:root {
  --pb-font-sans: "Segoe UI", "Noto Sans TC", system-ui, sans-serif;
  --pb-font-mono: "Cascadia Code", Consolas, "Courier New", monospace;
  --pb-radius-sm: 10px;
  --pb-radius-md: 16px;
  --pb-radius-lg: 22px;
  --pb-shadow: 0 18px 42px rgba(15, 23, 42, 0.08);
  --pb-shadow-soft: 0 10px 24px rgba(15, 23, 42, 0.06);
}

html,
body {
  min-height: 100%;
}

body {
  font-family: var(--pb-font-sans);
  font-size: 14px;
  background:
    radial-gradient(circle at top left, rgba(61, 122, 183, 0.14), transparent 26rem),
    radial-gradient(circle at top right, rgba(20, 184, 166, 0.12), transparent 28rem),
    linear-gradient(180deg, var(--pb-shell) 0%, var(--pb-bg) 100%) !important;
  color: var(--pb-text);
}

body[data-bs-theme="light"] {
  --pb-bg: #eef4fb;
  --pb-shell: #f7fbff;
  --pb-panel: rgba(255, 255, 255, 0.88);
  --pb-panel-strong: #ffffff;
  --pb-panel-muted: #f3f8fd;
  --pb-text: #10243d;
  --pb-muted: #5c6f86;
  --pb-border: rgba(141, 169, 198, 0.28);
  --pb-border-strong: rgba(72, 110, 150, 0.22);
  --pb-accent: #0f6cbd;
  --pb-accent-strong: #0b5ba0;
  --pb-accent-soft: rgba(15, 108, 189, 0.12);
  --pb-code-bg: #0e1726;
  --pb-code-top: #162236;
  --pb-code-border: rgba(67, 87, 116, 0.5);
  --pb-code-text: #e8f1ff;
  --pb-code-comment: #89a7d8;
  --pb-code-keyword: #87d3ff;
  --pb-code-string: #ffc68f;
  --pb-code-number: #d8b4fe;
  --pb-mark-bg: #ffe08a;
  --pb-mark-text: #6a4a00;
  --pb-card-blur: blur(18px);
}

body[data-bs-theme="dark"] {
  --pb-bg: #07111c;
  --pb-shell: #091827;
  --pb-panel: rgba(9, 23, 37, 0.88);
  --pb-panel-strong: #0d2135;
  --pb-panel-muted: #11263b;
  --pb-text: #e5edf7;
  --pb-muted: #9db0c6;
  --pb-border: rgba(108, 133, 161, 0.24);
  --pb-border-strong: rgba(140, 170, 201, 0.2);
  --pb-accent: #63b3ff;
  --pb-accent-strong: #90caf9;
  --pb-accent-soft: rgba(99, 179, 255, 0.14);
  --pb-code-bg: #04101d;
  --pb-code-top: #0d1b2c;
  --pb-code-border: rgba(96, 121, 151, 0.42);
  --pb-code-text: #e3efff;
  --pb-code-comment: #91b4df;
  --pb-code-keyword: #7bdff6;
  --pb-code-string: #ffcf88;
  --pb-code-number: #c9b6ff;
  --pb-mark-bg: rgba(255, 216, 113, 0.95);
  --pb-mark-text: #362602;
  --pb-card-blur: blur(22px);
}

body[data-bs-theme="light"] .bg-body,
body[data-bs-theme="light"] .bg-body-tertiary,
body[data-bs-theme="light"] .card,
body[data-bs-theme="light"] .form-control,
body[data-bs-theme="light"] .form-select {
  background-color: transparent !important;
}

body[data-bs-theme="dark"] .bg-body,
body[data-bs-theme="dark"] .bg-body-tertiary,
body[data-bs-theme="dark"] .card,
body[data-bs-theme="dark"] .form-control,
body[data-bs-theme="dark"] .form-select {
  background-color: transparent !important;
}

header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: var(--pb-card-blur);
  background: color-mix(in srgb, var(--pb-shell) 78%, transparent) !important;
  border-color: var(--pb-border) !important;
}

h1,
h2,
h3,
h4 {
  letter-spacing: 0;
  color: var(--pb-text);
}

.text-body-secondary,
.status,
.topic-meta,
.result p,
.quick-list.empty,
.topic-nav-link span,
.code-label {
  color: var(--pb-muted) !important;
}

