/* ============================================================================
   Unified Foam Field Theory — site styles
   Physicist-facing. Dark, precise, document-like.
   ========================================================================== */

:root {
  --bg:        #0a0d12;
  --bg-grad:   #0c1119;
  --panel:     #121822;
  --panel-2:   #161d28;
  --border:    #243043;
  --border-2:  #2e3c52;
  --text:      #e6edf3;
  --text-dim:  #9aa7b8;
  --text-faint:#6b7888;
  --accent:    #5ad1c8;   /* foam teal   */
  --accent-2:  #f0b429;   /* amber       */
  --accent-dim:#2b6f6a;

  /* status tiers */
  --t1: #3fb950;  /* Tier 1 — theorem      */
  --t2: #58a6ff;  /* Tier 2 — derived      */
  --t3: #d29922;  /* Tier 3 — tension      */
  --t4: #a371f7;  /* Tier 4 — suggestive   */

  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;

  --maxw: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    radial-gradient(1200px 700px at 78% -8%, #14202e 0%, rgba(20,32,46,0) 60%),
    radial-gradient(900px 600px at 10% 110%, #122021 0%, rgba(18,32,33,0) 55%),
    var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---- top nav ------------------------------------------------------------ */
header.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10,13,18,0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; gap: 22px;
}
.brand { display: flex; align-items: baseline; gap: 12px; margin-right: auto; }
.brand .logo {
  font-family: var(--mono); font-weight: 700; letter-spacing: .5px;
  color: var(--accent); font-size: 18px;
  border: 1px solid var(--accent-dim); padding: 3px 9px; border-radius: 7px;
}
.brand .name { font-size: 15px; color: var(--text-dim); font-weight: 600; }
nav.links a {
  color: var(--text-dim); font-size: 15px; font-weight: 500;
  margin-left: 20px; padding: 4px 0; border-bottom: 2px solid transparent;
}
nav.links a:hover { color: var(--text); text-decoration: none; }
nav.links a.active { color: var(--text); border-bottom-color: var(--accent); }
nav.links a.ext::after { content: " ↗"; color: var(--text-faint); font-size: 12px; }
.nav-toggle { display: none; }

@media (max-width: 760px) {
  .nav-inner { flex-wrap: wrap; }
  nav.links { width: 100%; display: none; }
  nav.links.open { display: block; }
  nav.links a { display: inline-block; margin: 6px 18px 6px 0; }
  .nav-toggle {
    display: inline-block; background: none; border: 1px solid var(--border-2);
    color: var(--text-dim); border-radius: 6px; padding: 4px 10px; cursor: pointer;
  }
}

/* ---- hero --------------------------------------------------------------- */
.hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--border); }
.hero-grid {
  max-width: var(--maxw); margin: 0 auto; padding: 64px 24px 56px;
  display: grid; grid-template-columns: 1.15fr 1fr; gap: 40px; align-items: center;
}
#foam-canvas { width: 100%; height: 420px; display: block; }
.hero-canvas-wrap {
  position: relative; border: 1px solid var(--border);
  border-radius: 14px; background: linear-gradient(180deg, #0e1622, #0a0f17);
  overflow: hidden;
}
.hero-canvas-cap {
  position: absolute; bottom: 0; left: 0; right: 0;
  font-family: var(--mono); font-size: 12px; color: var(--text-faint);
  padding: 8px 12px; background: linear-gradient(0deg, rgba(10,13,18,.9), transparent);
}
.eyebrow {
  font-family: var(--mono); font-size: 13px; letter-spacing: 2px;
  text-transform: uppercase; color: var(--accent); margin-bottom: 14px;
}
h1.title { font-size: 40px; line-height: 1.12; margin: 0 0 16px; font-weight: 700; letter-spacing: -.5px; }
h1.title .em { color: var(--accent); }
.lede { font-size: 19px; color: var(--text-dim); margin: 0 0 24px; }
.axiom {
  display: inline-flex; align-items: center; gap: 14px;
  font-family: var(--mono); font-size: 22px; color: var(--text);
  background: var(--panel); border: 1px solid var(--border-2);
  border-radius: 10px; padding: 12px 18px; margin-bottom: 8px;
}
.axiom .tag { font-size: 12px; color: var(--text-faint); font-family: var(--sans); letter-spacing: .5px; }

