:root {
  --paper: #fafaf7;
  --surface: #ffffff;
  --surface-2: #f2f2ed;
  --ink: #1d1d1a;
  --muted: #686861;
  --line: #d2d2ca;
  --line-dark: #9b9b92;
  --accent: #a30000;
  --focus: #a30000;
  --serif: Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

:root[data-theme="dark"] {
  --paper: #151613;
  --surface: #1b1c18;
  --surface-2: #22231f;
  --ink: #e9e9e2;
  --muted: #aaa9a0;
  --line: #3e3f39;
  --line-dark: #71726a;
  --accent: #ff756d;
  --focus: #ff756d;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body {
  min-height: 100%;
  margin: 0;
  background: var(--paper);
  color: var(--ink);
}

body {
  font-family: var(--sans);
  font-size: 14px;
  line-height: 1.46;
  -webkit-font-smoothing: antialiased;
}

button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
h1, h2, h3, h4, p { margin-top: 0; }
h1, h2, h3 { font-family: var(--serif); font-weight: 400; }

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

button {
  border: 1px solid var(--line-dark);
  border-radius: 0;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
}

button:hover { border-color: var(--ink); }

button:disabled {
  cursor: default;
  opacity: 0.42;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
summary:focus-visible,
.map-scroll:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  align-items: end;
  padding: 16px 22px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.title-block { min-width: 0; }

.back-link {
  display: inline-block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 11px;
}

h1 {
  margin-bottom: 0;
  font-size: clamp(27px, 3vw, 38px);
  line-height: 1;
}

.intro {
  max-width: 760px;
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 12.5px;
}

.header-controls {
  display: flex;
  gap: 8px;
  align-items: center;
  flex: 0 0 auto;
}

.classification-key {
  margin: 14px 18px 18px;
  border: 1px solid var(--line-dark);
  background: var(--surface);
}

.classification-key > header {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(260px, .75fr);
  gap: 20px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
}

.classification-key h2 {
  margin: 0 0 3px;
  font-size: 18px;
}

.classification-key p {
  margin: 0;
  color: var(--muted);
  font-size: 11.5px;
}

.classification-key .classification-example {
  align-self: end;
  color: var(--ink);
}

.classification-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.classification-grid a {
  min-width: 0;
  padding: 11px 13px 12px;
  border-right: 1px solid var(--line);
  color: var(--ink);
  text-decoration: none;
}

.classification-grid a:last-child { border-right: 0; }
.classification-grid a:hover, .classification-grid a:focus-visible { background: var(--surface-2); }
.classification-grid span, .classification-grid small { display: block; }
.classification-grid span {
  margin-bottom: 5px;
  color: var(--accent);
  font-family: var(--mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: .045em;
}
.classification-grid strong { font-family: var(--serif); font-size: 16px; font-weight: 400; }
.classification-grid small { margin-top: 4px; color: var(--muted); font-size: 10.5px; line-height: 1.35; }

.classification-key .classification-rule {
  padding: 9px 14px 10px;
  border-top: 1px solid var(--line);
  color: var(--ink);
}

#theme-toggle {
  min-height: 34px;
  padding: 5px 9px;
}

.tree-tools {
  padding: 12px 18px 10px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}

.tree-tools > div:first-child {
  display: flex;
  gap: 16px;
  align-items: baseline;
}

.tree-tools h2 {
  margin: 0;
  font-size: 20px;
}

.tree-tools p {
  margin: 0;
  color: var(--muted);
  font-size: 11.5px;
}

.tool-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: end;
  margin-top: 10px;
}

.search-box {
  position: relative;
  width: min(480px, 100%);
}

.search-box > label {
  display: block;
  margin-bottom: 3px;
  color: var(--muted);
  font-size: 10px;
}

.search-input-row { display: flex; }

.search-input-row input {
  min-width: 0;
  width: 100%;
  min-height: 33px;
  padding: 5px 8px;
  border: 1px solid var(--line-dark);
  border-right: 0;
  border-radius: 0;
  background: var(--paper);
  color: var(--ink);
}

.search-input-row button,
.tree-actions button {
  min-height: 33px;
  padding: 5px 9px;
  white-space: nowrap;
}

