:root {
  --paper: #f4f0e7;
  --paper-deep: #e8e0d0;
  --ink: #182824;
  --muted: #66736d;
  --hairline: rgba(24, 40, 36, 0.18);
  --river: #167c74;
  --river-dark: #0a5752;
  --river-pale: #a9d4c8;
  --clay: #bb604a;
  --gold: #c09a4b;
  --violet: #6c648e;
  --blue: #4e7891;
  --moss: #6e814f;
  --shadow: 0 22px 70px rgba(36, 48, 43, 0.10);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background:
    radial-gradient(circle at 84% 4%, rgba(22, 124, 116, 0.09), transparent 27rem),
    linear-gradient(rgba(24,40,36,.025) 1px, transparent 1px),
    var(--paper);
  background-size: auto, 100% 28px, auto;
}

button, select, input { font: inherit; }
button, select { color: inherit; }
button { cursor: pointer; }

.masthead {
  min-height: 68px;
  padding: 0 5vw;
  border-bottom: 1px solid var(--hairline);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  gap: .7rem;
  align-items: center;
  color: inherit;
  text-decoration: none;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.08rem;
}

.brand-mark {
  width: 31px;
  height: 31px;
  border: 1px solid var(--ink);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-style: italic;
}

.edition {
  color: var(--muted);
  font-size: .72rem;
  letter-spacing: .12em;
  text-transform: uppercase;
}

main { width: min(1420px, 92vw); margin: 0 auto; }

.intro {
  padding: clamp(3.6rem, 8vw, 7rem) 0 clamp(2rem, 4vw, 3.7rem);
  max-width: 850px;
}

.eyebrow {
  margin: 0 0 .65rem;
  color: var(--river-dark);
  font-size: .7rem;
  letter-spacing: .2em;
  font-weight: 700;
}

h1, h2, h3, p { margin-top: 0; }
h1, h2 { font-family: Georgia, "Times New Roman", serif; font-weight: 400; }
h1 { font-size: clamp(3rem, 7vw, 6.8rem); letter-spacing: -.055em; line-height: .94; margin-bottom: 1.3rem; }
.lede { max-width: 680px; color: var(--muted); font-size: clamp(1rem, 2vw, 1.25rem); line-height: 1.65; }

.mode-switch {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--hairline);
  border-bottom: 1px solid var(--hairline);
}

.mode-button {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 1.2rem 1rem;
  display: flex;
  text-align: left;
  align-items: center;
  gap: 1rem;
  min-height: 86px;
}
.mode-button + .mode-button { border-left: 1px solid var(--hairline); }
.mode-button:hover { background: rgba(255,255,255,.28); }
.mode-button.active { box-shadow: inset 0 -3px 0 var(--river); background: rgba(255,255,255,.38); }
.mode-number { font-family: Georgia, serif; color: var(--clay); font-style: italic; }
.mode-button strong, .mode-button small { display: block; }
.mode-button strong { font-family: Georgia, serif; font-weight: 400; font-size: 1.1rem; }
.mode-button small { color: var(--muted); margin-top: .2rem; }

.workspace { padding: 2rem 0 0; }
.control-strip {
  display: grid;
  grid-template-columns: auto minmax(180px, 280px) auto minmax(230px, 1fr);
  align-items: end;
  gap: 1rem;
  margin-bottom: 1rem;
}
.field-label, .time-label-row, .compact-range span { font-size: .74rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.field-label { align-self: center; }
.select-control {
  width: 100%;
  height: 45px;
  padding: 0 2.5rem 0 .9rem;
  border: 1px solid var(--hairline);
  border-radius: 4px;
  background: rgba(255,255,255,.45);
}
.primary-button {
  min-height: 45px;
  padding: 0 1.15rem;
  border: 0;
  border-radius: 4px;
  color: #f9f7f1;
  background: var(--ink);
  box-shadow: 0 5px 18px rgba(24,40,36,.15);
}
.primary-button:hover { background: var(--river-dark); }
.primary-button:disabled { opacity: .55; cursor: wait; }
.secondary-button {
  min-height: 45px;
  padding: 0 1rem;
  border: 1px solid var(--hairline);
  border-radius: 4px;
  background: rgba(255,255,255,.38);
}
.secondary-button:hover { background: rgba(255,255,255,.72); }
.play-icon { font-size: .72em; margin-right: .45rem; }
.time-control { padding: 0 .2rem .25rem; }
.time-label-row { display: flex; justify-content: space-between; margin-bottom: .65rem; }
input[type="range"] { accent-color: var(--river); width: 100%; }

.visual-shell {
  background: rgba(255,255,255,.52);
  border: 1px solid rgba(255,255,255,.78);
  border-radius: 8px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.visual-heading { padding: 1.5rem 1.7rem 1rem; display: flex; justify-content: space-between; align-items: end; gap: 1rem; }
.visual-heading h2 { margin: 0; font-size: clamp(1.55rem, 3vw, 2.35rem); }
.legend { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 1rem; color: var(--muted); font-size: .72rem; }
.legend span { display: inline-flex; align-items: center; gap: .45rem; }
.legend-line { width: 27px; height: 2px; background: var(--river); display: inline-block; }
.legend-line.approximate { background: repeating-linear-gradient(90deg,var(--clay) 0 5px,transparent 5px 8px); }