.app {
  height: calc(100vh - 84px);
  overflow-x: hidden;
}

.app > .row {
  display: grid;
  grid-template-columns: clamp(248px, 26vw, 320px) minmax(0, 1fr);
  align-items: start;
  flex-wrap: nowrap;
}

.app > .row > aside {
  min-width: 0;
  width: auto !important;
  flex: initial !important;
  max-width: 100%;
}

.app > .row > main {
  min-width: 0;
  width: auto !important;
  flex: initial !important;
  max-width: 100%;
}

.sidebar,
.topic,
.insight-pane,
.quick-panel,
.insight-card,
.result,
.book-frame,
.form-control,
.form-select,
.btn,
.contents-list,
.index-list,
.table-wrap,
.code-wrap,
.on-this-page,
.syntax-chip,
.example-preview {
  border-radius: var(--pb-radius-md) !important;
}

.sidebar.card,
.topic,
.insight-pane,
.quick-panel,
.insight-card,
.book-frame {
  border: 1px solid var(--pb-border) !important;
  background: var(--pb-panel) !important;
  box-shadow: var(--pb-shadow);
  backdrop-filter: var(--pb-card-blur);
}

.sidebar.card,
.sidebar .card-body,
.quick-panel,
.panel {
  width: 100%;
}

.sidebar .card-body > *,
.quick-panel details,
.quick-panel summary,
.quick-list,
.tabs.nav,
.field,
.status,
.contents-list,
.index-list {
  width: 100%;
}

.reader,
.sidebar {
  min-height: 0;
}

.reader {
  overflow: auto;
  overflow-x: hidden;
  display: grid;
  align-content: start;
  gap: 0.9rem;
  padding: 0.25rem 1rem 1rem 1.25rem;
}

.sidebar .card-body {
  gap: 0.25rem;
}

.hidden {
  display: none !important;
}

.panel {
  flex: 1 1 auto;
  min-height: 0;
  overflow: hidden;
}

.panel:not(.hidden) {
  display: flex;
  flex-direction: column;
}

#searchMode:not(.hidden) {
  overflow: auto;
}

.tabs.nav {
  flex-wrap: wrap;
  gap: 0.35rem;
  border: 0;
}

.tabs .nav-item {
  margin: 0;
}

.tabs .tab {
  border: 1px solid var(--pb-border);
  border-radius: 999px;
  color: var(--pb-muted);
  background: color-mix(in srgb, var(--pb-panel-strong) 76%, transparent);
  cursor: pointer;
  font-size: 0.78rem;
  padding: 0.38rem 0.78rem;
}

.tabs .tab:hover,
.tabs .tab:focus-visible {
  border-color: var(--pb-border-strong);
  background: var(--pb-panel-muted);
  color: var(--pb-text);
}

.tabs .tab.active {
  color: #fff;
  border-color: var(--pb-accent);
  background: linear-gradient(135deg, var(--pb-accent), var(--pb-accent-strong));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.14);
}

.btn {
  border-radius: 999px !important;
}

.btn-outline-secondary {
  border-color: var(--pb-border-strong) !important;
  color: var(--pb-muted) !important;
  background: color-mix(in srgb, var(--pb-panel-strong) 72%, transparent) !important;
}

.btn-outline-secondary:hover,
.btn-outline-secondary:focus-visible,
.btn-outline-secondary.active {
  color: var(--pb-text) !important;
  border-color: var(--pb-accent) !important;
  background: var(--pb-accent-soft) !important;
}