.search-results {
  position: absolute;
  z-index: 20;
  top: calc(100% + 3px);
  width: 100%;
  max-height: 330px;
  overflow-y: auto;
  border: 1px solid var(--line-dark);
  background: var(--surface);
}

.search-results button {
  display: block;
  width: 100%;
  padding: 7px 9px;
  border: 0;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.search-results button:last-child { border-bottom: 0; }
.search-results button:hover { background: var(--surface-2); }
.search-results strong { display: block; font-weight: 600; }
.search-results span { display: block; color: var(--muted); font-size: 10px; }
.search-results p { margin: 0; padding: 8px; }

.tree-actions { display: flex; gap: 6px; }

.route-switch {
  display: flex;
  gap: 5px;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 9px;
}

.route-label {
  margin-right: 3px;
  color: var(--muted);
  font-size: 10px;
}

.route-switch button {
  padding: 3px 7px;
  border-color: var(--line);
  color: var(--muted);
  font-size: 10px;
}

.route-switch button[aria-pressed="true"] {
  border-color: var(--ink);
  color: var(--ink);
}

.map-scroll {
  position: relative;
  height: max(540px, 64vh);
  overflow: auto;
  overscroll-behavior: contain;
  border-bottom: 1px solid var(--line);
  background: var(--paper);
  scrollbar-color: var(--line-dark) transparent;
}

.map-canvas {
  position: relative;
  min-width: 100%;
  min-height: 100%;
}

.edge-layer,
.node-layer {
  position: absolute;
  inset: 0;
}

.edge-layer {
  display: block;
  overflow: visible;
  pointer-events: none;
}

.map-edge {
  fill: none;
  stroke: var(--line-dark);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
}

.map-edge.index-edge {
  stroke-dasharray: 4 4;
  opacity: .72;
}

.map-edge.route-edge { stroke: var(--ink); }
.map-edge.selected-edge { stroke: var(--accent); stroke-width: 1.5; }

.map-node {
  position: absolute;
  width: 212px;
  height: 80px;
  transform: translate(-50%, -50%);
  padding: 8px 25px 8px 10px;
  border-color: var(--line-dark);
  background: var(--surface);
  text-align: left;
}

.map-node:hover { border-color: var(--ink); }

.map-node.index-node { border-style: dashed; }

.map-node .node-kind {
  display: block;
  min-height: 19px;
  margin-bottom: 3px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.2;
}

.map-node .node-label {
  display: block;
  font-family: var(--serif);
  font-size: 14.5px;
  line-height: 1.14;
}

.map-node .branch-mark {
  position: absolute;
  top: 50%;
  right: 8px;
  transform: translateY(-50%);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 14px;
}

.map-node.expanded { border-color: var(--ink); }
.map-node.route-node { border-bottom-color: var(--ink); }

.map-node[aria-selected="true"] {
  z-index: 2;
  border: 2px solid var(--accent);
  padding: 7px 24px 7px 9px;
}

.map-node.index-node[aria-selected="true"] { border-style: dashed; }

.map-node.root-node {
  border-color: var(--ink);
  background: var(--ink);
  color: var(--surface);
}

.map-node.root-node .node-kind,
.map-node.root-node .branch-mark { color: var(--line); }

.map-instructions,
.swipe-hint {
  margin: 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9.5px;
}

.map-instructions { padding: 7px 18px; }
.swipe-hint { display: none; padding: 0 18px 7px; }

.detail-panel {
  max-width: 1040px;
  margin: 28px auto 48px;
  padding: 0 22px;
}

.breadcrumbs {
  display: flex;
  gap: 4px 9px;
  flex-wrap: wrap;
  margin-bottom: 10px;
  color: var(--muted);
}

.breadcrumbs button {
  padding: 0;
  border: 0;
  color: var(--muted);
  font-size: 10.5px;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.breadcrumbs button::after { margin-left: 9px; content: "/"; color: var(--line-dark); }
.breadcrumbs button:last-child { color: var(--ink); cursor: default; text-decoration: none; }
.breadcrumbs button:last-child::after { content: ""; margin: 0; }

