/* ===== Causal Inference Page Styles ===== */

/* --- Nav link active state --- */
.nav-link.active {
  color: #3b82f6;
  font-weight: 600;
}

/* --- Main Layout: Three-column --- */
.ci-main {
  padding: 0 0 80px;
  background: #f8fafc;
}

.ci-main-inner.ci-three-col {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 230px 1fr 200px;
  gap: 24px;
  align-items: flex-start;
  position: relative;
}

/* ===== Left Sidebar ===== */
.ci-left-sidebar {
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  background: transparent;
  border: none;
  padding: 8px 0;
}

.ci-left-sidebar::-webkit-scrollbar {
  width: 4px;
}

.ci-left-sidebar::-webkit-scrollbar-track {
  background: transparent;
}

.ci-left-sidebar::-webkit-scrollbar-thumb {
  background: #e2e8f0;
  border-radius: 4px;
}

.ci-left-sidebar::-webkit-scrollbar-thumb:hover {
  background: #cbd5e1;
}

/* Right TOC scrollbar */
.ci-right-toc::-webkit-scrollbar {
  width: 3px;
}

.ci-right-toc::-webkit-scrollbar-track {
  background: transparent;
}

.ci-right-toc::-webkit-scrollbar-thumb {
  background: #e2e8f0;
  border-radius: 3px;
}

/* --- Content Area --- */
.ci-content {
  flex: 1;
  min-width: 0;
}

/* --- Left Sidebar Navigation --- */
.sidebar-title {
  display: none;
}

.sidebar-expand-all {
  display: none;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 0;
  padding: 6px 8px 6px 12px;
  border-radius: 6px;
  border-left: none;
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  color: #475569;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  transition: all 0.15s;
  cursor: pointer;
  margin: 1px 4px;
}

.sidebar-link:hover {
  background: #f1f5f9;
  color: #1e293b;
}

.sidebar-link.active {
  color: #2563eb;
  font-weight: 600;
}

.sidebar-dot {
  display: none;
}

.sidebar-count {
  display: none;
}

.sidebar-chevron {
  display: none;
}

/* --- Sidebar Level 3: Operator Sub-items (always visible) --- */
.sidebar-section-group {
  position: relative;
}

.sidebar-sub-items {
  max-height: none;
  overflow: visible;
  padding-left: 12px;
}

.sidebar-sub-link {
  display: block;
  padding: 4px 8px 4px 12px;
  font-size: 12.5px;
  font-weight: 400;
  color: #94a3b8;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  text-decoration: none;
  border-left: 2px solid transparent;
  border-radius: 0 5px 5px 0;
  transition: all 0.15s;
  cursor: pointer;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin: 1px 4px;
}

.sidebar-sub-link:hover {
  color: #475569;
  background: #f8fafc;
}

.sidebar-sub-link.active {
  color: #2563eb;
  background: rgba(37,99,235,0.06);
  font-weight: 500;
  border-left-color: #2563eb;
}

/* --- Section Header --- */
.section-anchor {
  scroll-margin-top: 80px;
}

.ci-operator-card {
  scroll-margin-top: 80px;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
  padding: 16px 0 16px;
  border-bottom: 2px solid #f1f5f9;
}

.section-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
  color: #fff;
}

.section-icon svg {
  width: 22px;
  height: 22px;
}

.section-title {
  font-size: 24px;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 2px;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
}

.section-subtitle {
  font-size: 13px;
  color: #94a3b8;
}

/* --- Paper Tags (shared) --- */
.paper-tag {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 4px;
}

.paper-tag.blue {
  color: #2563eb;
  background: #eff6ff;
}

.paper-tag.purple {
  color: #7c3aed;
  background: #f5f3ff;
}

.paper-tag.green {
  color: #16a34a;
  background: #f0fdf4;
}

.paper-tag.orange {
  color: #ea580c;
  background: #fff7ed;
}

.paper-tag.pink {
  color: #db2777;
  background: #fdf2f8;
}

.paper-tag.cyan {
  color: #0891b2;
  background: #ecfeff;
}

.paper-tag.yellow {
  color: #b45309;
  background: #fffbeb;
}

.paper-tag.indigo {
  color: #4f46e5;
  background: #eef2ff;
}

.paper-tag.teal {
  color: #0d9488;
  background: #f0fdfa;
}

.paper-tag.fuchsia {
  color: #a21caf;
  background: #fdf4ff;
}

.paper-tag.emerald {
  color: #059669;
  background: #ecfdf5;
}

/* --- Sidebar Module Group (collapsible) --- */
.sidebar-module-group {
  margin-top: 4px;
}
.sidebar-module-group:first-child {
  margin-top: 0;
}

