/* ==========================================================================
   Christian Superintelligence (christiansuperintelligence.org)
   A Faithful Order initiative | Sibling design system
   ========================================================================== */

:root {
  --bg-paper: #FAF7F2;
  --bg-vellum: #F3EFE6;
  --bg-card: #FFFEFC;
  --bg-deep: #17191C;
  --bg-deep-elevated: #212429;

  --ink-primary: #17191C;
  --ink-secondary: #3C3A36;
  --ink-muted: #656056;
  --ink-faint: #8A8377;

  --accent-oxblood: #6E2420;
  --accent-oxblood-soft: #F5ECEB;
  --accent-brass: #8F6F40;
  --accent-brass-light: #D4B483;
  --accent-brass-bright: #E8CFA5;

  --rule-strong: #17191C;
  --rule-medium: #C9BFB0;
  --rule-hairline: #DFD7CA;
  --rule-deep: #2E3239;

  --font-serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --max-width: 1140px;
  --reading-width: 720px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--bg-paper);
  color: var(--ink-primary);
}

body {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 1.125rem;
  line-height: 1.72;
  background-color: var(--bg-paper);
  color: var(--ink-primary);
}

a {
  color: var(--accent-oxblood);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
}

a:hover {
  color: var(--ink-primary);
}

p {
  margin: 0 0 1.25rem;
}

p:last-child {
  margin-bottom: 0;
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.2;
  color: var(--ink-primary);
  margin: 0;
  letter-spacing: -0.015em;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--bg-paper);
  color: var(--ink-primary);
  padding: 0.6rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  z-index: 999;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

/* ==========================================================================
   Top Bar & Header (Deep Ink Sibling Styling)
   ========================================================================== */

.top-ledger {
  background-color: #111316;
  border-bottom: 1px solid #262A31;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #B4AEA3;
}

.top-ledger-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.55rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.top-ledger a {
  color: var(--accent-brass-light);
  text-decoration: none;
}

.top-ledger a:hover {
  color: var(--bg-paper);
  text-decoration: underline;
}

.top-ledger-verse {
  font-family: var(--font-serif);
  font-style: italic;
  text-transform: none;
  letter-spacing: 0.01em;
  font-size: 0.88rem;
  color: #CFC9BE;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(23, 25, 28, 0.96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule-deep);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.95rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  color: var(--bg-paper);
}

.brand:hover {
  color: var(--bg-paper);
}

.brand-mark {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.1;
  color: var(--bg-paper);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-brass-light);
  margin-top: 0.2rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 0.86rem;
  font-weight: 500;
  color: #D2CCC2;
  text-decoration: none;
  padding: 0.45rem 0.8rem;
  border-radius: 3px;
  transition: color 0.15s ease, background-color 0.15s ease;
}

.nav-link:hover {
  color: var(--bg-paper);
  background-color: var(--bg-deep-elevated);
}

.nav-link[aria-current="page"] {
  color: var(--accent-brass-bright);
  background-color: rgba(212, 180, 131, 0.12);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid #3C414B;
  padding: 0.45rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--bg-paper);
  cursor: pointer;
}

/* ==========================================================================
   Layout & Sections
   ========================================================================== */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.prose-narrow {
  max-width: var(--reading-width);
}

.section {
  padding: 4.5rem 0;
  border-bottom: 1px solid var(--rule-hairline);
}

.section-vellum {
  background-color: var(--bg-vellum);
}

.section-deep {
  background-color: var(--bg-deep);
  color: var(--bg-paper);
  border-bottom: 1px solid var(--rule-deep);
}

.section-deep h1,
.section-deep h2,
.section-deep h3,
.section-deep h4 {
  color: var(--bg-paper);
}

.section-deep p {
  color: #D4CFC6;
}

.section-deep a:not(.btn) {
  color: var(--accent-brass-light);
}

.section-deep a:not(.btn):hover {
  color: #FFFFFF;
}

.section-title {
  font-size: clamp(1.85rem, 3vw, 2.45rem);
  margin-bottom: 1.15rem;
}