.reference-marker {
  color: var(--ink);
  font-family: var(--mono);
  font-size: 10px;
}

.detail-heading {
  padding-bottom: 14px;
  border-bottom: 1px solid var(--ink);
}

.kind-badge,
.period-label {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9px;
}

.period-label::before { content: " · "; }

.detail-title-row {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: baseline;
  margin-top: 5px;
}

.detail-title-row h2 {
  margin: 0;
  font-size: clamp(27px, 4vw, 40px);
  line-height: 1;
}

#primary-source {
  flex: 0 1 auto;
  font-size: 11px;
  text-align: right;
}

.detail-question {
  max-width: 760px;
  margin: 8px 0 0;
  color: var(--muted);
  font-family: var(--serif);
  font-size: 16px;
}

.detail-grid { border-bottom: 1px solid var(--line); }

.summary-section {
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.summary-section h3,
.case-sources h3 {
  margin: 0 0 5px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.summary-section > p { max-width: 820px; margin-bottom: 0; }

.formal-definition {
  max-width: 100% !important;
  margin-top: 10px;
  border-left: 2px solid var(--ink);
  background: var(--surface-2);
}

.formal-definition summary {
  padding: 7px 10px;
  cursor: pointer;
  font-size: 11px;
}

.formal-definition[open] { padding-bottom: 8px; }

.formal-definition span {
  display: block;
  margin: 0 10px 3px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 8.5px;
  text-transform: uppercase;
}

.formal-definition code {
  display: block;
  padding: 0 10px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 12px;
  white-space: nowrap;
}

.formal-definition small {
  display: block;
  margin: 6px 10px 0;
  color: var(--muted);
  font-size: 9.5px;
}

.split-rule {
  margin-top: 13px;
  padding-top: 11px;
  border-top: 1px solid var(--line-dark);
}

.split-rule > header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: baseline;
}

.split-rule > header h3 { margin-bottom: 0; }

#split-status {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 8.5px;
  text-align: right;
}

.split-rule dl {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  margin: 8px 0 0;
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.split-rule dl > div {
  min-width: 0;
  padding: 8px 9px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.split-rule dt {
  margin-bottom: 3px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 8px;
  text-transform: uppercase;
}

.split-rule dd {
  margin: 0;
  font-size: 11.5px;
}

#split-values { font-family: var(--mono); font-size: 10px; }
#split-caveat { margin: 8px 0 0; color: var(--muted); font-size: 10.5px; }

#split-sources {
  display: flex;
  gap: 4px 14px;
  flex-wrap: wrap;
  margin: 7px 0 0;
  padding: 0;
  list-style: none;
  font-size: 10px;
}

.detail-fold {
  border-bottom: 1px solid var(--line);
}

.detail-fold:last-child { border-bottom: 0; }

.detail-fold > summary {
  padding: 8px 0;
  color: var(--ink);
  cursor: pointer;
  font-size: 12px;
  list-style-position: outside;
}

.detail-fold > summary span { color: var(--muted); font-family: var(--mono); font-size: 9px; }
.detail-fold[open] > summary { border-bottom: 1px solid var(--line); }

.detail-fold > div,
.detail-fold > ul {
  max-width: 860px;
  margin: 0;
  padding: 9px 0 10px;
}

.detail-fold > ul { padding-left: 18px; }
.detail-fold li { margin: 4px 0; }

.copy-item {
  margin: 0;
  padding: 7px 0;
  border-bottom: 1px dotted var(--line);
}

.copy-item:last-child { border-bottom: 0; }

.related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.related-links a {
  padding: 4px 7px;
  border: 1px solid var(--line-dark);
  color: var(--accent);
  font-size: 10.5px;
}

.sources-section li { font-size: 11px; }

.case-reference-list {
  max-width: 100% !important;
  padding: 0 !important;
}

.case-reference {
  display: block;
  width: 100%;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  text-align: left;
  text-decoration: none;
}

.case-reference:last-child { border-bottom: 0; }
.case-reference:hover strong { color: var(--accent); }

.case-reference-heading {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: baseline;
}