.sidebar-module-title {
  font-size: 14px;
  font-weight: 700;
  color: #1e293b;
  letter-spacing: 0;
  text-transform: none;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  padding: 10px 10px 10px 12px;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
  user-select: none;
}

.sidebar-module-title:hover {
  color: #2563eb;
  background: #f1f5f9;
}

.sidebar-module-text {
  flex: 1;
  min-width: 0;
}

.sidebar-module-chevron {
  flex-shrink: 0;
  transition: transform 0.25s ease;
  opacity: 0.5;
}

.sidebar-module-group.expanded .sidebar-module-chevron {
  transform: rotate(0deg);
}
.sidebar-module-group:not(.expanded) .sidebar-module-chevron {
  transform: rotate(-90deg);
}

.sidebar-module-children {
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.25s ease;
}

.sidebar-module-group.expanded .sidebar-module-children {
  max-height: 2000px;
  opacity: 1;
}
.sidebar-module-group:not(.expanded) .sidebar-module-children {
  max-height: 0;
  opacity: 0;
}

.sidebar-module-group:first-child .sidebar-module-title {
  padding-top: 4px;
}

.sidebar-coming {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px;
  font-size: 12px;
  color: #94a3b8;
  opacity: 0.7;
}

.sidebar-coming svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

.sidebar-badge-soon {
  margin-left: auto;
  font-size: 10px;
  font-weight: 600;
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.1);
  padding: 1px 6px;
  border-radius: 4px;
  white-space: nowrap;
}

/* ===== Right TOC (本页目录) ===== */
.ci-right-toc {
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding: 0;
}

.ci-toc-title {
  font-size: 13px;
  font-weight: 700;
  color: #0f172a;
  padding-bottom: 10px;
  margin-bottom: 8px;
  border-bottom: 1px solid #e8ecf1;
}

.ci-toc-nav {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-left: 1.5px solid #e8ecf1;
  padding-left: 0;
}

.ci-toc-section {
  display: block;
  font-size: 12.5px;
  font-weight: 600;
  color: #334155;
  padding: 5px 0 5px 14px;
  margin-left: -1.5px;
  border-left: 2px solid transparent;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
}

.ci-toc-section:hover {
  color: #2563eb;
}

.ci-toc-section.active {
  color: #2563eb;
  border-left-color: #2563eb;
  font-weight: 700;
}

.ci-toc-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 11.5px;
  font-weight: 400;
  color: #94a3b8;
  padding: 3.5px 0 3.5px 12px;
  margin-left: -1.5px;
  border-left: 2px solid transparent;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
}

.ci-toc-text {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
  min-width: 0;
}

.ci-toc-icon {
  flex-shrink: 0;
  opacity: 0.5;
}

.ci-toc-icon-emoji {
  flex-shrink: 0;
  font-size: 10px;
  line-height: 1;
}

/* Step 类型的目录项：作为子项缩进 */
.ci-toc-type-step {
  font-weight: 400;
  color: #64748b;
  padding-left: 22px;
  font-size: 11px;
}

/* 公式类型：作为子项缩进 */
.ci-toc-type-formula {
  color: #94a3b8;
  padding-left: 22px;
  font-size: 11px;
}

/* keypoint 类型：作为子项缩进 */
.ci-toc-type-keypoint {
  color: #94a3b8;
  padding-left: 22px;
  font-size: 11px;
}

/* 主标题（定义、场景、原理、举例、延展） */
.ci-toc-type-desc,
.ci-toc-type-when {
  color: #475569;
  font-size: 11.5px;
  font-weight: 500;
}

.ci-toc-type-example,
.ci-toc-type-vs {
  color: #475569;
  font-size: 11.5px;
  font-weight: 500;
}

.ci-toc-item:hover {
  color: #475569;
}

.ci-toc-item.active {
  color: #2563eb;
  border-left-color: #2563eb;
  font-weight: 500;
}

.ci-toc-empty {
  display: block;
  font-size: 11px;
  color: #cbd5e1;
  padding: 8px 12px;
  font-style: italic;
}

