:root {
  --paper: #fbfaf6;
  --paper-2: #f3f1ea;
  --ink: #1d2733;
  --muted: #5b6673;
  --faint: #7a8490;
  --rule: #cfd4d8;
  --rule-dark: #9da7b0;
  --navy: #18324a;
  --navy-soft: #e8eef3;
  --plot-bg: #ffffff;
  --plot-grid: #dfe4e7;
  --plot-axis: #66727e;
  --plot-wave: #173a5e;
  --plot-density: #6b3f1d;
  --max: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.62;
}

a { color: var(--navy); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
button, input { font: inherit; }
.container { width: min(var(--max), calc(100% - 44px)); margin: 0 auto; }

.site-header {
  background: rgba(251,250,246,.96);
  border-bottom: 1px solid var(--rule);
}
.nav-wrap {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.01em;
}
.brand-mark {
  color: var(--navy);
  font-size: 23px;
  font-style: italic;
}
.nav {
  display: flex;
  gap: 25px;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 13px;
}
.nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 4px 0;
}
.nav a:hover { color: var(--navy); }

.hero { padding: 66px 0 56px; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(290px, .85fr);
  gap: 58px;
  align-items: start;
}
.eyebrow {
  margin: 0 0 10px;
  color: var(--navy);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .13em;
  text-transform: uppercase;
}
.hero h1, .section-heading h2, .about-section h2 {
  margin: 0;
  color: var(--ink);
  line-height: 1.08;
  font-weight: 700;
  letter-spacing: -.02em;
}
.hero h1 { font-size: clamp(42px, 6vw, 70px); max-width: 820px; }
.hero h1 span { color: var(--navy); }
.hero-text {
  max-width: 740px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 18px;
}
.hero-meta {
  margin-top: 24px;
  color: var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 12px;
}
.hero-meta b { color: var(--ink); }

.scope-card {
  border-top: 3px solid var(--navy);
  border-bottom: 1px solid var(--rule-dark);
  padding: 18px 0 14px;
}
.scope-card h2 {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: 700;
}
.scope-row {
  padding: 13px 0;
  border-top: 1px solid var(--rule);
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
}
.scope-row span {
  color: var(--navy);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 12px;
  font-weight: 700;
}
.scope-row b { display:block; font-size: 15px; }
.scope-row small { display:block; color: var(--muted); font-size: 12px; margin-top: 2px; }

.intro-strip {
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  background: var(--paper-2);
}
.intro-grid {
  display: grid;
  grid-template-columns: repeat(3,1fr);
}
.intro-grid > div {
  padding: 18px 20px 18px 0;
  margin-right: 20px;
  border-right: 1px solid var(--rule);
}
.intro-grid > div:last-child { border-right: 0; margin-right: 0; }
.strip-label {
  display:block;
  color: var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 10px;
  letter-spacing: .11em;
  text-transform: uppercase;
  margin-bottom: 3px;
}
.intro-grid strong { color: var(--ink); font-size: 14px; font-weight: 700; }

.system-section { padding: 76px 0 38px; }
.alt-section { border-top: 1px solid var(--rule); padding-top: 72px; }
.section-heading {
  display: grid;
  grid-template-columns: minmax(0,1fr) minmax(310px,.72fr);
  gap: 40px;
  align-items: end;
  margin-bottom: 28px;
}
.section-heading h2, .about-section h2 { font-size: clamp(31px, 4vw, 48px); }
.section-heading p:not(.eyebrow) {
  color: var(--muted);
  max-width: 760px;
  margin: 13px 0 0;
  font-size: 16px;
}

.formula-card {
  padding: 15px 17px 16px;
  border-top: 2px solid var(--navy);
  border-bottom: 1px solid var(--rule-dark);
  background: var(--paper-2);
}
.formula-card span {
  display:block;
  color: var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 10px;
  font-weight: 700;
  letter-spacing:.11em;
  text-transform: uppercase;
  margin-bottom: 9px;
}
.formula-card math {
  color: var(--ink);
  font-size: 1.2rem;
}
.formula-card .formula-line + .formula-line { margin-top: 8px; }
.formula-note {
  margin-top: 10px;
  color: var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 10px;
}

.workspace {
  display: grid;
  grid-template-columns: 255px minmax(0,1fr);
  gap: 20px;
  align-items: stretch;
}
.controls-panel, .graph-card, .method-card, .oscillator-note {
  border: 1px solid var(--rule);
  background: rgba(255,255,255,.48);
  border-radius: 3px;
}
.controls-panel { padding: 19px; }
.panel-title {
  margin-bottom: 20px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing:.08em;
  text-transform: uppercase;
}
.control-group { margin-bottom: 21px; }
.control-head {
  display:flex;
  justify-content:space-between;
  gap:12px;
  align-items:center;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 12px;
  color: var(--ink);
}
.control-head b { font-family: Georgia, "Times New Roman", serif; font-style: italic; }
.control-head output {
  min-width: 42px;
  text-align:right;
  color: var(--navy);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
input[type="range"] {
  width:100%;
  margin: 12px 0 4px;
  accent-color: var(--navy);
  cursor:pointer;
}
.range-labels {
  display:flex;
  justify-content:space-between;
  color:var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size:9px;
}
.metric-card {
  margin-top: 22px;
  padding: 15px 16px;
  background: var(--navy-soft);
  border-left: 3px solid var(--navy);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.metric-card span {
  display:block;
  color:var(--faint);
  font-family: Arial, Helvetica, sans-serif;
  font-size:10px;
  letter-spacing:.1em;
  text-transform:uppercase;
}
.metric-card strong {
  display:block;
  color:var(--navy);
  font-family: Cambria, Georgia, "Times New Roman", serif;
  font-size: 28px;
  line-height:1.2;
  margin: 4px 0;
  font-variant-numeric: tabular-nums;
}
.metric-card small {
  display:block;
  color:var(--muted);
  font-size:11px;
}
.metric-row {
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:8px;
  margin-top:10px;
}
.metric-row > div {
  border-top:1px solid var(--rule);
  padding-top:9px;
}
.metric-row span {
  display:block;
  color:var(--faint);
  font-family:Arial, Helvetica, sans-serif;
  font-size:9px;
  letter-spacing:.09em;
  text-transform:uppercase;
}
.metric-row strong {
  display:block;
  color:var(--ink);
  margin-top:3px;
  font-family:Arial, Helvetica, sans-serif;
  font-size:14px;
  font-variant-numeric:tabular-nums;
}

