/* ===== Dark Mode ===== */
/* 通过 [data-theme="dark"] 选择器覆盖所有亮色样式 */

[data-theme="dark"] body,
[data-theme="dark"] {
  background: #0f172a;
  color: #e2e8f0;
}

/* ===== Navbar ===== */
[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.85);
  border-bottom-color: rgba(255, 255, 255, 0.06);
}

[data-theme="dark"] .logo-text {
  color: #f1f5f9;
}

[data-theme="dark"] .nav-link {
  color: #94a3b8;
}

[data-theme="dark"] .nav-link:hover {
  color: #f1f5f9;
}

[data-theme="dark"] .nav-link.active {
  color: #60a5fa;
}

[data-theme="dark"] .nav-search {
  color: #94a3b8;
  background: #1e293b;
}

[data-theme="dark"] .nav-search:hover {
  background: #334155;
  color: #cbd5e1;
}

[data-theme="dark"] .nav-changelog {
  color: #94a3b8;
  background: none;
}

[data-theme="dark"] .nav-changelog:hover {
  color: #cbd5e1;
}

[data-theme="dark"] .nav-github,
[data-theme="dark"] .nav-xiaohongshu {
  color: #94a3b8;
}

[data-theme="dark"] .nav-github:hover,
[data-theme="dark"] .nav-xiaohongshu:hover {
  background: #1e293b;
  color: #f1f5f9;
}

[data-theme="dark"] .nav-search-mobile {
  color: #94a3b8;
}

[data-theme="dark"] .nav-search-mobile:hover {
  background: #1e293b;
  color: #f1f5f9;
}

[data-theme="dark"] .nav-hamburger {
  color: #94a3b8;
}

[data-theme="dark"] .nav-hamburger:hover {
  background: #1e293b;
  color: #f1f5f9;
}

/* ===== Theme Toggle Button ===== */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: none;
  background: transparent;
  color: #888;
  cursor: pointer;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
  padding: 0;
}

.theme-toggle:hover {
  background: #e5e7eb;
  color: #333;
}

[data-theme="dark"] .theme-toggle {
  color: #f59e0b;
}

[data-theme="dark"] .theme-toggle:hover {
  background: #1e293b;
  color: #fbbf24;
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
  display: none;
  line-height: 0;
}

.theme-toggle .icon-moon {
  display: flex;
}

[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

[data-theme="dark"] .theme-toggle .icon-sun {
  display: flex;
}

/* ===== Mobile Navbar Theme Toggle ===== */
.nav-theme-mobile {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  cursor: pointer;
  border: none;
  background: transparent;
  color: #4a4a6a;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
  padding: 0;
}

.nav-theme-mobile:hover {
  background: #f3f4f6;
  color: #1a1a2e;
}

[data-theme="dark"] .nav-theme-mobile {
  color: #f59e0b;
}

[data-theme="dark"] .nav-theme-mobile:hover {
  background: #1e293b;
  color: #fbbf24;
}

.nav-theme-mobile .icon-sun,
.nav-theme-mobile .icon-moon {
  display: none;
  line-height: 0;
}

.nav-theme-mobile .icon-moon {
  display: flex;
}

[data-theme="dark"] .nav-theme-mobile .icon-moon {
  display: none;
}

[data-theme="dark"] .nav-theme-mobile .icon-sun {
  display: flex;
}

@media (max-width: 900px) {
  .nav-theme-mobile {
    display: flex !important;
    margin-left: auto;
    margin-right: 0;
  }

  .nav-search-mobile {
    margin-left: 0;
  }
}

/* Mobile menu theme toggle */
.mobile-theme-toggle {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 14px;
  margin: 8px 16px 0;
  background: #fff;
  border: 1.5px solid #e8edf5;
  border-radius: 12px;
  cursor: pointer;
  color: #475569;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
  font-family: inherit;
}

[data-theme="dark"] .mobile-theme-toggle {
  background: #1e293b;
  border-color: #334155;
  color: #e2e8f0;
}

.mobile-theme-toggle .mobile-theme-label-dark,
[data-theme="dark"] .mobile-theme-toggle .mobile-theme-label-light {
  display: none;
}

.mobile-theme-toggle .mobile-theme-icon-sun,
[data-theme="dark"] .mobile-theme-toggle .mobile-theme-icon-moon {
  display: none;
}

[data-theme="dark"] .mobile-theme-toggle .mobile-theme-icon-sun,
.mobile-theme-toggle .mobile-theme-icon-moon {
  display: inline;
}