/* --- Mobile TOC --- */
.mobile-toc-fab {
  display: none;
  position: fixed;
  bottom: 124px;
  right: 18px;
  width: 44px;
  height: 44px;
  border-radius: 14px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(0,0,0,0.08);
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 89;
  color: #6366f1;
  transition: all 0.3s;
}
.mobile-toc-fab svg { width: 20px; height: 20px; }
.mobile-toc-fab:active { transform: scale(0.92); }

.mobile-toc-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.35);
  backdrop-filter: blur(4px);
  z-index: 299;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}
.mobile-toc-overlay.active { opacity: 1; pointer-events: auto; }

.mobile-toc-panel {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  max-height: 55vh;
  background: #fff;
  border-radius: 20px 20px 0 0;
  box-shadow: 0 -8px 40px rgba(0,0,0,0.12);
  z-index: 300;
  transform: translateY(100%);
  pointer-events: none;
  transition: transform 0.35s cubic-bezier(0.16,1,0.3,1);
  overflow: hidden;
  flex-direction: column;
}
.mobile-toc-panel.active { transform: translateY(0); pointer-events: auto; }

.mobile-toc-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px 12px;
  border-bottom: 1px solid #f1f5f9;
}
.mobile-toc-title {
  font-size: 15px;
  font-weight: 700;
  color: #0f172a;
}
.mobile-toc-close {
  width: 30px; height: 30px;
  border-radius: 8px; border: none;
  background: #f1f5f9; color: #64748b;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
}

.mobile-toc-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px 24px;
  -webkit-overflow-scrolling: touch;
}

.mobile-toc-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  color: #475569;
  text-decoration: none;
  transition: all 0.2s;
}
.mobile-toc-item:active { background: #f1f5f9; }
.mobile-toc-item.active {
  background: linear-gradient(135deg,#eff6ff,#f5f0ff);
  color: #3b82f6;
  font-weight: 600;
}
.mobile-toc-dot {
  width: 8px; height: 8px;
  border-radius: 50%; flex-shrink: 0;
}
.mobile-toc-count {
  margin-left: auto;
  font-size: 11px;
  color: #94a3b8;
}

/* --- Mobile TOC coming --- */
.mobile-toc-coming {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  font-size: 13px;
  color: #94a3b8;
  opacity: 0.7;
}

.mobile-toc-coming svg {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

/* --- Mobile TOC Level 3: Collapsible Sub-items --- */
.mobile-toc-section-group {
  position: relative;
}

.mobile-toc-chevron {
  margin-left: 4px;
  flex-shrink: 0;
  transition: transform 0.25s ease;
  opacity: 0.35;
  cursor: pointer;
  padding: 2px;
  border-radius: 4px;
}

.mobile-toc-chevron:hover,
.mobile-toc-chevron:active {
  opacity: 0.7;
}

.mobile-toc-section-group.expanded .mobile-toc-chevron {
  transform: rotate(180deg);
  opacity: 0.6;
}

.mobile-toc-sub-items {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  padding-left: 26px;
}

.mobile-toc-section-group.expanded .mobile-toc-sub-items {
  max-height: 500px;
}

.mobile-toc-sub-link {
  display: block;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 400;
  color: #94a3b8;
  text-decoration: none;
  border-radius: 8px;
  transition: all 0.2s;
}

.mobile-toc-sub-link:active {
  background: #f1f5f9;
}

.mobile-toc-sub-link.active {
  color: #3b82f6;
  background: #eff6ff;
  font-weight: 500;
}

/* --- Operator Card --- */
.ci-operator-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-bottom: 56px;
}

.ci-operator-list:last-child {
  margin-bottom: 0;
}

.ci-operator-card {
  background: transparent;
  border: none;
  border-radius: 0;
  padding: 24px 0;
  border-bottom: 1px solid #e8ecf1;
  transition: none;
}

.ci-operator-card:last-child {
  border-bottom: none;
}

.ci-operator-card:hover {
  border-color: #e8ecf1;
  box-shadow: none;
}

.ci-op-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
  flex-wrap: wrap;
  position: sticky;
  top: 64px;
  background: #f8fafc;
  z-index: 10;
  padding: 12px 0;
  margin-top: -12px;
}

.ci-op-titles {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
}

.ci-op-name {
  font-size: 19px;
  font-weight: 700;
  color: #0f172a;
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
}

.ci-op-name-en {
  font-size: 12.5px;
  color: #94a3b8;
  font-style: italic;
}

.ci-op-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.ci-op-tags .paper-tag {
  color: #64748b;
  background: #f1f5f9;
}