.case-reference-heading strong {
  color: var(--accent);
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 400;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.case-reference-heading > span { color: var(--muted); font-family: var(--mono); font-size: 9px; }
.case-reference-use { display: block; margin-top: 3px; color: var(--muted); font-size: 11.5px; }

.case-record {
  margin-top: 34px;
  padding-top: 18px;
  border-top: 2px solid var(--ink);
  scroll-margin-top: 18px;
}

.case-record-heading {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: start;
}

.case-kind,
.case-relation-type {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9px;
  text-transform: uppercase;
}

.case-record-heading h3 { margin: 3px 0 0; font-size: clamp(25px, 3vw, 34px); }
.case-record-heading button { padding: 4px 8px; }
.case-purpose { max-width: 800px; margin: 10px 0 17px; font-family: var(--serif); font-size: 16px; }

.case-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-dark);
  border-left: 1px solid var(--line-dark);
}

.case-facts section {
  padding: 12px;
  border-right: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
}

.case-record h4,
.case-response h4 {
  margin: 0 0 4px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 400;
  text-transform: uppercase;
}

.case-record p { margin-bottom: 0; }
.case-connections { margin-top: 20px; }
.case-connections > h4 { margin-bottom: 6px; }

.case-relation {
  display: grid;
  grid-template-columns: minmax(190px, 0.7fr) minmax(0, 2fr);
  gap: 18px;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}

.case-relation > div { display: flex; flex-direction: column; align-items: start; gap: 2px; }
.case-relation a { color: var(--accent); text-align: left; }
.case-relation p { color: var(--muted); font-size: 11.5px; }

.case-fold { border-top: 1px solid var(--line-dark); }
.case-fold:last-child { border-bottom: 1px solid var(--line-dark); }
.case-fold > summary { padding: 9px 0; cursor: pointer; font-size: 12px; }
.case-fold > summary span { color: var(--muted); font-family: var(--mono); font-size: 9px; }
.case-fold > ul { margin: 0; padding: 10px 0 10px 18px; }
.case-fold > ul li { margin: 4px 0; font-size: 11px; }

.case-response-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-dark);
  border-left: 1px solid var(--line-dark);
}

.case-response {
  min-width: 0;
  padding: 12px;
  border-right: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
}

.case-response h3 { margin-bottom: 7px; font-size: 18px; }
.case-response h4 { margin-top: 10px; }
.case-response p { font-size: 12px; }
.case-response .response-answer { font-family: var(--serif); font-size: 14px; }
.case-response .response-worry { color: var(--muted); }
.case-response > a { display: inline-block; margin-top: 10px; font-size: 10px; }

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

noscript {
  display: block;
  margin: 18px;
  padding: 10px;
  border: 1px solid var(--line-dark);
}

@media (max-width: 820px) {
  .topbar { align-items: start; flex-direction: column; gap: 12px; }
  .tree-tools > div:first-child { align-items: start; flex-direction: column; gap: 2px; }
  .tool-row { align-items: stretch; flex-direction: column; }
  .tree-actions { justify-content: flex-start; }
  .map-scroll { height: 570px; }
  .swipe-hint { display: block; }
  .detail-title-row { align-items: start; flex-direction: column; gap: 7px; }
  #primary-source { text-align: left; }
  .case-response-list { grid-template-columns: 1fr; }
  .classification-key > header { grid-template-columns: 1fr; gap: 7px; }
  .classification-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .split-rule dl { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .topbar { padding: 14px; }
  .header-controls { width: 100%; align-items: stretch; flex-direction: column; }
  #theme-toggle { width: 100%; }
  .tree-tools { padding-right: 12px; padding-left: 12px; }
  .tree-actions { display: grid; grid-template-columns: 1fr 1fr; }
  .map-instructions, .swipe-hint { padding-right: 12px; padding-left: 12px; }
  .detail-panel { margin-top: 22px; padding-right: 14px; padding-left: 14px; }
  .case-facts, .case-relation { grid-template-columns: 1fr; }
  .case-relation { gap: 4px; }
  .classification-key { margin: 10px 12px 14px; }
  .classification-grid { grid-template-columns: 1fr; }
  .classification-grid a { border-right: 0; border-bottom: 1px solid var(--line); }
  .classification-grid a:last-child { border-bottom: 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}