.btn-primary {
  border-color: var(--pb-accent) !important;
  background: linear-gradient(135deg, var(--pb-accent), var(--pb-accent-strong)) !important;
  box-shadow: 0 10px 22px rgba(15, 108, 189, 0.18);
}

.form-control,
.form-select {
  color: var(--pb-text) !important;
  border: 1px solid var(--pb-border) !important;
  background: color-mix(in srgb, var(--pb-panel-strong) 80%, transparent) !important;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.form-control:focus,
.form-select:focus {
  border-color: color-mix(in srgb, var(--pb-accent) 60%, white) !important;
  box-shadow: 0 0 0 0.2rem var(--pb-accent-soft) !important;
}

.quick-panel summary {
  cursor: pointer;
  list-style: none;
}

.quick-panel summary::-webkit-details-marker {
  display: none;
}

.quick-list {
  display: grid;
  gap: 0.4rem;
}

.quick-item {
  width: 100%;
  justify-content: start;
  gap: 0.55rem;
  text-align: left;
  white-space: normal;
  font-size: 0.78rem;
  border-color: var(--pb-border) !important;
}

.quick-item .badge {
  background: var(--pb-accent-soft) !important;
  color: var(--pb-accent) !important;
  border: 0 !important;
}

.contents-list,
.index-list {
  flex: 1 1 auto;
  min-height: 0;
  overflow: auto;
  border: 1px solid var(--pb-border);
  background: color-mix(in srgb, var(--pb-panel-strong) 82%, transparent);
  padding: 0.45rem;
  font-size: 0.82rem;
  line-height: 1.35;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.contents-tree {
  list-style: none;
  margin: 0;
  padding: 0 0 0 1rem;
}

.contents-tree.root {
  padding-left: 0;
}

.contents-node summary,
.contents-leaf {
  width: 100%;
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: inherit;
  text-align: left;
  padding: 0.24rem 0.4rem;
  font-size: 0.8rem;
  line-height: 1.3;
}

.contents-leaf:hover,
.contents-node summary:hover {
  background: var(--pb-accent-soft);
}

.contents-icon::before {
  display: inline-flex;
  width: 1rem;
  margin-right: 0.4rem;
  color: var(--pb-accent);
  font-size: 0.72rem;
}

.contents-icon.book::before { content: "+"; }
.contents-icon.page::before { content: "-"; }

.index-item {
  width: 100%;
  border: 0;
  border-radius: 12px;
  background: transparent;
  color: var(--pb-text);
  text-align: left;
  padding: 0.32rem 0.5rem;
  font-size: 0.8rem;
}

.index-item:hover,
.index-item:focus-visible {
  background: var(--pb-accent-soft);
}

.index-item.selected {
  background: linear-gradient(135deg, var(--pb-accent), var(--pb-accent-strong));
  color: #fff;
}

.index-item.child {
  padding-left: 1.5rem;
  color: var(--pb-muted);
}

.index-item.child::before {
  content: "- ";
  color: inherit;
}

.results,
.result-group,
.syntax-chips,
.use-grid,
.insight-section {
  display: grid;
  gap: 0.65rem;
}

.result {
  border: 1px solid var(--pb-border) !important;
  background: color-mix(in srgb, var(--pb-panel-strong) 82%, transparent) !important;
  box-shadow: var(--pb-shadow-soft);
}

.result:hover,
.result:focus-visible {
  border-color: var(--pb-accent) !important;
  background: var(--pb-panel-muted) !important;
}

.result-source {
  width: fit-content;
  background: var(--pb-accent-soft) !important;
  color: var(--pb-accent) !important;
  border-color: transparent !important;
}