.ci-op-desc {
  font-size: 13.5px;
  color: #475569;
  line-height: 1.7;
  margin: 0 0 12px;
}

/* ===== Structured Body Sections ===== */
.ci-op-body {
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* 正文段落（无标签的自然段落流） */
.ci-body-text {
  font-size: 13.5px;
  color: #475569;
  line-height: 1.8;
  margin: 0 0 12px;
}

.ci-body-text:last-child {
  margin-bottom: 0;
}

/* 带标题的段落容器 */
.ci-labeled-section {
  margin: 0 0 20px;
}

.ci-labeled-section:last-child {
  margin-bottom: 0;
}

.ci-labeled-section .ci-body-text {
  margin-bottom: 0;
}

/* 段落小标题 */
.ci-section-heading {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: #334155;
  margin: 0 0 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid #f1f5f9;
  letter-spacing: 0.02em;
}

.ci-sh-icon {
  flex-shrink: 0;
  color: #6366f1;
  opacity: 0.7;
}

.ci-sh-icon-emoji {
  flex-shrink: 0;
  font-size: 13px;
  line-height: 1;
}

/* 示例标题颜色 */
.ci-sh-example {
  color: #d97706;
}

/* 延展标题颜色 */
.ci-sh-vs {
  color: #64748b;
}

.ci-sh-vs .ci-sh-icon {
  color: #94a3b8;
}

/* 延展段落的样式（与正文保持一致） */
.ci-body-vs {
  color: #475569;
  font-size: 13.5px;
}

/* 保留 ci-section-block 兼容旧结构 */
.ci-section-block {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 8px 0;
}

.ci-section-label {
  flex-shrink: 0;
  font-size: 12px;
  font-weight: 600;
  color: #6366f1;
  background: #eef2ff;
  border-radius: 4px;
  padding: 2px 8px;
  margin-top: 1px;
  line-height: 1.6;
  letter-spacing: 0.5px;
}

.ci-section-text {
  font-size: 13.5px;
  color: #475569;
  line-height: 1.75;
  margin: 0;
}

/* Inline reference links (superscript style) */
.ci-section-text a,
.ci-op-desc a,
.ci-body-text a {
  color: #6366f1;
  text-decoration: none;
  border-bottom: 1px dashed rgba(99, 102, 241, 0.35);
  padding-bottom: 0;
  transition: all 0.15s;
}

.ci-section-text a:hover,
.ci-op-desc a:hover,
.ci-body-text a:hover {
  color: #4f46e5;
  border-bottom-color: #4f46e5;
  border-bottom-style: solid;
}

.ci-section-text a::after,
.ci-op-desc a::after,
.ci-body-text a::after {
  content: none;
}

.ci-section-example {
  font-size: 13px;
  color: #64748b;
  line-height: 1.75;
  background: #fefce8;
  border-left: 3px solid #eab308;
  border-radius: 0 6px 6px 0;
  padding: 10px 14px;
}

.ci-section-example .ci-principle-text {
  margin: 0;
  font-size: inherit;
  color: inherit;
}

/* ===== Principle inside section block ===== */
.ci-section-block .ci-principle {
  flex: 1;
  min-width: 0;
}

/* ===== Unified Collapse Group ===== */
.ci-collapse-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid #f1f5f9;
}

.ci-collapse-item {
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  overflow: hidden;
}

.ci-collapse-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px;
  font-size: 12.5px;
  font-weight: 600;
  color: #475569;
  background: #f8fafc;
  cursor: pointer;
  list-style: none;
  user-select: none;
  -webkit-user-select: none;
  transition: background 0.15s;
}

.ci-collapse-summary::-webkit-details-marker {
  display: none;
}

.ci-collapse-summary::marker {
  display: none;
  content: '';
}

.ci-collapse-summary:hover {
  background: #f1f5f9;
  color: #334155;
}

.ci-collapse-label {
  display: flex;
  align-items: center;
  gap: 6px;
}

.ci-collapse-label svg {
  stroke: #64748b;
  flex-shrink: 0;
}

.ci-collapse-chevron {
  stroke: #94a3b8;
  transition: transform 0.2s;
  flex-shrink: 0;
}

.ci-collapse-item[open] .ci-collapse-chevron {
  transform: rotate(180deg);
}

.ci-collapse-item[open] .ci-collapse-summary {
  border-bottom: 1px solid #e2e8f0;
}

