@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,300;0,400;0,500;0,600;1,300;1,400&family=Rajdhani:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg: #06050e;
  --bg-deep: #040310;
  --bg-panel: rgba(20, 16, 42, 0.55);
  --bg-panel-solid: #120f26;
  --bg-glow: rgba(212, 168, 83, 0.06);
  --fg: #f1ede0;
  --fg-mid: #bcb6a4;
  --fg-dim: #827a67;
  --accent: #d4a853;
  --accent-bright: #f0e0b8;
  --accent-deep: #7a5e2a;
  --accent-glow: rgba(212, 168, 83, 0.35);
  --proved: #8dffb8;
  --empirical: #a8c6ff;
  --conjectural: #f5d26b;
  --rejected: #ff8a68;
  --divider: rgba(212, 168, 83, 0.18);
  --divider-soft: rgba(212, 168, 83, 0.08);
  --serif: 'Cormorant Garamond', Georgia, serif;
  --sans: 'Rajdhani', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'JetBrains Mono', SFMono-Regular, Menlo, monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { min-height: 100vh; background: var(--bg-deep); }
body {
  font-family: var(--sans);
  font-weight: 300;
  color: var(--fg);
  line-height: 1.6;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
  overflow-x: hidden;
}

/* ---- Background layers ---- */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -3;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(120, 80, 180, 0.18) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 20% 100%, rgba(30, 180, 160, 0.10) 0%, transparent 70%),
    radial-gradient(ellipse 70% 50% at 80% 80%, rgba(212, 168, 83, 0.08) 0%, transparent 60%),
    linear-gradient(180deg, var(--bg-deep) 0%, #0a0718 50%, var(--bg-deep) 100%);
}
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background: radial-gradient(ellipse 60% 40% at 50% 30%, var(--bg-glow) 0%, transparent 70%);
  pointer-events: none;
}
#starfield {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}

/* ---- Site header ---- */
header.site {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  background: rgba(6, 5, 14, 0.55);
  border-bottom: 1px solid var(--divider);
}
header.site .inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 1.2rem 2rem;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 2rem;
}
header.site .brand {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 1.35rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
}
header.site .brand .dot { color: var(--accent-bright); }
header.site .brand .path {
  font-family: var(--serif);
  font-size: 1.1rem;
  font-style: italic;
  font-weight: 300;
  color: var(--fg-dim);
  text-transform: none;
  letter-spacing: 0.02em;
  margin-left: 0.45rem;
}
header.site nav { display: flex; gap: 2.1rem; }
header.site nav a {
  color: var(--fg-mid);
  text-decoration: none;
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  padding: 0.3rem 0;
  position: relative;
  transition: color 0.3s var(--ease);
}
header.site nav a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -0.45rem;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.35s var(--ease);
}
header.site nav a:hover { color: var(--accent-bright); }
header.site nav a:hover::after { transform: scaleX(1); }
header.site nav a.current { color: var(--accent); }
header.site nav a.current::after { transform: scaleX(1); }

/* ---- Main container + page intro ---- */
main.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 5rem 2rem 8rem;
  position: relative;
}
main.narrow {
  max-width: 880px;
}

.page-intro {
  margin-bottom: 4rem;
  animation: intro 1.2s var(--ease) both;
}
@keyframes intro {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.overline {
  display: inline-block;
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.72rem;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 0.25rem 0 0.6rem;
  border-bottom: 1px solid var(--divider);
  margin-bottom: 1.6rem;
}
h1 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(3rem, 6vw, 5rem);
  line-height: 1.02;
  letter-spacing: -0.01em;
  color: var(--fg);
  margin-bottom: 0.6rem;
}
h1 em { font-style: italic; color: var(--accent-bright); font-weight: 300; }
.lead {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 300;
  font-size: clamp(1.15rem, 1.8vw, 1.5rem);
  color: var(--fg-mid);
  max-width: 58ch;
  line-height: 1.5;
}

