:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #f9fbff;
  --text: #1b2737;
  --muted: #5e6d82;
  --line: #d7e0ed;
  --brand: #0972d3;
  --brand-strong: #025cb1;
  --accent: #eef5ff;
  --shadow: 0 14px 36px rgba(18, 40, 68, 0.08);
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: "Segoe UI", Inter, Roboto, Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d141f;
    --surface: #111b2a;
    --surface-soft: #0f1927;
    --text: #e8f0fd;
    --muted: #9cb0ca;
    --line: #24354d;
    --brand: #4ea1ff;
    --brand-strong: #7ab8ff;
    --accent: #15253a;
    --shadow: 0 16px 34px rgba(0, 0, 0, 0.35);
  }
}

body {
  font-family: var(--sans);
  background: linear-gradient(180deg, var(--bg), var(--bg));
  color: var(--text);
}

.sidebar {
  background: linear-gradient(180deg, #0c1a2f, #0a1527);
  color: #e3edff;
  border-right: 1px solid #1f3152;
  padding: 16px;
}

.sidebar-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.icon-btn {
  border: 1px solid #395377;
  background: #102342;
  color: #e3edff;
  border-radius: 8px;
  padding: 8px 10px;
  cursor: pointer;
}

.brand-kicker {
  margin: 0;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  opacity: 0.9;
}

.brand-title {
  margin: 2px 0 0;
  font-size: 1.05rem;
}

.sidebar-nav {
  display: grid;
  gap: 8px;
}

.nav-section {
  border: 1px solid #274268;
  border-radius: 10px;
  overflow: hidden;
}

.nav-section-btn {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  border: 0;
  background: #102442;
  color: #e6efff;
  padding: 10px 12px;
  cursor: pointer;
  text-align: left;
  font: inherit;
}

.nav-section-btn:hover { background: #133058; }

.nav-links {
  display: grid;
  gap: 4px;
  padding: 8px;
  background: #0c1c34;
}

.nav-link {
  display: block;
  text-decoration: none;
  color: #bcd1f3;
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 8px 9px;
  font-size: 0.92rem;
}

.nav-link:hover,
.nav-link.active {
  color: #fff;
  border-color: #3f6290;
  background: #14335a;
}

.nav-section[data-collapsed="true"] .nav-links {
  display: none;
}

.top-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.header-kicker {
  margin: 0;
  color: var(--muted);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.11em;
}

.header-title {
  margin: 4px 0 0;
  font-size: 1.2rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-field input {
  width: 360px;
  max-width: 56vw;
  border: 1px solid var(--line);
  background: var(--surface-soft);
  color: var(--text);
  border-radius: 10px;
  padding: 10px 12px;
  font: inherit;
}

.lang-switch {
  display: flex;
  gap: 6px;
}

.lang-btn {
  border: 1px solid var(--line);
  background: var(--surface-soft);
  color: var(--text);
  border-radius: 999px;
  padding: 8px 12px;
  cursor: pointer;
  font: inherit;
}

.lang-btn.active {
  border-color: var(--brand);
  background: var(--accent);
  color: var(--brand-strong);
  font-weight: 600;
}

.content-grid {
  padding: 24px;
}

.content section.doc-section {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 18px;
  margin-bottom: 18px;
}

.doc-h2 {
  margin: 0 0 8px;
  font-size: 1.35rem;
}

.doc-p {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
}

.module-card,
.function-card,
.info-block,
.diagram-block {
  margin-top: 14px;
  border: 1px solid var(--line);
  background: var(--surface-soft);
  border-radius: 12px;
  padding: 14px;
}

.module-title,
.function-title {
  margin: 0 0 6px;
  font-size: 1.04rem;
}

.meta-list,
.flow-list,
.rules-list {
  margin: 8px 0 0;
  padding-left: 18px;
  color: var(--muted);
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 8px;
  font-size: 0.93rem;
}

.table th,
.table td {
  border: 1px solid var(--line);
  padding: 8px;
  text-align: left;
}

.table th {
  background: var(--accent);
}

.code-tabs,
.db-tabs {
  display: flex;
  gap: 6px;
  margin-top: 10px;
}

.tab-btn {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  border-radius: 8px;
  padding: 6px 10px;
  cursor: pointer;
}

.tab-btn.active {
  border-color: var(--brand);
  color: var(--brand-strong);
  background: var(--accent);
}

.tab-panel {
  display: none;
  margin-top: 8px;
}

.tab-panel.active {
  display: block;
}

.code {
  margin: 0;
  padding: 12px;
  border-radius: 10px;
  background: #0c1a2f;
  color: #d8e8ff;
  font-family: var(--mono);
  font-size: 0.86rem;
  overflow: auto;
}

.note {
  margin-top: 10px;
  color: var(--muted);
}

.diagram-svg {
  width: 100%;
  max-width: 760px;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
}

.toc {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  box-shadow: var(--shadow);
}

.toc h3 {
  margin: 0 0 8px;
  font-size: 0.95rem;
}

.toc a {
  display: block;
  text-decoration: none;
  color: var(--muted);
  border-left: 2px solid transparent;
  padding: 6px 8px;
  margin: 2px 0;
  font-size: 0.9rem;
}

.toc a:hover,
.toc a.active {
  color: var(--brand-strong);
  border-left-color: var(--brand);
  background: var(--accent);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.hidden-by-search {
  display: none !important;
}