[data-theme="dark"] .mobile-theme-toggle .mobile-theme-label-dark,
.mobile-theme-toggle .mobile-theme-label-light {
  display: inline;
}

/* ===== Hero Section ===== */
[data-theme="dark"] .hero {
  background:
    radial-gradient(ellipse 70% 50% at 50% 0%, rgba(99, 102, 241, 0.06) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 100%, rgba(59, 130, 246, 0.04) 0%, transparent 60%),
    radial-gradient(ellipse 40% 40% at 10% 80%, rgba(249, 115, 22, 0.03) 0%, transparent 50%),
    #0f172a;
}

[data-theme="dark"] .hero::before {
  background-image:
    linear-gradient(rgba(99, 102, 241, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 102, 241, 0.04) 1px, transparent 1px);
}

[data-theme="dark"] .hero-title {
  color: #f1f5f9;
}

[data-theme="dark"] .hero-desc,
[data-theme="dark"] .hero-subtitle {
  color: #94a3b8;
}

[data-theme="dark"] .hero-stat-dot {
  background: #334155;
}

[data-theme="dark"] .float-tag {
  background: rgba(30, 41, 59, 0.75);
  border-color: rgba(51, 65, 85, 0.8);
  color: #94a3b8;
}

[data-theme="dark"] .btn-ghost {
  background: rgba(30, 41, 59, 0.7);
  border-color: #334155;
  color: #cbd5e1;
}

[data-theme="dark"] .btn-ghost:hover {
  background: #1e293b;
  border-color: #475569;
  color: #f1f5f9;
}

[data-theme="dark"] .hero-tag {
  background: rgba(99, 102, 241, 0.10);
  border-color: rgba(99, 102, 241, 0.20);
}

/* ===== Hero Stats ===== */
[data-theme="dark"] .hero-stats {
  background: #1e293b;
  border-color: rgba(255, 255, 255, 0.06);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2), 0 8px 32px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .hero-stat-divider {
  background: #334155;
}

/* ===== Explore Section ===== */
[data-theme="dark"] .explore-section {
  background: #1e293b;
}

[data-theme="dark"] .explore-title {
  color: #f1f5f9;
}

[data-theme="dark"] .explore-desc {
  color: #94a3b8;
}

[data-theme="dark"] .explore-card {
  background: #0f172a;
  border-color: #334155;
}

[data-theme="dark"] .explore-card:hover {
  border-color: #475569;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .explore-card-coming:hover {
  border-color: #334155;
}

[data-theme="dark"] .explore-card-title {
  color: #f1f5f9;
}

[data-theme="dark"] .explore-card-desc {
  color: #94a3b8;
}

[data-theme="dark"] .explore-mini-tag {
  background: color-mix(in srgb, var(--tag-color, #64748b) 12%, #1e293b) !important;
}

/* ===== Home Sections ===== */
[data-theme="dark"] .home-section-title {
  color: #f1f5f9;
}

[data-theme="dark"] .home-section-desc {
  color: #94a3b8;
}

[data-theme="dark"] .home-contribute-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .home-contribute-card:hover {
  border-color: #475569;
}

[data-theme="dark"] .home-contribute-title {
  color: #f1f5f9;
}

[data-theme="dark"] .home-contribute-desc {
  color: #94a3b8;
}

[data-theme="dark"] .home-contribute-link {
  border-top-color: #334155;
}

[data-theme="dark"] .home-changelog-scroll::-webkit-scrollbar-thumb {
  background: #475569;
}

[data-theme="dark"] .home-changelog-entry {
  color: #94a3b8;
}

/* ===== Footer ===== */
[data-theme="dark"] .footer {
  background: #0f172a;
  border-top-color: #1e293b;
}

[data-theme="dark"] .footer-brand {
  color: #f1f5f9;
}

[data-theme="dark"] .footer-brand-icon {
  background: #f1f5f9;
}

[data-theme="dark"] .footer-brand-icon svg {
  stroke: #0f172a;
}

[data-theme="dark"] .footer-nav a {
  color: #94a3b8;
}

[data-theme="dark"] .footer-nav a:hover {
  color: #60a5fa;
}

[data-theme="dark"] .footer-social a {
  color: #94a3b8;
}

[data-theme="dark"] .footer-social a:hover {
  background: #1e293b;
  color: #cbd5e1;
}