.search-insight .card {
  border-color: var(--pb-border) !important;
}

.insight-pane {
  width: min(980px, 100%);
  margin: 0 auto;
  border-color: color-mix(in srgb, var(--pb-accent) 28%, var(--pb-border)) !important;
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--pb-accent-soft) 46%, transparent), transparent 13rem),
    var(--pb-panel) !important;
}

.insight-pane .card-body {
  padding: 0;
}

.insight-pane .insight-card {
  border: 0 !important;
  border-radius: inherit !important;
  background: transparent !important;
  box-shadow: none;
  backdrop-filter: none;
}

.insight-card .card-body {
  display: grid;
  gap: 0.7rem;
}

.insight-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.85rem;
  align-items: start;
}

.insight-content {
  display: grid;
  gap: 0.7rem;
}

.insight-card.collapsed .insight-content {
  display: none;
}

.insight-eyebrow {
  color: var(--pb-accent);
  font-size: 0.72rem;
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.insight-title,
.insight-section button {
  border: 0;
  background: transparent;
  color: var(--pb-text);
  text-align: left;
  padding: 0;
}

.insight-title {
  font-size: 1.05rem;
  font-weight: 700;
}

.insight-collapse {
  border: 1px solid var(--pb-border);
  border-radius: 999px;
  background: color-mix(in srgb, var(--pb-panel-strong) 78%, transparent);
  color: var(--pb-muted);
  font-size: 0.78rem;
  line-height: 1;
  padding: 0.42rem 0.68rem;
  white-space: nowrap;
}

.insight-collapse:hover,
.insight-collapse:focus-visible {
  border-color: var(--pb-accent);
  color: var(--pb-accent);
  background: var(--pb-accent-soft);
}

.insight-section-header,
.insight-category-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.75rem;
  align-items: center;
}

.insight-section-header h4,
.insight-category-header h5 {
  margin: 0;
  min-width: 0;
}

.insight-section-header span,
.insight-category-header span {
  color: var(--pb-muted);
  font-size: 0.76em;
  font-weight: 600;
}

.insight-section-toggle {
  border: 1px solid var(--pb-border);
  border-radius: 999px;
  background: color-mix(in srgb, var(--pb-panel-strong) 78%, transparent);
  color: var(--pb-muted);
  font-size: 0.74rem;
  line-height: 1;
  padding: 0.36rem 0.62rem;
  white-space: nowrap;
}

.insight-section-toggle:hover,
.insight-section-toggle:focus-visible {
  border-color: var(--pb-accent);
  color: var(--pb-accent);
  background: var(--pb-accent-soft);
}

.insight-section-content,
.insight-category-content {
  display: grid;
  gap: 0.65rem;
}

.insight-section.collapsed > .insight-section-content,
.insight-category.collapsed > .insight-category-content {
  display: none;
}

.insight-overview,
.syntax-chip span {
  color: var(--pb-muted);
}

.syntax-chip,
.example-preview {
  width: 100%;
  text-align: left;
  border: 1px solid var(--pb-border);
  background: color-mix(in srgb, var(--pb-panel-strong) 74%, transparent);
  padding: 0.75rem 0.85rem;
}

.syntax-chip strong {
  font-size: 0.9rem;
}

.search-insight,
.search-insight * {
  min-width: 0;
}

.search-insight {
  overflow: hidden;
}

.insight-card {
  overflow: hidden;
}

.insight-card .card-body {
  padding: 0.85rem !important;
}

.insight-section h4 {
  margin: 0 0 0.45rem;
  font-size: 0.98rem;
  line-height: 1.25;
}

.insight-section-header h4 {
  margin: 0;
}

.insight-section .syntax-chip {
  display: grid;
  gap: 0.18rem;
  width: 100%;
  border: 1px solid var(--pb-border);
  border-left: 3px solid var(--pb-accent);
  border-radius: 10px !important;
  background: color-mix(in srgb, var(--pb-panel-strong) 86%, transparent);
  padding: 0.52rem 0.58rem;
  line-height: 1.35;
  white-space: normal;
}