.btnrow { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }
.btn {
  display: inline-block; padding: 11px 20px; border-radius: 9px; font-weight: 600;
  font-size: 15px; border: 1px solid transparent; cursor: pointer;
}
.btn.primary { background: var(--accent); color: #06231f; }
.btn.primary:hover { background: #7adfd7; text-decoration: none; }
.btn.ghost { border-color: var(--border-2); color: var(--text); }
.btn.ghost:hover { border-color: var(--accent); text-decoration: none; }

@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  h1.title { font-size: 32px; }
}

/* ---- sections ----------------------------------------------------------- */
section { padding: 56px 0; border-bottom: 1px solid var(--border); }
section:last-of-type { border-bottom: none; }
.section-eyebrow {
  font-family: var(--mono); font-size: 12px; letter-spacing: 2px;
  text-transform: uppercase; color: var(--text-faint); margin-bottom: 10px;
}
h2 { font-size: 28px; margin: 0 0 8px; font-weight: 700; letter-spacing: -.3px; }
h3 { font-size: 20px; margin: 32px 0 10px; font-weight: 650; }
.section-sub { color: var(--text-dim); max-width: 70ch; margin: 0 0 28px; }
p { max-width: 74ch; }
.muted { color: var(--text-dim); }
.faint { color: var(--text-faint); }

/* ---- KPI cards ---------------------------------------------------------- */
.kpis { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.kpi {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 18px 18px 16px;
}
.kpi .v { font-family: var(--mono); font-size: 26px; color: var(--accent); font-weight: 600; }
.kpi .k { font-size: 13.5px; color: var(--text); margin-top: 4px; font-weight: 600; }
.kpi .s { font-size: 12.5px; color: var(--text-faint); margin-top: 2px; }
@media (max-width: 860px) { .kpis { grid-template-columns: repeat(2, 1fr); } }

/* ---- cards / chain ------------------------------------------------------ */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 22px;
}
.card h3 { margin-top: 0; }
.card .num {
  font-family: var(--mono); font-size: 13px; color: var(--accent);
  border: 1px solid var(--accent-dim); border-radius: 6px; padding: 1px 8px;
}
@media (max-width: 860px) { .cards { grid-template-columns: 1fr; } }

.chain { display: flex; flex-direction: column; gap: 0; margin: 8px 0; }
.chain .step {
  display: grid; grid-template-columns: 44px 1fr; gap: 16px; padding: 18px 0;
  border-bottom: 1px dashed var(--border);
}
.chain .step:last-child { border-bottom: none; }
.chain .dot {
  width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--accent-dim);
  color: var(--accent); font-family: var(--mono); font-weight: 700;
  display: flex; align-items: center; justify-content: center; background: var(--panel);
}
.chain .step h3 { margin: 2px 0 6px; }

/* ---- tables ------------------------------------------------------------- */
.tbl-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--border); vertical-align: top; }
thead th {
  background: var(--panel-2); color: var(--text-dim); font-weight: 600;
  font-size: 13px; letter-spacing: .4px; text-transform: uppercase; position: sticky; top: 0;
}
tbody tr:hover { background: rgba(90,209,200,0.04); }
td.formula, td.mono, .mono { font-family: var(--mono); font-size: 14px; }
td.val { font-family: var(--mono); color: var(--accent); white-space: nowrap; }
tbody tr:last-child td { border-bottom: none; }