.ci-collapse-body {
  padding: 12px 14px;
}

.ci-collapse-body:has(> pre) {
  padding: 0;
}

/* -- Pros/Cons inside collapse -- */
.ci-proscons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 10px;
}

.ci-proscons-col {
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 12px;
  line-height: 1.7;
}

.ci-pros {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
}

.ci-cons {
  background: #fff7ed;
  border: 1px solid #fed7aa;
}

.ci-proscons-label {
  font-weight: 600;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
}

.ci-pros .ci-proscons-label {
  color: #15803d;
}

.ci-pros .ci-proscons-label svg {
  stroke: #16a34a;
}

.ci-cons .ci-proscons-label {
  color: #c2410c;
}

.ci-cons .ci-proscons-label svg {
  stroke: #ea580c;
}

.ci-proscons-col ul {
  margin: 0;
  padding-left: 16px;
}

.ci-proscons-col li {
  color: #475569;
  margin-bottom: 2px;
}

.ci-pros li::marker {
  color: #22c55e;
}

.ci-cons li::marker {
  color: #f97316;
}


@media (max-width: 640px) {
  .ci-proscons {
    grid-template-columns: 1fr;
  }
  .ci-section-block {
    flex-direction: column;
    gap: 4px;
  }
  .ci-section-label {
    align-self: flex-start;
  }
}

/* ===== Principle Section ===== */
.ci-principle {
  margin-bottom: 0;
}

.ci-principle-text {
  font-size: 13.5px;
  color: #334155;
  line-height: 1.8;
  margin: 0 0 14px;
}

/* --- Formula Grid (side-by-side) --- */
.ci-formula-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin: 8px 0;
  background: transparent;
  border: none;
  border-radius: 0;
  padding: 0;
}

.ci-formula-grid.cols-1 {
  grid-template-columns: 1fr;
}

.ci-formula-grid.cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

/* --- Formula Block --- */
.ci-formula-block {
  background: transparent;
  border: none;
  border-radius: 0;
  padding: 4px 8px;
  text-align: center;
  margin: 0;
  border-right: 1px solid #e8ecf1;
  min-width: 0;
  overflow: hidden;
}

.ci-formula-block:last-child,
.ci-formula-grid.cols-1 .ci-formula-block {
  border-right: none;
}

.ci-formula-grid .ci-formula-block {
  margin: 0;
}

.ci-formula-label {
  display: inline-block;
  font-size: 10px;
  font-weight: 600;
  color: #6366f1;
  letter-spacing: 0.3px;
  margin-bottom: 2px;
  padding: 1px 6px;
  background: rgba(99, 102, 241, 0.08);
  border-radius: 3px;
}

.ci-formula-expr {
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  padding: 4px 0;
  text-align: center;
  max-width: 100%;
}

.ci-formula-expr::-webkit-scrollbar {
  height: 4px;
}

.ci-formula-expr::-webkit-scrollbar-track {
  background: transparent;
}

.ci-formula-expr::-webkit-scrollbar-thumb {
  background: rgba(99, 102, 241, 0.2);
  border-radius: 2px;
}

.ci-formula-expr::-webkit-scrollbar-thumb:hover {
  background: rgba(99, 102, 241, 0.35);
}

.ci-formula-expr .katex-display {
  margin: 0;
  overflow-x: visible;
}

.ci-formula-expr .katex {
  font-size: 1em;
  white-space: nowrap;
}

/* --- Formula 变量说明 --- */
.ci-formula-vars {
  margin-top: 3px;
  font-size: 11px;
  color: #64748b;
  line-height: 1.5;
  text-align: left;
  padding: 2px 0 0 0;
  border-left: none;
}

.ci-formula-vars > div {
  margin-bottom: 1px;
}

.ci-formula-vars code {
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 10.5px;
  color: #6366f1;
  background: rgba(99, 102, 241, 0.06);
  padding: 0 4px;
  border-radius: 3px;
}

/* --- Formula 解读文字 (spans full width below grid) --- */
.ci-formula-note {
  grid-column: 1 / -1;
  font-size: 12.5px;
  color: #475569;
  line-height: 1.7;
  margin: 2px 0 0;
  padding: 0;
  background: transparent;
  border-radius: 0;
  border-left: none;
}