.canvas-wrap { min-height: 500px; position: relative; overflow-x: auto; }
.tree-svg, .future-svg { display: block; width: 100%; min-width: 850px; height: auto; }
.tree-edge { fill: none; stroke: var(--river-pale); stroke-width: 3; transition: stroke .2s, stroke-width .2s, opacity .2s; }
.tree-edge.approximate { stroke: rgba(187,96,74,.55); stroke-dasharray: 5 5; }
.tree-edge.hidden-time { opacity: .08; }
.tree-edge.selected { stroke: var(--river-dark); stroke-width: 6; }
.edge-hit { fill: none; stroke: transparent; stroke-width: 20; cursor: pointer; }
.node-dot { fill: var(--paper); stroke: var(--river); stroke-width: 2; transition: transform .2s, opacity .2s; transform-box: fill-box; transform-origin: center; }
.node-group { cursor: pointer; }
.node-group:hover .node-dot, .node-group:focus .node-dot { transform: scale(1.25); }
.node-group.hidden-time { opacity: .18; pointer-events: none; }
.node-form { font-family: Georgia, serif; font-size: 18px; fill: var(--ink); }
.node-language { font-size: 10px; letter-spacing: .11em; text-transform: uppercase; fill: var(--muted); }
.node-year { font-size: 10px; fill: var(--muted); }
.era-line { stroke: var(--hairline); stroke-width: 1; }
.era-label { font-size: 10px; letter-spacing: .08em; fill: var(--muted); }

.detail-drawer { min-height: 112px; border-top: 1px solid var(--hairline); padding: 1.2rem 1.7rem; }
.detail-placeholder { color: var(--muted); font-family: Georgia, serif; font-style: italic; }
.detail-grid { display: grid; grid-template-columns: minmax(160px,.8fr) 1.5fr .7fr; gap: 1.5rem; align-items: start; }
.detail-grid h3 { font-family: Georgia, serif; font-weight: 400; font-size: 1.25rem; margin-bottom: .35rem; }
.detail-grid p { color: var(--muted); line-height: 1.5; margin-bottom: 0; }
.detail-rule { font-size: 1.05rem; color: var(--river-dark); }
.confidence { font-size: .75rem; text-transform: uppercase; letter-spacing: .1em; }

.reading-note { display: grid; grid-template-columns: 42px 1fr; gap: 1rem; max-width: 850px; margin: 1.6rem auto 3.8rem; color: var(--muted); line-height: 1.65; }
.reading-note p { margin: 0; }
.reading-note strong { color: var(--ink); font-weight: 600; }
.note-index { font-family: Georgia, serif; font-style: italic; color: var(--clay); font-size: 1.4rem; }