[data-theme="dark"] .footer-divider {
  background: #1e293b;
}

[data-theme="dark"] .footer-copy {
  color: #475569;
}

/* ===== Back to Top ===== */
[data-theme="dark"] .back-to-top {
  background: rgba(30, 41, 59, 0.9);
  border-color: rgba(255, 255, 255, 0.08);
  color: #94a3b8;
}

[data-theme="dark"] .back-to-top:hover {
  background: rgba(30, 41, 59, 1);
  border-color: #60a5fa;
  color: #60a5fa;
}

/* ===== Search Modal ===== */
[data-theme="dark"] .search-overlay {
  background: rgba(0, 0, 0, 0.6);
}

[data-theme="dark"] .search-modal {
  background: #1e293b;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .search-input-wrap {
  border-bottom-color: #334155;
}

[data-theme="dark"] .search-input {
  color: #f1f5f9;
}

[data-theme="dark"] .search-kbd {
  background: #334155;
  border-color: #475569;
  color: #94a3b8;
}

[data-theme="dark"] .search-result-item:hover {
  background: #0f172a;
}

[data-theme="dark"] .search-result-title {
  color: #f1f5f9;
}

[data-theme="dark"] .search-result-desc {
  color: #94a3b8;
}

[data-theme="dark"] .search-result-tag {
  background: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .search-highlight {
  background: #854d0e;
  color: #fef08a;
}

/* ===== Loading Skeleton ===== */
[data-theme="dark"] .skeleton-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .skeleton-line,
[data-theme="dark"] .skeleton-avatar,
[data-theme="dark"] .skeleton-title {
  background: linear-gradient(90deg, #334155 25%, #475569 50%, #334155 75%);
  background-size: 200% 100%;
}

/* ===== Mobile Menu ===== */
[data-theme="dark"] .mobile-menu {
  background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
  box-shadow: -8px 0 40px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .mobile-menu-brand {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  border-bottom-color: rgba(59, 130, 246, 0.08);
}

[data-theme="dark"] .mobile-menu-brand-name {
  color: #f1f5f9;
}

[data-theme="dark"] .mobile-menu-close {
  background: rgba(51, 65, 85, 0.6);
  color: #94a3b8;
}

[data-theme="dark"] .mobile-search-btn {
  background: #0f172a;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .mobile-menu-links .mobile-link {
  color: #94a3b8;
}

[data-theme="dark"] .mobile-menu-links .mobile-link:active {
  background: #334155;
  color: #f1f5f9;
}

[data-theme="dark"] .mobile-menu-links .mobile-link.active {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.15), rgba(139, 92, 246, 0.15));
  color: #60a5fa;
}

[data-theme="dark"] .mobile-social-card {
  background: #0f172a;
  border-color: #334155;
  color: #94a3b8;
}

/* ===== Pages: Hero Sections ===== */
[data-theme="dark"] .about-hero {
  background: #0f172a;
}

[data-theme="dark"] .about-hero-title {
  color: #f1f5f9;
}

[data-theme="dark"] .about-hero-desc {
  color: #94a3b8;
}

/* ===== Pages: Main Content Areas ===== */
[data-theme="dark"] .papers-main,
[data-theme="dark"] .tools-main,
[data-theme="dark"] .articles-main,
[data-theme="dark"] .about-main {
  background: #0f172a;
}

/* ===== Sidebar ===== */
[data-theme="dark"] .papers-sidebar,
[data-theme="dark"] .tools-sidebar,
[data-theme="dark"] .articles-sidebar,
[data-theme="dark"] .about-sidebar {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .sidebar-title {
  color: #f1f5f9;
  border-bottom-color: #334155;
}

[data-theme="dark"] .sidebar-expand-all {
  background: #1e293b;
  border-color: #334155;
  color: #64748b;
}

[data-theme="dark"] .sidebar-expand-all:hover {
  background: rgba(59, 130, 246, 0.15);
  border-color: #475569;
  color: #60a5fa;
}

[data-theme="dark"] .sidebar-expand-all.active {
  background: rgba(59, 130, 246, 0.15);
  border-color: rgba(59, 130, 246, 0.3);
  color: #60a5fa;
}

[data-theme="dark"] .sidebar-link {
  color: #94a3b8;
}

[data-theme="dark"] .sidebar-link:hover {
  background: #1e293b;
  color: #f1f5f9;
}

[data-theme="dark"] .sidebar-link.active {
  color: #60a5fa;
}

/* Sidebar Level 3 Sub-items */
[data-theme="dark"] .sidebar-sub-link {
  color: #64748b;
}