.section-lead {
  font-size: 1.2rem;
  color: var(--ink-secondary);
  line-height: 1.68;
  max-width: 740px;
}

.section-deep .section-lead {
  color: #D4CFC6;
}

/* ==========================================================================
   Home Hero (Deep Ink + Ordered Network Diagram)
   ========================================================================== */

.hero-deep {
  background-color: var(--bg-deep);
  color: var(--bg-paper);
  padding: 4.75rem 0 4.5rem;
  border-bottom: 1px solid var(--rule-deep);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.9fr);
  gap: 3.5rem;
  align-items: center;
}

.hero-eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.73rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-brass-light);
  margin-bottom: 1rem;
}

.hero-title {
  font-size: clamp(2.35rem, 4.4vw, 3.55rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--bg-paper);
  margin-bottom: 1.35rem;
}

.hero-title em {
  font-style: italic;
  color: var(--accent-brass-light);
}

.hero-lede {
  font-size: 1.22rem;
  line-height: 1.65;
  color: #DDD7CD;
  margin-bottom: 2rem;
  max-width: 640px;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  font-weight: 500;
  text-decoration: none;
  padding: 0.74rem 1.3rem;
  border-radius: 2px;
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.btn-brass {
  background-color: var(--accent-brass-light);
  color: var(--ink-primary);
  border-color: var(--accent-brass-light);
}

.btn-brass:hover {
  background-color: var(--accent-brass-bright);
  border-color: var(--accent-brass-bright);
  color: var(--ink-primary);
}

.btn-ghost-dark {
  background-color: transparent;
  color: var(--bg-paper);
  border-color: #464B55;
}

.btn-ghost-dark:hover {
  border-color: var(--accent-brass-light);
  color: var(--accent-brass-bright);
}

.btn-primary {
  background-color: var(--ink-primary);
  color: var(--bg-paper);
  border-color: var(--ink-primary);
}

.btn-primary:hover {
  background-color: var(--accent-oxblood);
  border-color: var(--accent-oxblood);
  color: var(--bg-paper);
}

.btn-secondary {
  background-color: var(--bg-card);
  color: var(--ink-primary);
  border-color: var(--rule-medium);
}

.btn-secondary:hover {
  border-color: var(--ink-primary);
  background-color: var(--bg-vellum);
}

.diagram-panel {
  background-color: var(--bg-deep-elevated);
  border: 1px solid #323741;
  padding: 1.5rem;
}

.diagram-panel svg {
  width: 100%;
  height: auto;
  display: block;
}

.diagram-caption {
  margin-top: 0.95rem;
  padding-top: 0.85rem;
  border-top: 1px solid #2F343D;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  line-height: 1.5;
  color: #B4AEA3;
}

/* ==========================================================================
   Three Research Program Cards
   ========================================================================== */

.programs-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.program-card {
  background-color: var(--bg-deep-elevated);
  border: 1px solid #32363E;
  border-top: 2px solid var(--accent-brass);
  padding: 1.85rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.program-card h3 {
  font-size: 1.38rem;
  margin-bottom: 0.85rem;
  color: var(--bg-paper);
}

.program-card p {
  font-size: 1rem;
  line-height: 1.65;
  color: #CFC9BE;
  margin-bottom: 1.4rem;
}

.program-link {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--accent-brass-light);
  text-decoration: none;
}

.program-link:hover {
  color: #FFFFFF;
  text-decoration: underline;
}

/* ==========================================================================
   Subpage Headers & Prose Shell
   ========================================================================== */

.page-hero {
  background-color: var(--bg-deep);
  color: var(--bg-paper);
  padding: 3.75rem 0 3rem;
  border-bottom: 1px solid var(--rule-deep);
}

.page-hero h1 {
  color: var(--bg-paper);
  font-size: clamp(2.1rem, 4vw, 3.05rem);
  max-width: 820px;
  margin-bottom: 0.95rem;
}

.page-hero-sub {
  font-size: 1.2rem;
  line-height: 1.62;
  color: #D4CFC6;
  max-width: 760px;
  margin: 0;
}