.insight-section .syntax-chip:hover,
.insight-section .syntax-chip:focus-visible {
  background: var(--pb-accent-soft);
}

.insight-section .syntax-chip strong,
.insight-section .syntax-chip span {
  display: block;
  max-width: 100%;
  white-space: normal;
  overflow-wrap: anywhere;
}

.insight-section .syntax-chip strong {
  color: var(--pb-text);
  font-size: 0.82rem;
}

.insight-section .syntax-chip span {
  color: var(--pb-muted);
  font-size: 0.78rem;
}

.insight-section + .insight-section {
  margin-top: 0.15rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--pb-border);
}

.insight-category {
  display: grid;
  gap: 0.55rem;
  border: 1px solid var(--pb-border);
  border-radius: 12px;
  background: color-mix(in srgb, var(--pb-panel-strong) 78%, transparent);
  padding: 0.65rem;
}

.insight-category h5 {
  font-size: 0.9rem;
  line-height: 1.25;
  color: var(--pb-text);
}

.insight-related-item {
  display: grid;
  gap: 0.22rem;
  width: 100%;
  border: 1px solid var(--pb-border) !important;
  border-left: 3px solid color-mix(in srgb, var(--pb-accent) 48%, var(--pb-border)) !important;
  border-radius: 10px !important;
  background: color-mix(in srgb, var(--pb-panel-strong) 88%, transparent) !important;
  padding: 0.54rem 0.6rem !important;
  text-align: left;
}

.insight-related-item.primary {
  border-left-color: var(--pb-accent) !important;
  background: var(--pb-accent-soft) !important;
}

.insight-related-item:hover,
.insight-related-item:focus-visible {
  border-color: var(--pb-accent) !important;
}

.insight-related-item strong,
.insight-related-item span {
  display: block;
  max-width: 100%;
  overflow-wrap: anywhere;
}

.insight-related-item strong {
  color: var(--pb-text);
  font-size: 0.82rem;
}

.insight-related-item span {
  color: var(--pb-muted);
  font-size: 0.78rem;
  line-height: 1.35;
}

.example-preview pre {
  margin: 0.55rem 0 0;
  max-width: 100%;
  overflow: auto;
  border-radius: 12px;
  background: var(--pb-code-bg);
}

.example-preview {
  overflow: hidden;
  display: grid;
  gap: 0;
  padding: 0 !important;
}

.example-preview button {
  display: block;
  width: 100%;
  border-bottom: 1px solid var(--pb-border);
  background: color-mix(in srgb, var(--pb-accent-soft) 58%, transparent);
  padding: 0.62rem 0.72rem;
  font-weight: 700;
  line-height: 1.35;
}

.example-preview p {
  margin: 0;
  padding: 0.62rem 0.72rem;
  font-size: 0.82rem;
  line-height: 1.48;
}

.example-preview pre {
  margin: 0 0.62rem 0.62rem;
}

.use-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.25rem;
  border: 1px solid var(--pb-border);
  border-radius: 10px;
  background: color-mix(in srgb, var(--pb-panel-strong) 78%, transparent);
  padding: 0.5rem 0.58rem;
}

.use-row + .use-row {
  margin-top: 0.4rem;
}

.use-row strong {
  color: var(--pb-accent);
  font-size: 0.78rem;
}

.use-row span,
.use-row strong,
.syntax-chip strong,
.syntax-chip span,
.example-preview button,
.example-preview p,
.result strong,
.result p,
.insight-title,
.insight-overview {
  overflow-wrap: anywhere;
}

.event-flow {
  border-top: 1px solid var(--pb-border);
  padding-top: 0.6rem;
}

.topic {
  color: var(--pb-text);
  width: min(980px, 100%);
  margin: 0 auto 1rem;
  padding: 1.05rem 1.15rem;
}