h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(2rem, 3.2vw, 2.6rem);
  color: var(--fg);
  margin-top: 4.5rem;
  margin-bottom: 1.4rem;
  letter-spacing: -0.005em;
}
h2::before {
  content: "";
  display: block;
  width: 2.4rem;
  height: 1px;
  background: var(--accent);
  margin-bottom: 1.2rem;
}
h3 {
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--accent);
  margin-top: 1.4rem;
  margin-bottom: 0.7rem;
}
h4 {
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--fg);
}

p { margin-bottom: 1.1rem; color: var(--fg-mid); max-width: 66ch; font-size: 1.02rem; }
p.prose { font-family: var(--serif); font-size: 1.2rem; font-weight: 300; line-height: 1.65; color: var(--fg); max-width: 64ch; }
ul, ol { margin-bottom: 1.2rem; color: var(--fg-mid); }
ul { list-style: none; padding-left: 0; }
ul li {
  position: relative;
  padding-left: 1.4rem;
  margin-bottom: 0.55rem;
  max-width: 66ch;
}
ul li::before {
  content: "◆";
  position: absolute;
  left: 0;
  top: 0.1em;
  color: var(--accent);
  font-size: 0.65rem;
}

a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color 0.25s var(--ease), color 0.25s var(--ease); }
a:hover { color: var(--accent-bright); border-bottom-color: var(--accent); }

/* ---- Code + math display ---- */
code, pre, .mono { font-family: var(--mono); font-feature-settings: "liga" 0; }
code {
  color: var(--accent-bright);
  background: rgba(212, 168, 83, 0.08);
  padding: 0.1em 0.45em;
  border-radius: 3px;
  font-size: 0.85em;
  border: 1px solid rgba(212, 168, 83, 0.12);
}
pre {
  background: rgba(10, 7, 20, 0.6);
  border: 1px solid var(--divider-soft);
  border-left: 2px solid var(--accent);
  padding: 1rem 1.3rem;
  overflow-x: auto;
  margin: 1rem 0 1.4rem;
  font-size: 0.86rem;
  border-radius: 4px;
}
.math-display {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 1.25rem;
  color: var(--accent-bright);
  background: linear-gradient(180deg, rgba(20, 16, 42, 0.4) 0%, rgba(20, 16, 42, 0.15) 100%);
  border: 1px solid var(--divider);
  border-left: 3px solid var(--accent);
  padding: 1.4rem 1.8rem;
  border-radius: 5px;
  display: inline-block;
  min-width: 40%;
  margin: 0.6rem 0 2rem;
  position: relative;
  overflow: hidden;
}
.math-display::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 120% at 30% 0%, rgba(212, 168, 83, 0.10), transparent 60%);
  pointer-events: none;
}

/* ---- Panels / cards ---- */
.panel {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 1.6rem 1.9rem;
  margin-bottom: 1.2rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}
.panel.tight { padding: 1rem 1.3rem; }
.panel:hover { border-color: var(--accent-deep); }
a.panel { display: block; color: var(--fg); text-decoration: none; border-bottom: none; }
a.panel:hover { transform: translateY(-2px); }

/* ---- Stat grid (home) ---- */
.stat-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  margin: 1rem 0 2.5rem;
}
.stat {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 1.8rem 1.7rem 1.5rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  position: relative;
  overflow: hidden;
}
.stat::before {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0.6;
}
.stat .value {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 3.4rem;
  line-height: 0.95;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.stat .label {
  font-family: var(--sans);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--fg-dim);
  margin-top: 0.5rem;
}

