/* Governed Intelligence — Concept Authority Site
   Design: Architectural, precise, institutional.
   Palette: white bg, charcoal text, gold accent (from deck's Obsidian system), cool secondary */

/* ── Reset & Base ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --color-bg: #FFFFFF;
  --color-bg-alt: #F7F6F3;
  --color-bg-dark: #1C1C1E;
  --color-bg-gold: rgba(184,146,62,0.06);
  --color-bg-cool: rgba(42,111,138,0.04);
  --color-text: #1A1A1A;
  --color-text-secondary: #555555;
  --color-text-tertiary: #8A8A8A;
  --color-text-on-dark: #E8E6E1;
  --color-text-secondary-on-dark: #A0A0A0;
  --color-accent: #B8923E;
  --color-accent-light: #CCA752;
  --color-accent-cool: #2A6F8A;
  --color-accent-warm: #A0522D;
  --color-border: #E0DED8;
  --color-border-light: #ECEAE4;
  --color-border-accent: rgba(184,146,62,0.3);
  --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 740px;
  --max-width-wide: 980px;
}

html { font-size: 16px; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
}

a { color: var(--color-accent-cool); text-decoration: none; }
a:hover { color: var(--color-accent); }

img { max-width: 100%; display: block; }

/* ── Typography ── */
h1 {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin-bottom: 0.75rem;
}

h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: -0.015em;
  margin-bottom: 0.75rem;
}

h3 {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 500;
  line-height: 1.35;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-size: 1.1875rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  max-width: 560px;
}

.label {
  font-family: var(--font-display);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  font-weight: 700;
}

.label-cool {
  font-family: var(--font-display);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent-cool);
  font-weight: 700;
}

/* ── Layout ── */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }
.container-wide { max-width: var(--max-width-wide); margin: 0 auto; padding: 0 1.5rem; }

.section { padding: 5rem 0; }

/* ── Navigation ── */
nav {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--color-border-light);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav .container-wide {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.nav-links { display: flex; gap: 2rem; list-style: none; }
.nav-links a {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  font-weight: 400;
  letter-spacing: 0.01em;
  transition: color 0.15s;
}
.nav-links a:hover { color: var(--color-text); }
.nav-links a.active { color: var(--color-text); font-weight: 500; }

/* ── Hero ── */
.hero {
  padding: 6rem 0 4rem;
  border-bottom: 1px solid var(--color-border-light);
}

/* ── Layer Stack Visual ── */
.layer-stack {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 520px;
  margin: 2rem 0;
}

.layer {
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--color-border);
  position: relative;
}

.layer:first-child { border-radius: 8px 8px 0 0; }
.layer:last-child { border-radius: 0 0 8px 8px; }
.layer + .layer { border-top: none; }

.layer-top {
  background: var(--color-bg-alt);
}

.layer-middle {
  background: var(--color-bg-gold);
  border-color: var(--color-border-accent);
}

.layer-middle + .layer { border-top: none; }

.layer-bottom {
  background: var(--color-bg-cool);
}

.layer-name {
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.layer-desc {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.circuit-breaker-bar {
  padding: 0.5rem 1.5rem;
  background: var(--color-accent);
  color: #fff;
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: center;
}

/* ── Primitive Cards ── */
.primitive-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin: 2rem 0;
}

.primitive-card {
  padding: 1.5rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  border-top: 3px solid var(--color-accent);
}

.primitive-card h3 { margin-bottom: 0.5rem; }
.primitive-card p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.primitive-card .not {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--color-border-light);
  font-style: italic;
}

/* ── Mechanism Steps ── */
.mechanism-flow {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 2rem 0;
}

.mechanism-step {
  padding: 1.25rem;
  background: var(--color-bg-alt);
  border-radius: 6px;
  border-left: 3px solid var(--color-border);
}

.mechanism-step.spine {
  background: var(--color-bg-gold);
  border-left-color: var(--color-accent);
}

.step-num {
  font-family: var(--font-display);
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--color-text-tertiary);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.mechanism-step.spine .step-num { color: var(--color-accent); }

.mechanism-step h4 {
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 500;
  margin-bottom: 0.35rem;
}

.mechanism-step p {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.55;
}

/* ── Bridge Case ── */
.bridge-case {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border-radius: 8px;
  overflow: hidden;
  margin: 2rem 0;
  border: 1px solid var(--color-border);
}

.bridge-left {
  padding: 1.25rem 1.5rem;
  background: var(--color-bg-cool);
  border-right: 1px solid var(--color-border);
}

.bridge-right {
  padding: 1.25rem 1.5rem;
  background: var(--color-bg-gold);
}

/* ── Publication Cards ── */
.pub-list { display: flex; flex-direction: column; gap: 1rem; }

.pub-card {
  padding: 1.25rem 1.5rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: 6px;
  transition: border-color 0.15s;
}
.pub-card:hover { border-color: var(--color-border); }

.pub-card h3 { font-size: 1rem; margin-bottom: 0.35rem; }
.pub-card h3 a { color: var(--color-text); }
.pub-card h3 a:hover { color: var(--color-accent-cool); }

.pub-card p {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.pub-card .authors {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  margin-top: 0.5rem;
}

/* ── Named Concepts ── */
.concept-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.35rem 2rem;
  max-width: 520px;
}

.concept-item {
  font-size: 0.9375rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--color-border-light);
}

/* ── Dark Section ── */
.section-dark {
  background: var(--color-bg-dark);
  color: var(--color-text-on-dark);
  padding: 5rem 0;
}

.section-dark h2 { color: var(--color-text-on-dark); }
.section-dark .subtitle { color: var(--color-text-secondary-on-dark); }
.section-dark .label { color: var(--color-accent); }
.section-dark a { color: var(--color-accent); }
.section-dark a:hover { color: var(--color-accent-light); }

/* ── Highlight Box ── */
.highlight-box {
  padding: 1.5rem;
  border-radius: 6px;
  border-left: 3px solid var(--color-accent);
  background: var(--color-bg-gold);
  margin: 2rem 0;
}

.highlight-box p {
  font-size: 0.9375rem;
  line-height: 1.65;
}

/* ── Footer ── */
footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--color-border-light);
}

footer p {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
}

footer a { color: var(--color-text-tertiary); }
footer a:hover { color: var(--color-text); }

/* ── Responsive ── */
@media (max-width: 680px) {
  h1 { font-size: 1.75rem; }
  .hero { padding: 4rem 0 3rem; }
  .primitive-grid { grid-template-columns: 1fr; }
  .mechanism-flow { grid-template-columns: 1fr; }
  .bridge-case { grid-template-columns: 1fr; }
  .bridge-left { border-right: none; border-bottom: 1px solid var(--color-border); }
  .concept-grid { grid-template-columns: 1fr; }
  .nav-links { gap: 1.25rem; }
  .layer-stack { max-width: 100%; }
}