[data-theme="dark"] .sidebar-sub-link:hover {
  color: #cbd5e1;
  background: rgba(255,255,255,0.03);
}

[data-theme="dark"] .sidebar-sub-link.active {
  color: #60a5fa;
  background: rgba(59,130,246,0.08);
  border-left-color: #60a5fa;
}

/* Mobile TOC Level 3 Sub-items */
[data-theme="dark"] .mobile-toc-sub-link {
  color: #64748b;
}

[data-theme="dark"] .mobile-toc-sub-link.active {
  color: #60a5fa;
  background: rgba(59, 130, 246, 0.1);
}

/* ===== Section Headers ===== */
[data-theme="dark"] .section-header {
  border-bottom-color: #334155;
}

[data-theme="dark"] .ci-op-header {
  background: #0f172a;
}

[data-theme="dark"] .section-title {
  color: #f1f5f9;
}

[data-theme="dark"] .category-header {
  background: #0f172a;
  border-bottom-color: #334155;
}

[data-theme="dark"] .category-title {
  color: #f1f5f9;
}

/* ===== Paper Cards ===== */
[data-theme="dark"] .paper-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .paper-card:hover {
  border-color: #475569;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .paper-title {
  color: #f1f5f9;
}

[data-theme="dark"] .paper-authors {
  color: #94a3b8;
}

[data-theme="dark"] .paper-abstract {
  color: #94a3b8;
}

/* Paper tag dark variants */
[data-theme="dark"] .paper-tag.blue { background: rgba(37, 99, 235, 0.15); }
[data-theme="dark"] .paper-tag.purple { background: rgba(124, 58, 237, 0.15); }
[data-theme="dark"] .paper-tag.green { background: rgba(22, 163, 74, 0.15); }
[data-theme="dark"] .paper-tag.orange { background: rgba(234, 88, 12, 0.15); }
[data-theme="dark"] .paper-tag.pink { background: rgba(219, 39, 119, 0.15); }
[data-theme="dark"] .paper-tag.cyan { background: rgba(8, 145, 178, 0.15); }
[data-theme="dark"] .paper-tag.yellow { background: rgba(180, 83, 9, 0.15); }
[data-theme="dark"] .paper-tag.indigo { background: rgba(79, 70, 229, 0.15); }
[data-theme="dark"] .paper-tag.teal { background: rgba(13, 148, 136, 0.15); }
[data-theme="dark"] .paper-tag.fuchsia { background: rgba(162, 28, 175, 0.15); }
[data-theme="dark"] .paper-tag.emerald { background: rgba(5, 150, 105, 0.15); }

/* ===== Tool Cards ===== */
[data-theme="dark"] .tool-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .tool-card:hover {
  border-color: #475569;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .tool-name {
  color: #f1f5f9;
}

[data-theme="dark"] .tool-desc {
  color: #94a3b8;
}

[data-theme="dark"] .tool-footer {
  border-top-color: #334155;
}

/* Filter buttons */
[data-theme="dark"] .filter-btn {
  color: #94a3b8;
  background: #1e293b;
}

[data-theme="dark"] .filter-btn:hover {
  background: #334155;
  color: #f1f5f9;
}

[data-theme="dark"] .filter-btn.active {
  background: #0f172a;
  color: #60a5fa;
  border-color: #60a5fa;
}

/* ===== Article Cards ===== */
[data-theme="dark"] .article-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .article-card:hover {
  border-color: #475569;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .article-name {
  color: #f1f5f9;
}

[data-theme="dark"] .article-desc {
  color: #94a3b8;
}

[data-theme="dark"] .article-footer {
  border-top-color: #334155;
}

/* Article tag dark variants */
[data-theme="dark"] .article-tag.green { background: rgba(5, 150, 105, 0.15); }
[data-theme="dark"] .article-tag.blue { background: rgba(37, 99, 235, 0.15); }
[data-theme="dark"] .article-tag.purple { background: rgba(124, 58, 237, 0.15); }
[data-theme="dark"] .article-tag.orange { background: rgba(234, 88, 12, 0.15); }
[data-theme="dark"] .article-tag.pink { background: rgba(219, 39, 119, 0.15); }
[data-theme="dark"] .article-tag.cyan { background: rgba(8, 145, 178, 0.15); }
[data-theme="dark"] .article-tag.yellow { background: rgba(180, 83, 9, 0.15); }
[data-theme="dark"] .article-tag.indigo { background: rgba(79, 70, 229, 0.15); }
[data-theme="dark"] .article-tag.teal { background: rgba(13, 148, 136, 0.15); }
[data-theme="dark"] .article-tag.red { background: rgba(220, 38, 38, 0.15); }

