/* =========================================================
   1. BRAND / TOP BAR
   ========================================================= */

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  color: inherit;
  text-decoration: none;
}

.brand-link:focus {
  outline: 2px solid rgba(26, 188, 156, 0.45);
  outline-offset: 3px;
  border-radius: 12px;
}

.logo {
  width: 38px;
  height: 38px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(26, 188, 156, 0.10);
  color: var(--primary);
  box-shadow:
    inset 0 0 0 1px rgba(255, 255, 255, 0.03),
    0 10px 28px rgba(0, 0, 0, 0.28);
}

.logo svg {
  width: 26px;
  height: 26px;
  display: block;
}

.title {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.title h1 {
  margin: 0;
  font-size: 14px;
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: 0.2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.title h1 strong {
  font-weight: 850;
}

.title h1 span {
  margin-left: 4px;
  color: var(--muted);
  font-weight: 500;
}

.title p {
  margin: 0;
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}


/* =========================================================
   2. LANGUAGE TOGGLE
   ========================================================= */

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.18);
  user-select: none;
  font-size: 12px;
}

.lang-toggle a {
  padding: 6px 8px;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--muted);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-decoration: none;
}

.lang-toggle a:hover {
  color: var(--text);
  border-color: rgba(26, 188, 156, 0.35);
  background: rgba(26, 188, 156, 0.08);
}

.lang-toggle a.active {
  color: var(--text);
  border-color: rgba(26, 188, 156, 0.45);
  background: rgba(26, 188, 156, 0.12);
}

.lang-toggle .sep {
  color: rgba(154, 160, 166, 0.7);
}


/* =========================================================
   3. SIDEBAR / MAIN NAVIGATION
   ========================================================= */

nav {
  padding: 8px;
  overflow: auto;
}

.nav-section {
  margin: 6px 0 10px;
}

.nav-label {
  padding: 10px 10px 6px;
  color: var(--muted);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.09em;
}

/* Menu container */

details.menu {
  margin: 6px 0;
  overflow: hidden;
  border: 1px solid transparent;
  border-radius: 14px;
  background: transparent;
}

details.menu[open] {
  border-color: var(--border-strong);
  background: rgba(26, 188, 156, 0.06);
}

/* Menu title */

summary.menu-title {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px;
  list-style: none;
  cursor: pointer;
  user-select: none;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.015);
  transition: background 0.15s ease, border-color 0.15s ease;
}

summary.menu-title::-webkit-details-marker {
  display: none;
}

summary.menu-title:hover {
  background: rgba(26, 188, 156, 0.06);
  border-color: var(--border-strong);
}

details.menu[open] > summary.menu-title {
  background: rgba(26, 188, 156, 0.10);
  border-color: var(--border-strong);
}

/* Menu title structure */

.menu-left {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.menu-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.menu-text strong {
  font-size: 13px;
  font-weight: 750;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.menu-text span {
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Menu icons */

.icon {
  width: 26px;
  height: 26px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(26, 188, 156, 0.08);
  color: var(--primary);
}

.icon svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
}

details.menu[open] .icon {
  background: rgba(26, 188, 156, 0.14);
}

.chev {
  width: 26px;
  height: 26px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.2);
  transition: transform 0.15s ease;
}

details.menu[open] .chev {
  transform: rotate(90deg);
}

/* Submenu */

.submenu {
  position: relative;
  z-index: 2;
  display: none;
  gap: 6px;
  padding: 6px 10px 12px;
}

details.menu[open] > .submenu {
  display: grid;
}

.submenu a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 10px;
  border: 1px solid transparent;
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.18);
  color: var(--text);
  text-decoration: none;
}

.submenu a:hover {
  border-color: var(--border-strong);
  background: rgba(26, 188, 156, 0.08);
}

.submenu a small {
  font-size: 12px;
  color: var(--muted);
}

.series-item {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
}

.submenu-title {
  line-height: 1.3;
}

.submenu-meta {
  white-space: nowrap;
  font-size: 12px;
  color: var(--muted);
  opacity: 0.75;
}

/* Sidebar preload behavior */

html.nav-preload details.menu,
html.nav-preload summary.menu-title,
html.nav-preload .submenu,
html.nav-preload .submenu a,
html.nav-preload .chev {
  transition: none !important;
}

html.nav-preload nav[aria-label="Main navigation"] {
  visibility: hidden;
}

/* Sidebar footer */

.sidebar-footer {
  margin-top: auto;
  padding: 12px 16px;
  border-top: 1px solid var(--border-strong);
  color: var(--muted);
  font-size: 12px;
}