.doc-shell {
  display: grid;
  grid-template-columns: 235px minmax(0, 1fr);
  gap: 3.5rem;
  padding: 3.5rem 0 5rem;
  align-items: start;
}

.doc-toc {
  position: sticky;
  top: 5.5rem;
  border-left: 1px solid var(--rule-medium);
  padding-left: 1.1rem;
}

.doc-toc-title {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 0.8rem;
}

.doc-toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.doc-toc a {
  font-family: var(--font-sans);
  font-size: 0.84rem;
  line-height: 1.38;
  color: var(--ink-secondary);
  text-decoration: none;
  display: block;
}

.doc-toc a:hover,
.doc-toc a.is-active {
  color: var(--accent-oxblood);
  font-weight: 600;
}

.doc-prose {
  max-width: var(--reading-width);
}

.doc-section {
  padding-bottom: 2.75rem;
  margin-bottom: 2.75rem;
  border-bottom: 1px solid var(--rule-hairline);
  scroll-margin-top: 6rem;
}

.doc-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.doc-section h2 {
  font-size: 1.82rem;
  margin-bottom: 1.05rem;
}

.doc-section h3 {
  font-size: 1.3rem;
  margin-top: 1.75rem;
  margin-bottom: 0.6rem;
}

.prose-list {
  padding-left: 1.25rem;
  margin: 1rem 0 1.25rem;
}

.prose-list li {
  margin-bottom: 0.75rem;
}

.callout-note {
  background-color: var(--bg-vellum);
  border-left: 3px solid var(--accent-brass);
  padding: 1.2rem 1.45rem;
  margin: 1.6rem 0;
  color: var(--ink-secondary);
}

.inline-figure {
  background-color: var(--bg-deep);
  border: 1px solid var(--rule-deep);
  padding: 1.4rem;
  margin: 1.75rem 0;
}

.inline-figure svg {
  width: 100%;
  height: auto;
  display: block;
}

.inline-figure figcaption {
  margin-top: 0.85rem;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: #B4AEA3;
  line-height: 1.5;
}

.contact-card {
  background-color: var(--bg-card);
  border: 1px solid var(--rule-medium);
  padding: 2rem;
  max-width: 680px;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  background-color: var(--bg-deep);
  color: #CFC9BE;
  border-top: 1px solid var(--rule-deep);
  padding: 3.5rem 0 2.5rem;
  font-size: 0.96rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr) minmax(0, 1fr);
  gap: 2.5rem;
  padding-bottom: 2.25rem;
  border-bottom: 1px solid var(--rule-deep);
}

.footer-descriptor {
  font-size: 1rem;
  line-height: 1.62;
  color: #D4CFC6;
  max-width: 500px;
  margin-top: 0.85rem;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-brass-light);
  margin-bottom: 0.85rem;
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}

.footer-links a {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  color: #D2CCC2;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--accent-brass-bright);
  text-decoration: underline;
}

.footer-bottom {
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-family: var(--font-mono);
  font-size: 0.73rem;
  color: #9E988E;
}

/* ==========================================================================
   Responsive & Print
   ========================================================================== */

@media (max-width: 960px) {
  .hero-grid,
  .programs-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .doc-shell {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .doc-toc {
    position: static;
    border-left: none;
    border-top: 1px solid var(--rule-medium);
    border-bottom: 1px solid var(--rule-medium);
    padding: 1rem 0;
  }
}

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-block;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--bg-deep);
    border-bottom: 1px solid var(--rule-deep);
    padding: 0.85rem 1.5rem 1.15rem;
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav.is-open {
    display: flex;
  }

  .top-ledger-inner {
    justify-content: center;
    text-align: center;
  }
}

@media print {
  .top-ledger,
  .site-nav,
  .nav-toggle,
  .doc-toc,
  .cta-row,
  .site-footer {
    display: none !important;
  }

  body {
    background: #FFFFFF;
    color: #000000;
    font-size: 11pt;
  }

  .page-hero,
  .hero-deep {
    background: #FFFFFF;
    color: #000000;
  }

  .page-hero h1,
  .hero-title {
    color: #000000;
  }
}