/* ---- tier badges -------------------------------------------------------- */
.badge {
  display: inline-block; font-size: 11.5px; font-weight: 700; letter-spacing: .3px;
  padding: 2px 9px; border-radius: 20px; white-space: nowrap;
  font-family: var(--mono);
}
.badge.t1 { color: var(--t1); background: rgba(63,185,80,.12);  border: 1px solid rgba(63,185,80,.4); }
.badge.t2 { color: var(--t2); background: rgba(88,166,255,.12); border: 1px solid rgba(88,166,255,.4); }
.badge.t3 { color: var(--t3); background: rgba(210,153,34,.12); border: 1px solid rgba(210,153,34,.4); }
.badge.t4 { color: var(--t4); background: rgba(163,113,247,.12);border: 1px solid rgba(163,113,247,.4); }
.legend { display: flex; gap: 18px; flex-wrap: wrap; margin: 0 0 22px; font-size: 14px; color: var(--text-dim); }
.legend .item { display: flex; align-items: center; gap: 8px; }

/* ---- callouts ----------------------------------------------------------- */
.callout {
  border-left: 3px solid var(--accent); background: var(--panel);
  border-radius: 0 10px 10px 0; padding: 16px 20px; margin: 24px 0;
}
.callout.warn { border-left-color: var(--accent-2); }
.callout.kill { border-left-color: var(--t3); }
.callout h3 { margin-top: 0; }

/* ---- code --------------------------------------------------------------- */
.code-wrap { position: relative; margin: 18px 0; }
pre {
  background: #0b1017; border: 1px solid var(--border); border-radius: 12px;
  padding: 20px 20px; overflow-x: auto; font-family: var(--mono);
  font-size: 13.5px; line-height: 1.6; color: #d7e2ee; margin: 0;
}
pre .cm { color: #6b7888; }      /* comment */
pre .kw { color: #ff7b72; }      /* keyword */
pre .fn { color: #d2a8ff; }      /* fn      */
pre .st { color: #7ee787; }      /* string/number out */
.copy-btn {
  position: absolute; top: 10px; right: 10px; font-family: var(--sans);
  font-size: 12px; color: var(--text-dim); background: var(--panel-2);
  border: 1px solid var(--border-2); border-radius: 6px; padding: 4px 10px; cursor: pointer;
}
.copy-btn:hover { color: var(--text); border-color: var(--accent); }
code.inline { font-family: var(--mono); font-size: 14px; background: var(--panel-2);
  padding: 1px 6px; border-radius: 5px; border: 1px solid var(--border); color: var(--accent); }

/* ---- viz panels --------------------------------------------------------- */
.viz {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 18px; margin: 22px 0;
}
.viz .cap { font-size: 13px; color: var(--text-faint); margin-top: 10px; font-family: var(--mono); }
#spectrum-chart, #parabola-chart { width: 100%; height: 360px; }

/* ---- footer ------------------------------------------------------------- */
footer {
  padding: 40px 0 56px; color: var(--text-faint); font-size: 14px;
  border-top: 1px solid var(--border);
}
footer .wrap { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 28px; }
footer h4 { color: var(--text-dim); font-size: 13px; text-transform: uppercase; letter-spacing: .6px; margin: 0 0 10px; }
footer a { color: var(--text-dim); display: block; margin: 5px 0; }
footer .sig { font-family: var(--mono); color: var(--accent); }
footer .disc { grid-column: 1 / -1; border-top: 1px solid var(--border); padding-top: 18px; margin-top: 8px; max-width: 80ch; }
@media (max-width: 760px) { footer .wrap { grid-template-columns: 1fr; } }

/* ---- eigenmode explorer ------------------------------------------------- */
.eigen-modes { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.eigen-mode-btn {
  display: flex; flex-direction: column; align-items: flex-start; gap: 2px;
  background: var(--panel-2); border: 1px solid var(--border-2); border-radius: 9px;
  padding: 8px 12px; cursor: pointer; color: var(--text); font-family: var(--sans);
  text-align: left; transition: border-color .15s, background .15s;
}
.eigen-mode-btn:hover { border-color: var(--accent); }
.eigen-mode-btn.active { border-color: var(--accent); background: rgba(90,209,200,0.10); }
.eigen-mode-btn .em-name { font-size: 14px; font-weight: 650; }
.eigen-mode-btn .em-sym { font-family: var(--mono); font-size: 11.5px; color: var(--text-faint); }
.eigen-mode-btn.active .em-sym { color: var(--accent); }