/* =========================================================
   4. MAIN HEADER / PAGE CONTENT
   ========================================================= */

.main-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 14px;
  padding: 18px 18px 14px;
  border-bottom: 1px solid var(--border-strong);
}

.main-header h2 {
  margin: 0;
  font-size: 19px;
  font-weight: 850;
  letter-spacing: -0.2px;
}

.main-header p {
  margin: 6px 0 0;
  max-width: 70ch;
  color: var(--muted);
  line-height: 1.6;
  font-size: 14.5px;
}

.content {
  display: grid;
  gap: 14px;
  padding: 18px;
}


/* =========================================================
   5. CARDS / LAYOUTS
   ========================================================= */

.card {
  min-width: 0;
  padding: 14px;
  border: 1px solid var(--border);
  border-top: 1px solid var(--border-strong);
  border-radius: 16px;
  background: rgba(0, 0, 0, 0.18);
}

.card h3 {
  margin: 0 0 10px;
  font-size: 14.5px;
  font-weight: 850;
  letter-spacing: -0.2px;
}

.card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
  font-size: 15.3px;
}

.card p + p {
  margin-top: 12px;
}

.card-sub {
  margin-top: 10px;
  margin-bottom: 16px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Card containers */

.cards-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  width: 100%;
  max-width: 100%;
  align-items: start;
}

.cards-grid .card {
  height: 100%;
}

.cards-stack {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

/* Full-width transition card */

.card.full {
  grid-column: 1 / -1;
  padding-left: 1.25rem;
  border-left: 4px solid #4da3ff;
}

.card.full a,
.card.full a:visited {
  color: #4da3ff;
  font-weight: 600;
  text-decoration: none;
}

.card.full a:hover {
  color: #ffffff;
  text-decoration: underline;
}

/* =========================================================
   6. SEARCH INDEX / FAMILY CARDS
   ========================================================= */

.index-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.search-section {
  position: relative;
  min-width: 0;
  overflow: hidden;
  padding: 16px 14px 14px 18px;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.02);
}

.search-section::before {
  content: "";
  position: absolute;
  top: 16px;
  bottom: 16px;
  left: 0;
  width: 4px;
  border-radius: 8px;
  background: linear-gradient(
    to bottom,
    rgba(26, 188, 156, 0.9),
    rgba(26, 188, 156, 0.3)
  );
}

.search-section h4 {
  margin: 0 0 14px;
  color: var(--text);
  font-size: 13.5px;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.search-section p {
  margin-bottom: 16px;
}

/* Search list */

.search-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.search-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-width: 0;
}

.search-list {
  list-style: none;
  display: grid;
  gap: 6px;
  margin: 0;
  padding: 0;
}

.search-list li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-width: 0;
}

.search-list a {
  display: inline-block;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--text);
  font-weight: 650;
  text-decoration: none;
}

.search-list a:hover {
  color: var(--primary);
}

/*Search list scoped*/
.search-index-page .search-list{
  list-style:none;
  margin:14px 0 0;
  padding:0;
  display:grid;
  gap:10px;
}

.search-index-page .search-list li{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
}

.search-index-page .search-list li a{
  display:flex;
  align-items:center;
  gap:8px;
  color:var(--text);
  text-decoration:none;
  font-weight:600;
}

.search-index-page .search-list li a::before{
  content:"→";
  color:var(--primary);
  opacity:.85;;
}

.search-index-page .search-list li a:hover{
  color:var(--primary);
  text-decoration:underline;
}

/* Construction badge */

.badge-construction {
  flex: 0 0 auto;
  padding: 3px 8px;
  border: 1px solid rgba(26, 188, 156, 0.35);
  border-radius: 999px;
  background: rgba(26, 188, 156, 0.08);
  color: var(--text);
  font-size: 11px;
  font-weight: 800;
}


/* =========================================================
   7. INLINE CODE
   ========================================================= */

code {
  padding: 2px 6px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.25);
  color: var(--text);
  font-size: 0.95em;
}


/* =========================================================
   8. TEXT / NOTE / MATH BLOCKS
   ========================================================= */

.math-quote {
  margin: 0;
  padding: 14px;
  border-left: 3px solid rgba(26, 188, 156, 0.55);
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.14);
}