.basin-control-panel {
  display: grid;
  grid-template-columns: 1.45fr auto 1.2fr minmax(150px, 1fr) minmax(150px, 1fr);
  align-items: end;
  gap: 1rem;
  margin-bottom: 1rem;
}
.ancestor-block { min-width: 220px; }
.ancestor-block span, .ancestor-block strong, .ancestor-block small { display: block; }
.ancestor-block strong { margin: .25rem 0 .15rem; font-family: Georgia, serif; font-size: 1.25rem; font-weight: 400; }
.ancestor-block small { color: var(--muted); line-height: 1.4; }
.future-actions { display: flex; gap: .55rem; }
.compact-range span { display: flex; justify-content: space-between; margin-bottom: .45rem; }
.model-warning { color: var(--clay); font-size: .76rem; margin: 0; }
.future-path { fill: none; stroke-width: 1.05; opacity: .13; transition: opacity .2s, stroke-width .2s; }
.future-path.is-selected { opacity: .58; stroke-width: 1.7; }
.future-path.is-muted { opacity: .06; }
.future-path.basin-0, .future-dot.basin-0 { stroke: var(--river); fill: var(--river); }
.future-path.basin-1, .future-dot.basin-1 { stroke: var(--clay); fill: var(--clay); }
.future-path.basin-2, .future-dot.basin-2 { stroke: var(--gold); fill: var(--gold); }
.future-path.basin-3, .future-dot.basin-3 { stroke: var(--violet); fill: var(--violet); }
.future-path.basin-4, .future-dot.basin-4 { stroke: var(--blue); fill: var(--blue); }
.future-path.basin-5, .future-dot.basin-5 { stroke: var(--moss); fill: var(--moss); }
.basin-zone { fill: rgba(255,255,255,.28); stroke-width: 1.5; }
.basin-zone.basin-0 { stroke: var(--river); }
.basin-zone.basin-1 { stroke: var(--clay); }
.basin-zone.basin-2 { stroke: var(--gold); }
.basin-zone.basin-3 { stroke: var(--violet); }
.basin-zone.basin-4 { stroke: var(--blue); }
.basin-zone.basin-5 { stroke: var(--moss); }
.basin-symbol { font-family: Georgia, serif; font-size: 16px; fill: var(--ink); }
.basin-label { font-size: 9px; letter-spacing: .08em; fill: var(--muted); }
.basin-pct { font-size: 11px; fill: var(--ink); font-weight: 700; }
.future-stage { font-size: 10px; fill: var(--muted); letter-spacing: .1em; }
.future-guide { stroke: var(--hairline); stroke-width: 1; stroke-dasharray: 3 5; }
.future-source { fill: var(--ink); }
.source-invert { fill: var(--paper); }
.future-dot { stroke: none !important; opacity: .88; }
.future-now { stroke: var(--ink); stroke-width: 1; opacity: .55; }
.basin-summary { display: grid; grid-template-columns: repeat(6, 1fr); border-top: 1px solid var(--hairline); }
.basin-stat { appearance: none; text-align: left; border: 0; background: transparent; color: inherit; padding: 1rem 1.05rem; }
.basin-stat + .basin-stat { border-left: 1px solid var(--hairline); }
.basin-stat:hover, .basin-stat.is-selected { background: rgba(255,255,255,.55); box-shadow: inset 0 -3px 0 var(--basin-accent, var(--river)); }
.basin-stat strong, .basin-stat span { display: block; }
.basin-stat strong { font-family: Georgia, serif; font-size: 1rem; font-weight: 400; }
.basin-stat span { color: var(--muted); font-size: .75rem; margin-top: .25rem; }
.basin-stat[data-basin="0"] { --basin-accent: var(--river); }
.basin-stat[data-basin="1"] { --basin-accent: var(--clay); }
.basin-stat[data-basin="2"] { --basin-accent: var(--gold); }
.basin-stat[data-basin="3"] { --basin-accent: var(--violet); }
.basin-stat[data-basin="4"] { --basin-accent: var(--blue); }
.basin-stat[data-basin="5"] { --basin-accent: var(--moss); }
.lineage-detail { border-top: 1px solid var(--hairline); padding: 1.2rem 1.7rem; min-height: 118px; }
.lineage-layout { display: grid; grid-template-columns: minmax(180px,.65fr) 2fr; gap: 1.5rem; align-items: start; }
.lineage-layout h3 { font-family: Georgia, serif; font-weight: 400; margin-bottom: .35rem; }
.lineage-layout p { color: var(--muted); font-size: .82rem; line-height: 1.45; margin-bottom: 0; }
.event-chain { display: flex; align-items: center; flex-wrap: wrap; gap: .45rem; }
.event-step { padding: .48rem .62rem; background: rgba(255,255,255,.52); border-radius: 3px; font-size: .78rem; line-height: 1.3; }
.event-arrow { color: var(--clay); }

.method-section { border-top: 1px solid var(--hairline); border-bottom: 1px solid var(--hairline); margin: 2rem 0 4rem; }
.method-toggle { width: 100%; border: 0; background: transparent; padding: 1.35rem 0; display: flex; justify-content: space-between; font-family: Georgia, serif; font-size: 1.12rem; }
.method-panel { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; padding: .5rem 0 1.8rem; }
.method-panel h3 { font-family: Georgia, serif; font-size: 1rem; font-weight: 400; }
.method-panel p { color: var(--muted); font-size: .88rem; line-height: 1.6; }

footer { width: min(1420px,92vw); margin: 0 auto; padding: 0 0 2.5rem; display: flex; justify-content: space-between; gap: 1rem; color: var(--muted); font-size: .75rem; }

@media (max-width: 980px) {
  .control-strip { grid-template-columns: 1fr 1fr; align-items: end; }
  .basin-control-panel { grid-template-columns: 1fr 1fr; }
  .ancestor-block { grid-column: 1 / -1; }
  .future-actions { align-self: center; }
  .field-label { display: none; }
  .time-control, .compact-range { padding-top: .5rem; }
  .method-panel { grid-template-columns: 1fr; gap: .5rem; }
}

@media (max-width: 640px) {
  main, footer { width: min(94vw, 1420px); }
  .masthead { padding: 0 3vw; }
  .edition { display: none; }
  .intro { padding-top: 3.3rem; }
  h1 { font-size: 3.25rem; }
  .mode-button { padding: .9rem .65rem; gap: .55rem; }
  .mode-number, .mode-button small { display: none; }
  .mode-button strong { font-size: .95rem; }
  .control-strip, .basin-control-panel { grid-template-columns: 1fr; }
  .ancestor-block { grid-column: auto; }
  .future-actions { flex-direction: column; }
  .future-actions button { width: 100%; }
  .primary-button { width: 100%; }
  .visual-heading { align-items: start; flex-direction: column; }
  .legend { justify-content: flex-start; }
  .canvas-wrap { min-height: 420px; }
  .detail-grid { grid-template-columns: 1fr; gap: .7rem; }
  .basin-summary { grid-template-columns: 1fr 1fr; }
  .basin-stat:nth-child(odd) { border-left: 0; }
  .basin-stat:nth-child(n+3) { border-top: 1px solid var(--hairline); }
  .lineage-layout { grid-template-columns: 1fr; }
  footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}