:root {
  --ink: #0f172a;
  --muted: #475569;
  --line: #d7e0ea;
  --paper: #e8eef5;
  --accent: #1d4ed8;
  --navy: #0b3a5b;
  --gold: #c9a227;
  --cfr: #1d4ed8;
  --usc: #0e7490;
  --fr: #b91c1c;
  --iso: #0f766e;
  --iec: #6d28d9;
  --states: #b45309;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", Calibri, sans-serif;
  color: var(--ink);
  background: var(--paper);
}
.top {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  padding: 0.85rem 1.35rem;
  background: linear-gradient(90deg, #0b3a5b, #155e75);
  position: sticky;
  top: 0;
  box-shadow: 0 2px 12px rgba(11, 58, 91, 0.25);
}
.brand {
  font-weight: 700;
  color: #fff;
  text-decoration: none;
  white-space: nowrap;
  letter-spacing: 0.02em;
}
.search { display: flex; gap: 0.4rem; flex: 1; max-width: 32rem; }
.search input {
  flex: 1;
  padding: 0.45rem 0.7rem;
  border: 0;
  border-radius: 6px;
}
.search button, .crumbs a {
  color: var(--accent);
}
.search button {
  border: 0;
  background: var(--gold);
  color: #1a1403;
  font-weight: 600;
  padding: 0.45rem 0.9rem;
  border-radius: 6px;
  cursor: pointer;
}
.search button:hover { filter: brightness(1.05); }
main { padding: 1.35rem; max-width: 1200px; margin: 0 auto; }
main:has(.reader) { max-width: 1440px; }
h1 { font-size: 1.55rem; margin: 0 0 0.35rem; color: var(--navy); }
.sub { color: var(--muted); margin-bottom: 1.1rem; }
.list { list-style: none; padding: 0; margin: 0; background: #fff; border-radius: 10px; overflow: hidden; border: 1px solid var(--line); }
.list li { border-bottom: 1px solid var(--line); }
.list li:last-child { border-bottom: 0; }
.list a {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0.9rem;
  color: var(--ink);
  text-decoration: none;
}
.list a:hover { background: #eff6ff; color: var(--accent); }
.corpus-usc .list a:hover { background: #ecfeff; color: var(--usc); }
.corpus-fr .list a:hover { background: #fef2f2; color: var(--fr); }
.corpus-iso .list a:hover { background: #f0fdfa; color: var(--iso); }
.corpus-iec .list a:hover { background: #f5f3ff; color: var(--iec); }
.corpus-states .list a:hover { background: #fffbeb; color: var(--states); }
.list li.disabled > div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0.9rem;
  color: var(--muted);
  opacity: 0.55;
  cursor: not-allowed;
  filter: grayscale(0.35);
}
.meta { color: var(--muted); font-size: 0.9rem; }
.content {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.25rem;
  line-height: 1.5;
  color: var(--ink);
}
.content img { max-width: 100%; height: auto; }
.content .document-graphic { margin: 0.75rem 0; }
.content img.document-graphic-image {
  max-width: 100%;
  width: auto;
  height: auto;
  display: block;
}
.content section { margin: 0; }
.content p[data-level],
.content div[data-level] { margin: 0.2rem 0; }
.content p[data-level="2"],
.content div[data-level="2"] { margin-left: 1.5rem; }
.content p[data-level="3"],
.content div[data-level="3"] { margin-left: 3rem; }
.content p[data-level="4"],
.content div[data-level="4"] { margin-left: 4.5rem; }
.content p[data-level="5"],
.content div[data-level="5"] { margin-left: 6rem; }
.content p[data-level="6"],
.content div[data-level="6"] { margin-left: 7.5rem; }
.content [class*="qsnum"] { font-weight: 600; margin-right: 0.35rem; }
.content a {
  color: var(--accent);
  text-decoration: underline;
}
.content h1 a, .content h2 a, .content h3 a, .content h4 a {
  color: inherit;
  text-decoration: none;
}
.content ul.ref-list {
  list-style: none;
  padding-left: 0;
  margin: 0.75rem 0 0;
}
.content ul.ref-list li { margin: 0.45rem 0; }
.content ul.ref-list cite { font-style: normal; }
.content .note, .content .example, .content .footnotes {
  margin: 0.75rem 0;
  padding: 0.5rem 0.75rem;
  background: #f8fafc;
  border-left: 4px solid var(--gold);
}
.crumbs { font-size: 0.9rem; margin-bottom: 0.75rem; }
.crumbs a { text-decoration: none; font-weight: 600; }
.empty { color: var(--muted); }
.chooser {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1.1rem;
  max-width: 72rem;
}
@media (max-width: 900px) { .chooser { grid-template-columns: 1fr; } }
.group-title {
  font-size: 1.05rem;
  margin: 1.25rem 0 0.45rem;
  color: var(--navy);
}
.group-title:first-of-type { margin-top: 0; }
.corpus-states .group-title { color: #9a3412; }
.card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.4rem 1.35rem;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  text-decoration: none;
  color: var(--ink);
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
  min-height: 10.5rem;
}
.card strong { font-size: 1.45rem; }
.badge {
  display: inline-block;
  width: fit-content;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
}
.card-cfr { border-top: 6px solid var(--cfr); }
.card-cfr .badge { background: #dbeafe; color: #1e3a8a; }
.card-usc { border-top: 6px solid var(--usc); }