.graphs-grid { display:grid; grid-template-columns:1fr 1fr; gap:20px; }
.graph-card { min-width:0; overflow:hidden; }
.graph-head {
  padding: 15px 17px 11px;
  border-bottom:1px solid var(--rule);
  display:flex;
  justify-content:space-between;
  gap:15px;
  align-items:start;
}
.graph-head h3 {
  margin:0;
  color:var(--ink);
  font-size: 16px;
  font-weight:700;
}
.graph-head p {
  margin:4px 0 0;
  color:var(--muted);
  font-size:11px;
  font-family: Arial, Helvetica, sans-serif;
  line-height:1.45;
}
.graph-chip {
  padding-top: 2px;
  color: var(--navy);
  font-family: Cambria, Georgia, serif;
  font-size: 16px;
  white-space: nowrap;
}
.canvas-wrap { height: 335px; padding: 8px 8px 9px; }
canvas { width:100%; height:100%; display:block; }

.insight-row {
  display:grid;
  grid-template-columns: repeat(3,1fr);
  gap:15px;
  margin-top:16px;
}
.insight {
  padding: 13px 14px;
  border-top:1px solid var(--rule-dark);
  color:var(--muted);
  font-size:12px;
}
.insight-number {
  display:block;
  color:var(--navy);
  font-family:Arial, Helvetica, sans-serif;
  font-size:10px;
  font-weight:700;
  margin-bottom:3px;
}
.insight p { margin:0; }

.oscillator-note {
  margin-top:18px;
  padding: 14px 16px;
  display:flex;
  gap:12px;
  color:var(--muted);
  font-size:12px;
}
.note-icon {
  width: 22px;
  height:22px;
  flex:none;
  display:grid;
  place-items:center;
  border:1px solid var(--rule-dark);
  color:var(--navy);
  font-family:Georgia, serif;
  font-weight:700;
}

.about-section {
  padding: 78px 0 94px;
  border-top:1px solid var(--rule);
}
.about-grid { display:grid; grid-template-columns:1fr 1fr; gap:50px; align-items:start; }
.about-section p { color:var(--muted); max-width:680px; }
.about-section .muted { color:var(--faint); font-family:Arial, Helvetica, sans-serif; font-size:12px; }
.method-card { padding: 7px 16px; }
.method-step {
  display:flex;
  gap:14px;
  padding:14px 0;
  border-bottom:1px solid var(--rule);
}
.method-step:last-child { border-bottom:0; }
.method-step > span {
  width:26px;
  height:26px;
  display:grid;
  place-items:center;
  border:1px solid var(--rule-dark);
  color:var(--navy);
  font-family:Arial, Helvetica, sans-serif;
  font-size:10px;
  font-weight:700;
}
.method-step b { display:block; font-family:Arial, Helvetica, sans-serif; font-size:12px; }
.method-step small { display:block; color:var(--muted); font-size:11px; margin-top:2px; }

.site-footer {
  border-top:1px solid var(--rule);
  padding:24px 0 30px;
  color:var(--faint);
  font-family:Arial, Helvetica, sans-serif;
  font-size:10px;
}
.footer-wrap { display:flex; justify-content:space-between; gap:20px; }
.footer-wrap b { color:var(--ink); margin-right:10px; }
.footer-wrap span { font-size:10px; }

@media (max-width: 980px) {
  .hero-grid { grid-template-columns:1fr; gap:30px; }
  .section-heading { grid-template-columns:1fr; gap:20px; }
  .formula-card { width:100%; }
  .workspace { grid-template-columns:1fr; }
  .controls-panel { display:grid; grid-template-columns:repeat(3,1fr); gap:0 16px; }
  .panel-title { grid-column:1 / -1; }
  .metric-card { margin-top:0; }
  .metric-row { margin-top:0; }
}

@media (max-width: 760px) {
  .container { width:min(var(--max), calc(100% - 24px)); }
  .nav { display:none; }
  .hero { padding-top:48px; }
  .hero h1 { font-size:46px; }
  .hero-text { font-size:16px; }
  .intro-grid { grid-template-columns:1fr; }
  .intro-grid > div { border-right:0; border-bottom:1px solid var(--rule); margin:0; padding:14px 0; }
  .intro-grid > div:last-child { border-bottom:0; }
  .controls-panel { grid-template-columns:1fr; }
  .metric-card, .metric-row { margin-top:20px; }
  .graphs-grid { grid-template-columns:1fr; }
  .canvas-wrap { height:285px; }
  .insight-row { grid-template-columns:1fr; }
  .about-grid { grid-template-columns:1fr; gap:26px; }
  .footer-wrap { flex-direction:column; gap:8px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior:auto; }
}