.topic .card-body {
  padding: 0;
}

.topic-title {
  font-size: clamp(1.45rem, 1.9vw, 1.8rem);
  line-height: 1.15;
  margin-bottom: 0.4rem;
  font-weight: 760;
}

.topic-meta {
  font-size: 0.82rem;
  margin-bottom: 0.8rem;
}

.topic-meta code {
  font-size: 0.78rem;
  color: var(--pb-accent);
  background: var(--pb-accent-soft);
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.12rem 0.5rem;
}

.topic-section {
  margin-top: 0.85rem;
  border: 1px solid var(--pb-border);
  border-radius: 12px;
  background: color-mix(in srgb, var(--pb-panel-strong) 54%, transparent);
  overflow: hidden;
}

.topic-section-header {
  display: grid;
  gap: 0.22rem;
  padding: 0.68rem 0.82rem;
  border-bottom: 1px solid var(--pb-border);
  background: color-mix(in srgb, var(--pb-panel-muted) 82%, transparent);
}

.topic-section-label {
  color: var(--pb-accent);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.topic-section-header h3 {
  margin: 0;
  border: 0;
  padding: 0;
  color: var(--pb-text);
  font-size: 1.02rem;
  line-height: 1.25;
}

.topic-section-body {
  padding: 0.82rem;
}

.topic-section-body > :first-child {
  margin-top: 0;
}

.topic-section-body > :last-child {
  margin-bottom: 0;
}

.topic-section-syntax .topic-section-header,
.topic-section-examples .topic-section-header {
  background: color-mix(in srgb, var(--pb-accent-soft) 64%, var(--pb-panel-muted));
}

.topic-section-syntax .code-wrap,
.topic-section-examples .code-wrap {
  margin-top: 0;
}

.topic-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem;
  margin-bottom: 0.7rem;
}

.topic-nav.bottom {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--pb-border);
}

.topic-nav-link {
  min-height: 100%;
}

.topic-nav-link.next {
  text-align: right;
}

.topic-nav-link span {
  display: block;
  font-size: 0.68rem;
  text-transform: uppercase;
}

.on-this-page {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.65rem;
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--pb-border);
  margin-bottom: 0.8rem;
  font-size: 0.78rem;
  background: color-mix(in srgb, var(--pb-panel-muted) 88%, transparent);
}

.topic h3 {
  margin-top: 1.05rem;
  margin-bottom: 0.45rem;
  padding-bottom: 0.34rem;
  border-bottom: 1px solid var(--pb-border);
  font-size: 1rem;
  line-height: 1.3;
}

.topic-heading-examples {
  color: var(--pb-accent);
  border-bottom-style: dashed;
}

.topic p,
.topic li {
  line-height: 1.62;
  font-size: 0.9rem;
}

.topic ul {
  padding-left: 1.2rem;
}

.table-wrap {
  overflow: auto;
  border: 1px solid var(--pb-border);
  margin: 0.55rem 0 0.85rem;
  background: color-mix(in srgb, var(--pb-panel-strong) 86%, transparent);
}

.table {
  margin-bottom: 0;
  color: var(--pb-text);
}

.table > :not(caption) > * > * {
  padding: 0.72rem 0.82rem;
  border-bottom-color: var(--pb-border);
  background: transparent;
}

.table tbody tr:first-child th {
  background: color-mix(in srgb, var(--pb-panel-muted) 92%, transparent);
  color: var(--pb-text);
}

.code-wrap {
  border: 1px solid var(--pb-code-border);
  overflow: hidden;
  margin: 0.55rem 0 0.9rem;
  background: var(--pb-code-bg);
  box-shadow: var(--pb-shadow-soft);
}

.code-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid var(--pb-code-border);
  background: var(--pb-code-top);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.72rem;
}

.copy-code {
  border-color: rgba(255, 255, 255, 0.16) !important;
  color: var(--pb-code-text) !important;
  background: rgba(255, 255, 255, 0.04) !important;
}

