.06);
  padding: 0.1em 0.35em;
  border-radius: 4px;
  color: #e6c07b;
}
pre {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.55;
  margin: 0 0 1.25rem;
  box-shadow: 0 12px 40px var(--shadow-tint);
}
pre code { background: none; padding: 0; color: var(--text-dim); }

/* callouts — editorial rule, less boxy */
.callout {
  border: none;
  border-left: 2px solid var(--border);
  background: color-mix(in srgb, var(--bg-card) 70%, transparent);
  border-radius: 0 8px 8px 0;
  padding: 0.95rem 1.1rem;
  margin: 0 0 1.25rem;
  font-size: 0.95rem;
  max-width: 42rem;
}
.callout .callout-label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  margin-bottom: 0.4rem;
}
.callout.analogy { border-left-color: var(--grp-setup); }
.callout.analogy .callout-label { color: var(--grp-setup); }
.callout.mentalmodel { border-left-color: var(--grp-foundation); }
.callout.mentalmodel .callout-label { color: var(--grp-foundation); }
.callout.networklens { border-left-color: var(--grp-bridge); }
.callout.networklens .callout-label { color: var(--grp-bridge); }
.callout.correction { border-left-color: #d06a7e; }
.callout.correction .callout-label { color: #d06a7e; }
.callout.source { border-left-color: var(--text-faint); }
.callout.source .callout-label { color: var(--text-dim); }
.callout.spotlight {
  border-left-color: #9b87d4;
  background: rgba(155, 135, 212, 0.07);
}
.callout.spotlight .callout-label { color: #9b87d4; }

.content .kicker-label {
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin: 2.5rem 0 0.4rem;
}
.callout p:last-child { margin-bottom: 0; }

/* diagrams */
.diagram-wrap {
  position: relative;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, var(--accent-soft), transparent 65%),
    var(--bg-panel);
  border: 1px solid var(--border-soft);
  border-radius: 14px;
  padding: 1.35rem 1.25rem 1.1rem;
  margin: 0.5rem 0 1.75rem;
  box-shadow: 0 18px 50px var(--shadow-tint);
  overflow: hidden;
}
.diagram-wrap svg { width: 100%; height: auto; display: block; }
.diagram-caption {
  font-size: 0.8rem;
  color: var(--text-faint);
  margin-top: 0.75rem;
  text-align: left;
  line-height: 1.5;
  max-width: 40rem;
}

table.metrics {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin: 0 0 1.4rem;
  font-variant-numeric: tabular-nums;
}
table.metrics th, table.metrics td {
  border: 1px solid var(--border-soft);
  padding: 0.55rem 0.7rem;
  text-align: left;
  vertical-align: top;
}
table.metrics th {
  background: var(--bg-card);
  color: var(--text-dim);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}
table.metrics td.mono {
  font-family: var(--mono);
  color: #e6c07b;
  font-size: 0.8rem;
}

.formula {
  font-family: var(--mono);
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  padding: 1rem 1.25rem;
  text-align: center;
  font-size: 0.95rem;
  color: #e6c07b;
  margin: 0 0 1.4rem;
  box-shadow: 0 10px 30px var(--shadow-tint);
}

.bridge-connector {
  margin-top: 3rem;
  padding: 1rem 1.15rem;
  border-radius: 0 10px 10px 0;
  background: var(--accent-soft);
  border-left: 2px solid var(--link);
  max-width: 42rem;
}
.bridge-connector.closing {
  background: rgba(255, 255, 255, 0.03);
  border-left-color: var(--text-faint);
}
.bridge-label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  color: var(--link);
  margin-bottom: 0.4rem;
}
.bridge-connector.closing .bridge-label { color: var(--text-faint); }
.bridge-connector p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.6;
}
.bridge-connector p a { color: var(--link); }

/* pager */
.pager {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-soft);
}
.pager a {
  flex: 1;
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  color: var(--text);
  background: color-mix(in srgb, var(--bg-card) 80%, transparent);
  transition:
    border-color var(--dur) var(--ease-out),
    transform var(--dur) var(--ease-out),
    background var(--dur) var(--ease-out);
}
.pager a:hover {
  border-color: color-mix(in srgb, var(--accent) 55%, var(--border));
  text-decoration: none;
  transform: translateY(-2px);
  background: var(--bg-elevated);
}
.pager a:active { transform: translateY(0) scale(0.99); }
.pager .dir {
  font-size: 0.68rem;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}
.pager .pager-title {
  font-family: var(--display);
  font-size: 1rem;
  font-weight: 600;
  margin-top: 0.3rem;
  letter-spacing: -0.01em;
}
.pager .next { text-align: right; margin-left: auto; }

.source-note {
  font-size: 0.75rem;
  color: var(--text-faint);
  margin-top: 0.5rem;
}

.badge-stub {
  display: inline-block;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--grp-bridge);
  border: 1px solid color-mix(in srgb, var(--grp-bridge) 55%, transparent);
  border-radius: 4px;
  padding: 0.2rem 0.55rem;
  margin-bottom: 1rem;
  font-weight: 600;
}

details.appendix {
  margin: 2.25rem 0 0.5rem;
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  background: var(--bg-panel);
  padding: 0 1.15rem 0.5rem;
  max-width: 42rem;
}
details.appendix > summary {
  cursor: pointer;
  list-style: none;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-dim);
  padding: 0.9rem 0;
  user-select: none;
}
details.appendix > summary::-webkit-details-marker { display: none; }
details.appendix > summary::before {
  content: "▸ ";
  color: var(--text-faint);
  font-size: 0.75rem;
}
details.appendix[open] > summary::before { content: "▾ "; }
details.appendix[open] > summary {
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 1rem;
  color: var(--text);
}