/* ---- Card grids for indexes ---- */
.card-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  margin: 1.5rem 0 3rem;
}
.card {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 1.5rem 1.6rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: border-color 0.35s var(--ease), transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
  position: relative;
  overflow: hidden;
  display: block;
  color: var(--fg);
  text-decoration: none;
  border-bottom: none;
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: 0 12px 40px -12px rgba(212, 168, 83, 0.25);
}
.card .card-id {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: var(--accent);
  margin-bottom: 0.35rem;
}
.card .card-name {
  font-family: var(--serif);
  font-size: 1.55rem;
  color: var(--fg);
  line-height: 1.15;
  margin-bottom: 0.7rem;
  font-weight: 400;
}
.card .card-math {
  font-family: var(--mono);
  font-size: 0.88rem;
  color: var(--accent-bright);
  background: rgba(212, 168, 83, 0.06);
  padding: 0.55rem 0.8rem;
  border-radius: 3px;
  border: 1px solid rgba(212, 168, 83, 0.12);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: block;
}
.card .card-meta {
  font-size: 0.74rem;
  color: var(--fg-dim);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-top: 0.9rem;
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ---- Domain section headers ---- */
.domain-section { margin-bottom: 3rem; }
.domain-section .domain-label {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 300;
  font-size: 1.4rem;
  color: var(--fg-dim);
  letter-spacing: 0.05em;
  margin-bottom: 1.2rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--divider-soft);
}

/* ---- Coupling detail: A↔B pairing layout ---- */
.pairing {
  display: grid;
  grid-template-columns: 1fr 80px 1fr;
  gap: 0;
  align-items: stretch;
  margin: 2rem 0 3rem;
}
.pairing .side {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 2rem 2rem 1.7rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.pairing .side.left { border-right: none; border-top-right-radius: 0; border-bottom-right-radius: 0; }
.pairing .side.right { border-left: none; border-top-left-radius: 0; border-bottom-left-radius: 0; }
.pairing .side .side-label {
  font-size: 0.66rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--fg-dim);
  margin-bottom: 0.7rem;
}
.pairing .side .side-eq-id {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 0.4rem;
}
.pairing .side .side-var {
  font-family: var(--serif);
  font-size: 3rem;
  line-height: 1;
  color: var(--accent-bright);
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 0.9rem;
}
.pairing .connector {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: radial-gradient(ellipse 100% 60% at 50% 50%, rgba(212, 168, 83, 0.25), transparent 70%);
}
.pairing .connector .arrow {
  font-family: var(--serif);
  font-weight: 300;
  font-size: 3rem;
  color: var(--accent);
  animation: pulse 3.5s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 0.55; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.08); }
}
@media (max-width: 720px) {
  .pairing { grid-template-columns: 1fr; }
  .pairing .side.left { border-right: 1px solid var(--divider); border-bottom: none; border-radius: 6px 6px 0 0; }
  .pairing .side.right { border-left: 1px solid var(--divider); border-radius: 0 0 6px 6px; }
  .pairing .connector { padding: 1rem 0; }
}

/* ---- Key/value descriptor blocks ---- */
dl.kv {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.5rem 1.2rem;
  margin: 0.6rem 0;
}
dl.kv dt {
  font-family: var(--sans);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg-dim);
  padding-top: 0.15rem;
}
dl.kv dd {
  font-family: var(--mono);
  font-size: 0.86rem;
  color: var(--fg);
}

/* ---- Badges ---- */
.badge {
  display: inline-block;
  padding: 0.22em 0.7em;
  border-radius: 2px;
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.68rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}
.badge.proved      { color: var(--proved); border: 1px solid rgba(141, 255, 184, 0.4); background: rgba(141, 255, 184, 0.06); }
.badge.empirical   { color: var(--empirical); border: 1px solid rgba(168, 198, 255, 0.38); background: rgba(168, 198, 255, 0.06); }
.badge.conjectural { color: var(--conjectural); border: 1px solid rgba(245, 210, 107, 0.36); background: rgba(245, 210, 107, 0.06); }
.badge.rejected    { color: var(--rejected); border: 1px solid rgba(255, 138, 104, 0.38); background: rgba(255, 138, 104, 0.06); }
.badge.tier1 { color: var(--accent-bright); border: 1px solid var(--accent); background: rgba(212, 168, 83, 0.12); }
.badge.tier2 { color: var(--accent); border: 1px solid var(--accent-deep); background: rgba(212, 168, 83, 0.06); }
.badge.tier3 { color: var(--fg-dim); border: 1px solid var(--fg-dim); }
.badge.neutral { color: var(--fg-dim); border: 1px solid var(--divider); }