.copy-code:hover,
.copy-code:focus-visible {
  background: rgba(255, 255, 255, 0.12) !important;
}

.code-wrap pre {
  margin: 0;
  padding: 0.9rem 0.95rem 1rem;
  max-height: 360px;
  overflow: auto;
  background: var(--pb-code-bg);
}

.code-wrap code,
.example-preview code {
  font-family: var(--pb-font-mono);
  color: var(--pb-code-text);
  white-space: pre;
  font-size: 0.82rem;
  line-height: 1.6;
}

.tok-keyword { color: var(--pb-code-keyword); font-weight: 700; }
.tok-comment { color: var(--pb-code-comment); font-style: italic; }
.tok-string { color: var(--pb-code-string); }
.tok-number { color: var(--pb-code-number); }

.search-mark {
  border-radius: 5px;
  background: var(--pb-mark-bg);
  color: var(--pb-mark-text);
  padding: 0 3px;
}

.book-frame {
  width: min(980px, 100%);
  height: calc(100vh - 145px);
  margin: 0 auto 1rem;
  background: #fff;
}

.book-frame.hidden {
  display: none;
}

.topic .topic-jump,
.on-this-page a,
.insight-title,
.example-preview button {
  color: var(--pb-accent);
  text-decoration: none;
}

.topic .topic-jump:hover,
.on-this-page a:hover,
.insight-title:hover,
.example-preview button:hover {
  color: var(--pb-accent-strong);
}

figure {
  margin: 0.8rem 0 1rem;
}

img {
  max-width: 100%;
  border-radius: 12px;
  border: 1px solid var(--pb-border);
}

figcaption {
  margin-top: 0.35rem;
  font-size: 0.78rem;
  color: var(--pb-muted);
}

@media (max-width: 959.98px) {
  .app {
    height: auto;
  }

  .app > .row {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
  }

  .reader {
    padding: 0.25rem 0.35rem 0.75rem;
  }

  .topic,
  .book-frame {
    width: 100%;
  }
}

@media (max-width: 639.98px) {
  header .container-fluid,
  .app {
    padding-left: 0.55rem !important;
    padding-right: 0.55rem !important;
  }

  .sidebar .card-body,
  .topic {
    padding: 0.85rem !important;
  }

  .tabs.nav {
    gap: 0.28rem;
  }

  .tabs .tab,
  .btn,
  .quick-item {
    font-size: 0.74rem;
  }

  .quick-item {
    min-height: 2.25rem;
  }

  .search-insight,
  .results,
  .result-group,
  .insight-card .card-body,
  .insight-section,
  .syntax-chips,
  .use-grid {
    gap: 0.5rem;
  }

  .insight-card .card-body,
  .result.card.card-body,
  .example-preview,
  .syntax-chip {
    padding: 0.72rem !important;
  }

  .insight-title {
    font-size: 0.96rem;
    line-height: 1.28;
  }

  .insight-section h4 {
    font-size: 0.9rem;
  }

  .insight-overview,
  .syntax-chip span,
  .example-preview p,
  .result p,
  .use-row,
  .note-list li {
    font-size: 0.82rem;
    line-height: 1.45;
  }

  .syntax-chip strong,
  .result strong,
  .example-preview button {
    font-size: 0.86rem;
    line-height: 1.35;
  }

  .use-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.18rem;
  }

  .result-source {
    font-size: 0.68rem;
  }

  .example-preview pre {
    margin-top: 0.45rem;
  }
}

@media (max-width: 420px) {
  .insight-eyebrow {
    font-size: 0.68rem;
  }

  .insight-title {
    font-size: 0.9rem;
  }

  .insight-section h4 {
    font-size: 0.84rem;
  }

  .insight-card .card-body,
  .result.card.card-body,
  .example-preview,
  .syntax-chip {
    padding: 0.64rem !important;
  }
}