/* ---------- Landing hero ---------- */
.hero {
  text-align: left;
}

.hero-brand {
  font-family: var(--display);
  font-size: clamp(2.6rem, 6vw, 3.6rem);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 0 0 1rem;
  color: var(--text);
  text-wrap: balance;
  animation: rise-in 0.7s var(--ease-out) both;
}

.hero .page-title {
  font-size: clamp(1.45rem, 2.8vw, 1.85rem);
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
  animation: rise-in 0.7s var(--ease-out) 0.08s both;
}

.hero .page-sub {
  font-size: 1.05rem;
  margin-bottom: 1.35rem;
  animation: rise-in 0.7s var(--ease-out) 0.14s both;
}

.hero-lede {
  animation: rise-in 0.7s var(--ease-out) 0.2s both;
}

.hero-cta {
  margin: 0 0 1.75rem;
  animation: rise-in 0.7s var(--ease-out) 0.22s both;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.7rem 1.15rem;
  background: var(--accent);
  color: #0c1017;
  font-weight: 600;
  font-size: 0.92rem;
  border-radius: 8px;
  border: 1px solid transparent;
  transition:
    transform var(--dur) var(--ease-out),
    background var(--dur) var(--ease-out),
    box-shadow var(--dur) var(--ease-out);
  box-shadow: 0 8px 28px rgba(107, 159, 212, 0.28);
}
.btn-primary:hover {
  background: #7eb0e8;
  text-decoration: none;
  color: #0c1017;
  transform: translateY(-2px);
}
.btn-primary:active { transform: translateY(0) scale(0.98); }

.hero-diagram {
  margin: 2rem 0 0.5rem;
  animation: rise-in 0.85s var(--ease-out) 0.28s both;
}
.hero-diagram .diagram-wrap {
  border-radius: 16px;
  padding: 1.5rem 1.15rem 1.15rem;
  margin-bottom: 0.5rem;
}
.hero-diagram .diagram-wrap > p {
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  font-weight: 600;
  margin: 0 0 0.85rem;
  max-width: none;
}

/* Asymmetric stage strip — replaces equal card grid */
.stage-strip {
  display: grid;
  grid-template-columns: 1.15fr 1fr 1fr;
  gap: 0;
  margin: 2.25rem 0 2.5rem;
  border-top: 1px solid var(--border-soft);
  border-bottom: 1px solid var(--border-soft);
  animation: rise-in 0.8s var(--ease-out) 0.35s both;
}
.stage-item {
  padding: 1.15rem 1.1rem 1.25rem;
  border-right: 1px solid var(--border-soft);
  transition: background var(--dur) var(--ease-out);
}
.stage-item:last-child { border-right: none; }
.stage-item:nth-child(1) { padding-left: 0; }
.stage-item:nth-child(4),
.stage-item:nth-child(5) {
  grid-column: span 1;
}
.stage-item a {
  color: inherit;
  text-decoration: none;
  display: block;
  height: 100%;
}
.stage-item a:hover { text-decoration: none; }
.stage-item:hover { background: rgba(255, 255, 255, 0.025); }
.stage-item .num {
  font-size: 0.68rem;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
}
.stage-item .name {
  font-family: var(--display);
  font-size: 1.2rem;
  font-weight: 600;
  margin: 0.35rem 0 0.45rem;
  letter-spacing: -0.015em;
  color: var(--text);
}
.stage-item p {
  font-size: 0.84rem;
  color: var(--text-dim);
  margin: 0;
  line-height: 1.5;
  max-width: none;
}

/* 5 items: first row 3, second row 2 spanning wider */
.stage-strip {
  grid-template-columns: repeat(6, 1fr);
}
.stage-item { grid-column: span 2; }
.stage-item:nth-child(4) { grid-column: 2 / span 2; }
.stage-item:nth-child(5) {
  grid-column: 4 / span 2;
  border-right: none;
}
.stage-item:nth-child(3) { border-right: none; }

.guide-org {
  margin-top: 0.5rem;
}
.guide-org h2 { margin-top: 1.5rem; }

@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 860px) {
  .sidebar { display: none; }
  .main { padding: 2rem 1.25rem 4rem; }
  .hero-brand { font-size: clamp(2.1rem, 9vw, 2.8rem); }
  .stage-strip {
    grid-template-columns: 1fr;
  }
  .stage-item,
  .stage-item:nth-child(4),
  .stage-item:nth-child(5) {
    grid-column: 1;
    border-right: none;
    border-bottom: 1px solid var(--border-soft);
    padding-left: 0;
    padding-right: 0;
  }
  .stage-item:last-child { border-bottom: none; }
  .pager { flex-direction: column; }
}

/* Legacy stage-card support if any page still uses it */
.stage-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 0.9rem;
  margin: 1.9rem 0;
}
.stage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  color: var(--text);
  transition: border-color var(--dur) var(--ease-out), transform var(--dur) var(--ease-out);
}
.stage-card .num { font-size: 0.68rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.08em; }
.stage-card .name {
  font-family: var(--display);
  font-size: 1rem;
  font-weight: 600;
  margin: 0.3rem 0 0.4rem;
}
.stage-card p { font-size: 0.84rem; color: var(--text-dim); margin: 0; max-width: none; }
.stage-card:hover {
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  transform: translateY(-2px);
}