/* Pinned badge dark mode */
[data-theme="dark"] .article-pinned-badge {
  background: linear-gradient(135deg, #e11d48, #be123c);
  box-shadow: 0 1px 4px rgba(225, 29, 72, 0.4);
}

/* Pagination dark mode */
[data-theme="dark"] .page-btn {
  background: #1e293b;
  border-color: #334155;
  color: #94a3b8;
}
[data-theme="dark"] .page-btn:hover:not(:disabled) {
  background: #334155;
  color: #60a5fa;
  border-color: #60a5fa;
}
[data-theme="dark"] .page-dot {
  background: #475569;
}
[data-theme="dark"] .page-dot:hover {
  background: #64748b;
}
[data-theme="dark"] .page-dot.active {
  background: #3b82f6;
}
[data-theme="dark"] .page-info {
  color: #64748b;
}

/* WeChat toast */
[data-theme="dark"] .wechat-toast-inner {
  background: #1e293b;
  border-color: #334155;
}

/* ===== About Page ===== */
[data-theme="dark"] .author-card {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  border-color: #334155;
}

[data-theme="dark"] .author-name {
  color: #f1f5f9;
}

[data-theme="dark"] .author-bio p {
  color: #94a3b8;
}

[data-theme="dark"] .author-bio strong {
  color: #f1f5f9;
}

[data-theme="dark"] .site-info-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .site-info-card:hover {
  border-color: #475569;
}

[data-theme="dark"] .site-info-title {
  color: #f1f5f9;
}

[data-theme="dark"] .site-info-desc {
  color: #94a3b8;
}

[data-theme="dark"] .site-info-desc strong {
  color: #f1f5f9;
}

[data-theme="dark"] .site-stat-item {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  border-color: #334155;
}

[data-theme="dark"] .site-stat-label {
  color: #f1f5f9;
}

[data-theme="dark"] .timeline-content {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .timeline-content:hover {
  border-color: #475569;
}

[data-theme="dark"] .timeline-title {
  color: #f1f5f9;
}

[data-theme="dark"] .timeline-desc {
  color: #94a3b8;
}

[data-theme="dark"] .timeline-badge.done-badge {
  background: #064e3b;
  border-color: #065f46;
  color: #6ee7b7;
}

[data-theme="dark"] .timeline-badge.upcoming {
  background: #451a03;
  border-color: #78350f;
  color: #fdba74;
}

[data-theme="dark"] .future .timeline-content {
  border-color: #334155;
}

[data-theme="dark"] .contribute-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .contribute-card:hover {
  border-color: #475569;
}

[data-theme="dark"] .contribute-title {
  color: #f1f5f9;
}

[data-theme="dark"] .contribute-desc {
  color: #94a3b8;
}

[data-theme="dark"] .contribute-action {
  border-top-color: #334155;
}

[data-theme="dark"] .contribute-guidelines {
  background: linear-gradient(135deg, #1e293b, #0f172a);
  border-color: #334155;
}

[data-theme="dark"] .guidelines-title {
  color: #f1f5f9;
}

[data-theme="dark"] .guideline-item strong {
  color: #f1f5f9;
}

[data-theme="dark"] .guideline-item p {
  color: #94a3b8;
}

[data-theme="dark"] .contribute-intro p {
  color: #94a3b8;
}

/* ===== Flashcards Page ===== */
[data-theme="dark"] .fc-sidebar {
  background: #1e293b;
  border-right-color: #334155;
}

[data-theme="dark"] .fc-sidebar-title {
  color: #f1f5f9;
}

[data-theme="dark"] .fc-topic-btn:hover {
  background: #334155;
}

[data-theme="dark"] .fc-topic-btn.active {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(139, 92, 246, 0.15));
  border-color: rgba(99, 102, 241, 0.3);
}

[data-theme="dark"] .fc-topic-name {
  color: #e2e8f0;
}

[data-theme="dark"] .fc-sidebar-item:hover {
  background: #334155;
  color: #f1f5f9;
}