/* ---- Constraint / review cards ---- */
.check-card {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-left: 3px solid var(--divider);
  border-radius: 4px;
  padding: 1.1rem 1.4rem;
  margin-bottom: 0.8rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.check-card.passed { border-left-color: var(--proved); }
.check-card.failed { border-left-color: var(--rejected); }
.check-card.not_applicable { border-left-color: var(--fg-dim); opacity: 0.72; }
.check-card .check-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.5rem;
}
.check-card .check-name {
  font-family: var(--sans);
  font-weight: 500;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--fg);
}
.check-card .reasoning {
  font-family: var(--serif);
  font-size: 1.02rem;
  line-height: 1.55;
  color: var(--fg-mid);
  font-style: italic;
}

.reviewer-card {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 1.5rem 1.8rem;
  margin-bottom: 1rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  position: relative;
}
.reviewer-card .reviewer-head {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 0.9rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--divider-soft);
}
.reviewer-card .reviewer-name {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--accent);
}
.reviewer-card .reasoning {
  font-family: var(--serif);
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--fg);
}

/* ---- Ledger / logbook table ---- */
.logbook {
  background: rgba(10, 7, 20, 0.55);
  border: 1px solid var(--divider-soft);
  border-radius: 5px;
  overflow: hidden;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  margin: 1.5rem 0 3rem;
}
.logbook-row {
  display: grid;
  grid-template-columns: 3.5rem 1fr 1fr 1.2fr 8rem 3rem;
  gap: 0.8rem;
  padding: 0.65rem 1.3rem;
  border-bottom: 1px solid var(--divider-soft);
  font-family: var(--mono);
  font-size: 0.78rem;
  align-items: center;
  transition: background 0.25s var(--ease);
}
.logbook-row:last-child { border-bottom: none; }
.logbook-row:hover { background: rgba(212, 168, 83, 0.04); }
.logbook-row.head {
  color: var(--fg-dim);
  font-family: var(--sans);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  font-size: 0.68rem;
  padding-top: 0.95rem;
  padding-bottom: 0.95rem;
  background: rgba(212, 168, 83, 0.04);
  border-bottom: 1px solid var(--divider);
}
.logbook-row .idx { color: var(--fg-dim); }
.logbook-row .eq { color: var(--accent); font-size: 0.76rem; }
.logbook-row .kind { color: var(--fg-mid); font-size: 0.73rem; }
@media (max-width: 780px) {
  .logbook-row { grid-template-columns: 2.5rem 1fr 5rem; }
  .logbook-row .kind, .logbook-row .review, .logbook-row .eq-b { display: none; }
}

/* ---- Phase cards (home "how it works") ---- */
.phases {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0 3rem;
}
.phase {
  background: var(--bg-panel);
  border: 1px solid var(--divider);
  border-radius: 6px;
  padding: 1.9rem 1.8rem 1.7rem;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: border-color 0.3s var(--ease);
}
.phase:hover { border-color: var(--accent-deep); }
.phase .roman {
  font-family: var(--serif);
  font-style: italic;
  font-size: 2.4rem;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.9rem;
  display: block;
}
.phase h3 { margin: 0 0 0.6rem; color: var(--fg); font-family: var(--serif); font-weight: 400; font-size: 1.35rem; text-transform: none; letter-spacing: 0; }
.phase p { font-size: 0.94rem; color: var(--fg-mid); font-family: var(--sans); }

/* ---- Footer ---- */
footer.site {
  margin-top: 5rem;
  padding: 2.5rem 0 1rem;
  border-top: 1px solid var(--divider-soft);
  color: var(--fg-dim);
  font-size: 0.8rem;
  text-align: center;
  letter-spacing: 0.06em;
}
footer.site p { color: var(--fg-dim); max-width: none; margin: 0 auto 0.4rem; }

/* ---- Back link ---- */
.back-link {
  display: inline-block;
  margin-top: 3rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--fg-dim);
  border-bottom: 1px solid transparent;
}
.back-link:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* ---- Filter bar (future hook) ---- */
.filter-bar {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin: 1.2rem 0 2rem;
}