.card-usc .badge { background: #cffafe; color: #155e75; }
.card-fr { border-top: 6px solid var(--fr); }
.card-fr .badge { background: #fee2e2; color: #991b1b; }
.card-iso { border-top: 6px solid var(--iso); }
.card-iso .badge { background: #ccfbf1; color: #115e59; }
.card-iec { border-top: 6px solid var(--iec); }
.card-iec .badge { background: #ede9fe; color: #5b21b6; }
.card-states { border-top: 6px solid var(--states); }
.card-states .badge { background: #ffedd5; color: #9a3412; }
.card:hover:not(.disabled) {
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.12);
}
.card.disabled {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
  filter: grayscale(0.35);
}
.corpus-cfr .top { background: linear-gradient(90deg, #0b3a5b, #1d4ed8); }
.corpus-fr .top { background: linear-gradient(90deg, #7f1d1d, #b91c1c); }
.corpus-usc .top { background: linear-gradient(90deg, #155e75, #0e7490); }
.corpus-iso .top { background: linear-gradient(90deg, #115e59, #0f766e); }
.corpus-iec .top { background: linear-gradient(90deg, #4c1d95, #6d28d9); }
.corpus-states .top { background: linear-gradient(90deg, #9a3412, #d97706); }
.corpus-cfr h1 { color: #1e3a8a; }
.corpus-fr h1 { color: #991b1b; }
.corpus-usc h1 { color: #155e75; }
.corpus-iso h1 { color: #115e59; }
.corpus-iec h1 { color: #5b21b6; }
.corpus-states h1 { color: #9a3412; }
.reader {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
  gap: 1.25rem;
  align-items: start;
}
.toc {
  position: sticky;
  top: 4.6rem;
  max-height: calc(100vh - 5.5rem);
  overflow: auto;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.7rem 0.65rem 0.85rem;
}
.toc-title {
  margin: 0 0.35rem 0.45rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}
.toc ol { list-style: none; margin: 0; padding: 0; }
.toc-tree ol { padding-left: 0.7rem; }
.toc-row {
  display: flex;
  align-items: center;
  gap: 0.1rem;
}
.toc-toggle,
.toc-toggle-spacer {
  flex: 0 0 1rem;
  width: 1rem;
  height: 1rem;
  padding: 0;
  border: 0;
  background: transparent;
  color: #64748b;
  line-height: 1;
}
.toc-toggle {
  cursor: pointer;
  font-size: 0.7rem;
}
.toc-toggle::before { content: "▸"; }
.toc li.branch.open > .toc-row > .toc-toggle::before { content: "▾"; }
.toc li.branch > ol { display: none; }
.toc li.branch.open > ol { display: block; }
.toc a,
.toc .disabled {
  flex: 1;
  min-width: 0;
  display: block;
  padding: 0.22rem 0.35rem;
  color: var(--ink);
  text-decoration: none;
  border-radius: 4px;
  line-height: 1.3;
  font-size: 0.86rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.toc a:hover { background: #eff6ff; color: var(--accent); }
.corpus-fr .toc a:hover { background: #fef2f2; color: var(--fr); }
.corpus-usc .toc a:hover { background: #ecfeff; color: var(--usc); }
.corpus-iso .toc a:hover { background: #f0fdfa; color: var(--iso); }
.corpus-iec .toc a:hover { background: #f5f3ff; color: var(--iec); }
.corpus-states .toc a:hover { background: #fffbeb; color: var(--states); }
.toc a.active {
  background: #1d4ed8;
  color: #fff;
}
.corpus-fr .toc a.active {
  background: #b91c1c;
  color: #fff;
}
.corpus-usc .toc a.active {
  background: #0e7490;
  color: #fff;
}
.corpus-iso .toc a.active {
  background: #0f766e;
  color: #fff;
}
.corpus-iec .toc a.active {
  background: #6d28d9;
  color: #fff;
}
.corpus-states .toc a.active {
  background: #d97706;
  color: #fff;
}
.toc .disabled {
  color: var(--muted);
  opacity: 0.55;
  cursor: not-allowed;
  filter: grayscale(0.35);
}
.toc li.branch > .toc-row a { font-weight: 650; }
.toc-tree ol a { font-weight: 400; }
.content-block { margin-top: 1rem; scroll-margin-top: 5rem; }
.content-block:target .node-heading { color: #1e3a8a; }
.corpus-fr .content-block:target .node-heading { color: #991b1b; }
.corpus-usc .content-block:target .node-heading { color: #155e75; }
.content-block.disabled .node-heading {
  color: var(--muted);
  opacity: 0.55;
  cursor: not-allowed;
  filter: grayscale(0.35);
}
.node-heading {
  font-size: 1.12rem;
  margin: 0 0 0.55rem;
  color: var(--navy);
  text-decoration: none;
}
.reader-body .content { margin-top: 0; scroll-margin-top: 5rem; }
.content .uslm-notes,
.content .uslm-footnotes {
  margin: 0.75rem 0;
  padding: 0.5rem 0.75rem;
  background: #f8fafc;
  border-left: 4px solid var(--gold);
}
.content .uslm-footnoteRef { font-size: 0.75em; }
.content img.uslm-img { max-width: 100%; height: auto; display: block; margin: 0.75rem 0; }
.content .uslm-img-missing {
  display: inline-block;
  padding: 0.2rem 0.4rem;
  background: #f1f5f9;
  color: var(--muted);
  font-size: 0.85rem;
}
.corpus-iso .content-block:target .node-heading { color: #115e59; }
.corpus-iec .content-block:target .node-heading { color: #5b21b6; }
.corpus-states .content-block:target .node-heading { color: #9a3412; }
@media (max-width: 860px) {
  .reader { grid-template-columns: 1fr; }
  .toc { position: static; max-height: 16rem; }
}