:root {
  color-scheme: light;
  --page: #f9f9f7;
  --ink: #161616;
  --surface: #ffffff;
  --muted: #60635c;
  --rule: #b8bbb0;
  --soft-rule: #d5d5d0;
  --hover: #e9e9e4;
  --selected: #171717;
  --on-selected: #ffffff;
  --panel: #f1f2ed;
  --accent: #236447;
  --accent-surface: #edf4ef;
}
:root[data-theme='dark'] {
  color-scheme: dark;
  --page: #181a18;
  --ink: #e9e9e2;
  --surface: #20241f;
  --muted: #afb5a8;
  --rule: #596051;
  --soft-rule: #3e453a;
  --hover: #2e342b;
  --selected: #e9e9e2;
  --on-selected: #181a18;
  --panel: #22281f;
  --accent: #8fbaa5;
  --accent-surface: #253b30;
}
:root, body, .family-page { background: var(--page); color: var(--ink); }
body > header, .family-page > header { background: var(--page); border-color: var(--ink); }
body > footer, #main > footer { border-color: var(--ink); color: var(--muted); }
button, input, textarea, select, .local, aside, .panel, .badge, .rule,
.editor-block, .source, .category-group, .family-inline, .article-return,
.reading-guide, .family-page > footer, nav, .records { border-color: var(--rule); }
.passage, aside .lead, .feedback, details, li { border-color: var(--soft-rule); }
input, textarea, select { background: var(--surface); color: var(--ink); }
input::placeholder, textarea::placeholder { color: var(--muted); opacity: 1; }
input[type='checkbox'] { accent-color: var(--accent); }
button:hover { background: var(--hover); }
button.primary, button.active { background: var(--selected); color: var(--on-selected); border-color: var(--selected); }
aside .lead.active small { color: var(--on-selected); }
.meta, .fine, .empty, aside .lead small, .category-group summary span,
figcaption, .document-figure figcaption { color: var(--muted); }
.passage.selected, .focus { border-left-color: var(--ink); }
.document-figure { background: var(--surface); border-color: var(--rule); }
.document-figure figcaption { border-color: var(--soft-rule); }
/* Original files stay intact; reverse patent illustrations only for dark screens. */
.document-figure img, figure img { background: #fff; color-scheme: light; }
@media screen {
  :root[data-theme='dark'] :is(.document-figure img, figure a[href*='.pdf'] img) {
    filter: invert(1);
  }
}
.ft { --ft-ink: var(--ink); --ft-rule: var(--rule); --ft-blue: var(--accent); }
.ft button:hover, .ft-branches button[aria-pressed='true'] { background: var(--hover); }
.ft-companies button[aria-pressed='true'] { background: var(--selected); color: var(--on-selected); }
.ft .ft-eyebrow, .ft-branches button span, .ft-graph-heading p, .ft-legend,
.ft-inspector dt, .ft-inspector .ft-muted, .ft-publication small,
.ft .ft-scope, .family-page .family-kicker, .ft-pct-context dt { color: var(--muted); }
.ft-inspector { background: var(--panel); border-color: var(--ink); }
.ft-pct-context { background: var(--accent-surface); border-color: var(--rule); border-left-color: var(--accent); }
.ft-focuses button[aria-pressed='true'] { background: var(--accent-surface); border-color: var(--accent); }
/* Theme the embedded platform SVG without changing its original source file. */
.ft { --ft-canvas-bg: #f5f5f7; }
.ft .ft-canvas { background: var(--ft-canvas-bg); color-scheme: light; }
.ft .ft-native {
  --bg: var(--ft-canvas-bg); --border: #d1d1d6; --text: #1a1a2e;
  --text-muted: #6e6e80; --blue: var(--accent);
}
@media screen {
  :root[data-theme='dark'] .ft { --ft-canvas-bg: #181c18; }
  :root[data-theme='dark'] .ft .ft-canvas {
    color-scheme: dark;
    scrollbar-color: #899380 var(--ft-canvas-bg);
  }
  :root[data-theme='dark'] .ft .ft-native {
    --border: #596456; --text: #e9e9e2; --text-muted: #c0c8b9; --blue: var(--accent);
  }
  /* Keep lines legible when the whole family is scaled down. */
  :root[data-theme='dark'] .ft-native :is(.year, .link, .member, .event) > line {
    vector-effect: non-scaling-stroke;
  }
  :root[data-theme='dark'] .ft-native :is(.member > line, .event > line, .event > text, .branch > line, .branch > text) {
    filter: brightness(1.8) saturate(.75);
  }
  :root[data-theme='dark'] .ft-native .branch > line { opacity: .5; }
  :root[data-theme='dark'] .ft-native .ft-featured > rect:first-of-type {
    stroke: var(--accent);
  }
  :root[data-theme='dark'] .ft-native .ft-related > line {
    stroke: var(--accent); filter: none;
  }
  :root[data-theme='dark'] .ft-native .event.ft-hover > line {
    stroke: #fff; filter: none;
  }
}
.ft-focus-key { border-color: var(--ink); }
.reading-guide li { border-color: var(--soft-rule); }
.reading-guide .reading-guide-label, .reading-guide-number,
.reading-guide-description, .article-body .part-marker, .part-marker { color: var(--muted); }
.article-body .part-marker, .part-marker { border-color: var(--ink); }
.reading-guide a:focus-visible, a:focus-visible, summary:focus-visible { outline-color: var(--accent); }
.article-return > a { background: var(--surface); border-color: var(--rule); }
.article-return > a:hover { background: var(--accent-surface); }
.appearance-control {
  display: flex; align-items: center; gap: 9px; flex-shrink: 0;
  margin: 0; font: 12px/1.4 'Courier New', monospace; color: var(--muted);
}
.appearance-control select {
  width: auto; min-width: 103px; margin: 0; padding: 8px 26px 8px 10px;
  font: 13px/1.4 'Courier New', monospace; border: 1px solid var(--rule);
  background: var(--surface); color: var(--ink); border-radius: 0; cursor: pointer;
}
.appearance-control select:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
@media (max-width: 700px) {
  .appearance-control { margin-left: auto; }
  .appearance-control span { font-size: 11px; }
}
@media print {
  :root[data-theme], :root {
    color-scheme: light;
    --page: #fff; --ink: #161616; --surface: #fff; --muted: #505049;
    --rule: #aaa; --soft-rule: #ddd; --panel: #f1f2ed;
    --selected: #171717; --on-selected: #fff; --accent: #236447; --accent-surface: #edf4ef;
  }
  .appearance-control { display: none; }
}