.math-quote p {
  margin: 0 0 10px;
  line-height: 1.7;
}

.math-note {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.math-list {
  display: grid;
  gap: 8px;
  margin: 12px 0;
  padding-left: 22px;
}

.math-list li {
  color: var(--muted);
  line-height: 1.7;
}

.callout {
  margin-top: 12px;
  padding: 10px 12px;
  border-left: 2px solid rgba(26, 188, 156, 0.7);
  border-radius: 10px;
  background: rgba(26, 188, 156, 0.05);
  color: var(--text);
  font-weight: 600;
}

.note {
  margin-top: 14px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  color: rgba(154, 160, 166, 0.9);
  font-style: italic;
  font-size: 12.5px;
}

.math {
  margin: 14px 0 0;
  color: var(--text);
  line-height: 1.75;
  font-size: 15px;
}

.card .math:first-of-type {
  margin-top: 8px;
}

.katex-inline {
  color: var(--text);
  font-weight: 600;
}

.math-block {
  margin-top: 16px;
  padding: 10px 12px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-left: 3px solid rgba(26, 188, 156, 0.55);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.12);
}

.math-block .katex-display {
  margin: 0;
}

.math-block--ore {
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.math-block--ore::-webkit-scrollbar {
  height: 0;
}


/* =========================================================
   9. GRAPH META / ARC DETAILS
   ========================================================= */

.graph-meta {
  margin-top: 14px;
  padding: 10px 12px;
  border-top: 1px solid var(--border);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.12);
}

.arc-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.arc-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 10px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.16);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.2;
  white-space: nowrap;
}

.arc-chip strong {
  color: var(--text);
  font-weight: 750;
}

.arc-chip em {
  color: rgba(231, 76, 60, 0.90);
  font-style: normal;
  font-weight: 800;
}

.arc-list {
  display: grid;
  gap: 6px;
  margin: 8px 0 0;
  padding-left: 18px;
}

.arc-list li {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.arc-list li strong {
  color: var(--text);
  font-weight: 700;
}

.arc-list li span {
  margin-left: 4px;
  color: rgba(231, 76, 60, 0.9);
  font-weight: 700;
}


/* =========================================================
   10. GRAPH / EXAMPLE LAYOUTS
   ========================================================= */

/* Adjacency layout */

.adj-card {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 18px;
  align-items: start;
}

.adj-graph {
  margin: 0;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.12);
}

.adj-graph svg {
  width: 100%;
  height: auto;
  display: block;
}

.adj-caption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 12.5px;
}

.adj-matrix .adj-mathblock {
  margin-top: 12px;
  padding: 10px 12px;
  border-left: 3px solid rgba(26, 188, 156, 0.55);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.12);
}

/* Example graph layout */

.example-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 18px;
  align-items: start;
  width: 100%;
  max-width: 100%;
}

.example-graph {
  min-width: 0;
  padding: 12px;
  border: 1px solid var(--border);
  border-top: 1px solid var(--border-strong);
  border-radius: 16px;
  background: rgba(0, 0, 0, 0.18);
}

.example-graph svg {
  width: 100%;
  max-width: 520px;
  height: auto;
  display: block;
  margin: 0 auto;
}


/* =========================================================
   11. FOOTER
   ========================================================= */

.main-footer {
  margin-top: auto;
  padding: 12px 18px;
  border-top: 1px solid var(--border-strong);
  background:
    radial-gradient(900px 220px at 20% 120%, rgba(26, 188, 156, 0.18), transparent 60%),
    radial-gradient(700px 220px at 80% 120%, rgba(22, 160, 133, 0.14), transparent 55%),
    rgba(0, 0, 0, 0.12);
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}


/* =========================================================
   12. RESPONSIVE
   ========================================================= */

@media (max-width: 980px) {
  .index-grid {
    grid-template-columns: 1fr;
  }

  .search-list a {
    white-space: normal;
  }
}

@media (max-width: 900px) {
  .cards-grid {
    grid-template-columns: 1fr;
  }

  .adj-card,
  .example-grid {
    grid-template-columns: 1fr;
  }

  .example-graph {
    padding: 10px;
  }

  .math-block {
    padding: 10px;
  }
}

@media (max-width: 600px) {
  .example-graph svg {
    max-width: 340px;
    max-height: 220px;
  }
}

@media (max-width: 420px) {
  .example-graph svg {
    max-width: 300px;
    max-height: 200px;
  }
}