.eigen-stage { position: relative; border: 1px solid var(--border); border-radius: 10px;
  overflow: hidden; background: linear-gradient(180deg, #0e1622, #0a0f17); }
#eigen-canvas { width: 100%; height: 460px; display: block; }
.eigen-ev {
  position: absolute; top: 14px; right: 16px; text-align: right; pointer-events: none;
  display: flex; flex-direction: column; gap: 2px;
}
.eigen-ev .evk { font-family: var(--serif); font-size: 22px; color: var(--accent); font-weight: 700; }
.eigen-ev .evs { font-family: var(--mono); font-size: 12px; color: var(--text-dim); }

.eigen-ctrls { display: flex; flex-wrap: wrap; align-items: center; gap: 22px; margin: 14px 0 6px; }
.eigen-legend { display: flex; gap: 16px; font-size: 13px; color: var(--text-dim); }
.eigen-legend .li { display: flex; align-items: center; gap: 7px; }
.eigen-legend .sw { width: 13px; height: 13px; border-radius: 3px; }
.eigen-ctrls label { font-size: 13px; color: var(--text-dim); display: flex; align-items: center; gap: 8px; }
.eigen-ctrls input[type=range] { accent-color: var(--accent); width: 110px; }
.eigen-info { font-size: 14.5px; color: var(--text-dim); line-height: 1.55; margin-top: 6px; }
.eigen-info strong { color: var(--text); }
.eigen-info .em-faces { color: var(--text-faint); }

/* ---- papers page -------------------------------------------------------- */
.papers-bar { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-top: 6px; }
.paper-search {
  flex: 1; min-width: 240px; background: var(--panel); border: 1px solid var(--border-2);
  border-radius: 9px; padding: 11px 15px; color: var(--text); font-size: 15px; font-family: var(--sans);
}
.paper-search:focus { outline: none; border-color: var(--accent); }
.paper-search::placeholder { color: var(--text-faint); }
.paper-count { font-family: var(--mono); font-size: 13px; color: var(--text-faint); white-space: nowrap; }

.paper-cat { padding: 26px 0 0; border: none; }
.paper-cat-h {
  font-size: 14px; text-transform: uppercase; letter-spacing: 1.2px; color: var(--accent);
  margin: 0 0 14px; font-weight: 650; border-bottom: 1px solid var(--border); padding-bottom: 8px;
}
.paper-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
@media (max-width: 760px) { .paper-grid { grid-template-columns: 1fr; } }
.paper-card {
  display: block; background: var(--panel); border: 1px solid var(--border); border-radius: 11px;
  padding: 16px 18px; text-decoration: none; color: var(--text); transition: border-color .15s, transform .12s, background .15s;
}
.paper-card:hover { border-color: var(--accent); background: rgba(90,209,200,0.04); text-decoration: none; transform: translateY(-1px); }
.pc-tag { font-family: var(--mono); font-size: 11.5px; color: var(--accent); letter-spacing: .3px; }
.pc-title { font-size: 16px; font-weight: 650; margin: 5px 0 6px; line-height: 1.3; color: var(--text); }
.pc-sum { font-size: 13.5px; color: var(--text-dim); line-height: 1.5; }
.pc-doi { font-family: var(--mono); font-size: 11.5px; color: var(--text-faint); margin-top: 10px;
  display: flex; justify-content: space-between; gap: 10px; flex-wrap: wrap; align-items: baseline; }
.pc-arrow { color: var(--accent); }

/* katex sizing */
.katex { font-size: 1.02em; }
.katex-display { margin: 18px 0; overflow-x: auto; overflow-y: hidden; }