.ci-note-example {
  display: block;
  margin-top: 6px;
  padding: 6px 10px;
  background: rgba(99, 102, 241, 0.04);
  border-left: 3px solid rgba(99, 102, 241, 0.2);
  border-radius: 4px;
  color: #475569;
  font-style: normal;
}

/* --- References (inside collapse) --- */

.ci-ref-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.ci-ref-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 12.5px;
  line-height: 1.6;
  color: #475569;
}

.ci-ref-item a {
  color: #3b82f6;
  text-decoration: none;
  word-break: break-all;
}

.ci-ref-item a:hover {
  text-decoration: underline;
  color: #2563eb;
}

.ci-ref-badge {
  font-size: 10px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 3px;
  white-space: nowrap;
  flex-shrink: 0;
  margin-top: 2px;
}

.ci-ref-badge.paper {
  color: #7c3aed;
  background: #f5f3ff;
}

.ci-ref-badge.blog {
  color: #0891b2;
  background: #ecfeff;
}

/* --- Keypoint Block --- */
.ci-keypoint {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.04), rgba(139, 92, 246, 0.04));
  border: 1px solid rgba(99, 102, 241, 0.15);
  border-left: 3px solid #6366f1;
  border-radius: 8px;
  padding: 14px 16px;
  margin: 14px 0;
}

.ci-keypoint-title {
  font-size: 13px;
  font-weight: 700;
  color: #4f46e5;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 5px;
}

.ci-keypoint-title svg {
  flex-shrink: 0;
}

.ci-keypoint-content {
  font-size: 13px;
  color: #475569;
  line-height: 1.7;
  margin: 0;
}

/* ===== Python Code Panel (inside collapse) ===== */

.ci-collapse-body pre {
  margin: 0;
  padding: 16px 20px;
  background: linear-gradient(180deg, #fafaff, #fafbfc);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-left: 3px solid rgba(99, 102, 241, 0.15);
}

.ci-collapse-body code {
  font-family: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;
  font-size: 12.5px;
  line-height: 1.7;
  color: #334155;
  white-space: pre;
  tab-size: 2;
}

/* Python 关键字/注释 高亮色 */
.ci-collapse-body .py-kw { color: #6366f1; font-weight: 600; }
.ci-collapse-body .py-fn { color: #2563eb; }
.ci-collapse-body .py-str { color: #059669; }
.ci-collapse-body .py-comment { color: #94a3b8; font-style: italic; }
.ci-collapse-body .py-num { color: #d946ef; }
.ci-collapse-body .py-op { color: #64748b; }
.ci-collapse-body .py-builtin { color: #0891b2; }

/* --- Responsive --- */
/* 隐藏右栏 + 中等屏幕 */
@media (max-width: 1200px) {
  .ci-right-toc {
    display: none;
  }
  .ci-main-inner.ci-three-col {
    grid-template-columns: 230px 1fr;
  }
}

/* 隐藏左栏 + 显示移动端 TOC */
@media (max-width: 900px) {
  .ci-left-sidebar {
    display: none;
  }
  .ci-main-inner.ci-three-col {
    grid-template-columns: 1fr;
    padding: 0 16px;
  }
  .mobile-toc-fab, .mobile-toc-overlay, .mobile-toc-panel {
    display: flex;
  }
  .ci-op-header {
    flex-direction: column;
    gap: 8px;
  }

  .section-title {
    font-size: 20px;
  }
}

@media (max-width: 600px) {
  .ci-main-inner {
    padding: 0 16px;
  }

  .ci-operator-card {
    padding: 16px 0;
  }

  .ci-op-name {
    font-size: 15px;
  }

  .ci-collapse-body pre {
    padding: 12px 14px;
  }

  .ci-collapse-body code {
    font-size: 11.5px;
  }

  .section-header {
    gap: 12px;
  }

  .section-icon {
    width: 40px;
    height: 40px;
    font-size: 18px;
  }

  .section-icon svg {
    width: 18px;
    height: 18px;
  }

  .ci-formula-grid {
    grid-template-columns: 1fr;
    padding: 8px 10px;
  }

  .ci-formula-grid.cols-3 {
    grid-template-columns: 1fr;
  }

  .ci-formula-block {
    padding: 4px 0;
  }

  .ci-formula-expr .katex {
    font-size: 0.9em;
  }

  .ci-formula-vars {
    font-size: 10.5px;
  }

  .ci-formula-note {
    font-size: 11.5px;
    padding: 0;
  }

  .ci-keypoint {
    padding: 12px 14px;
  }
}