[data-theme="dark"] .fc-sidebar-count {
  background: #334155;
}

[data-theme="dark"] .fc-sidebar-divider {
  background: #334155;
}

[data-theme="dark"] .fc-hero-title {
  color: #f1f5f9;
}

[data-theme="dark"] .fc-hero-subtitle {
  color: #94a3b8;
}

[data-theme="dark"] .fc-filter-btn,
[data-theme="dark"] .fc-shuffle-btn {
  background: #1e293b;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .fc-filter-btn:hover,
[data-theme="dark"] .fc-shuffle-btn:hover {
  background: #334155;
  color: #f1f5f9;
}

[data-theme="dark"] .fc-filter-panel {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .fc-filter-tag {
  background: #0f172a;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .fc-filter-tag:hover {
  border-color: #475569;
  color: #cbd5e1;
}

[data-theme="dark"] .fc-card-back {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .fc-card-back-header {
  border-bottom-color: #334155;
}

[data-theme="dark"] .fc-card-answer {
  color: #cbd5e1;
}

[data-theme="dark"] .fc-card-answer strong {
  color: #f1f5f9;
}

[data-theme="dark"] .fc-card-answer code {
  background: #334155;
  color: #a5b4fc;
}

[data-theme="dark"] .fc-card-answer pre {
  background: #0f172a;
  border-color: #334155;
}

[data-theme="dark"] .fc-card-answer pre code {
  color: #cbd5e1;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table {
  border-color: #475569;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table th,
[data-theme="dark"] .fc-card-answer table.fc-md-table td {
  border-color: #334155;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table thead th {
  background: #1e293b;
  color: #e2e8f0;
  border-bottom-color: #475569;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table tbody td {
  background: #0f172a;
  color: #cbd5e1;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table tbody tr:nth-child(even) td {
  background: #1e293b;
}

[data-theme="dark"] .fc-card-answer table.fc-md-table tbody td:first-child {
  color: #e2e8f0;
}

[data-theme="dark"] .fc-card-refs {
  border-top-color: #334155;
}

[data-theme="dark"] .fc-ref-link {
  color: #94a3b8;
}

[data-theme="dark"] .fc-ref-link:hover {
  background: #334155;
  color: #a5b4fc;
}

[data-theme="dark"] .fc-card-tags {
  border-top-color: #334155;
}

[data-theme="dark"] .fc-tag {
  background: rgba(99, 102, 241, 0.15);
}

[data-theme="dark"] .fc-nav-btn {
  background: #1e293b;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .fc-nav-btn:hover:not(:disabled) {
  background: #334155;
}

[data-theme="dark"] .fc-dot {
  background: #334155;
}

[data-theme="dark"] .fc-dot:hover {
  background: #475569;
}

[data-theme="dark"] .fc-grid-title {
  color: #f1f5f9;
}

[data-theme="dark"] .fc-grid-card {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .fc-grid-card:hover {
  border-color: #475569;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .fc-grid-card-q {
  color: #f1f5f9;
}

[data-theme="dark"] .fc-grid-card-cat {
  background: rgba(99, 102, 241, 0.15);
}

[data-theme="dark"] .fc-grid-tag {
  background: #0f172a;
  border-color: #334155;
}

[data-theme="dark"] .fc-page-btn {
  background: #1e293b;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .fc-page-btn:hover:not(:disabled):not(.active) {
  background: #334155;
}

[data-theme="dark"] .fc-keyboard-hint {
  color: #475569;
}

[data-theme="dark"] .fc-keyboard-hint kbd {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .fc-mobile-topic-tab {
  background: #1e293b;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .fc-mobile-topic-tab:not(.active):hover {
  border-color: #6366f1;
  color: #a5b4fc;
}

/* ===== AI Assistant ===== */
[data-theme="dark"] .ai-fab {
  background: rgba(30, 41, 59, 0.92);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.04);
}

[data-theme="dark"] .ai-fab:hover {
  background: #1e293b;
}

[data-theme="dark"] .ai-fab.active {
  background: #1e293b;
}

[data-theme="dark"] .ai-panel {
  background: #1e293b;
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.04);
}

[data-theme="dark"] .ai-msg-bot-bubble {
  background: #0f172a;
  color: #e2e8f0;
}

[data-theme="dark"] .ai-quick-btn {
  background: #0f172a;
  border-color: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .ai-rec-card {
  background: #0f172a;
  border-color: #334155;
  color: #e2e8f0;
}

[data-theme="dark"] .ai-card-desc {
  color: #94a3b8;
}

[data-theme="dark"] .ai-input-area {
  border-top-color: #334155;
  background: #0f172a;
}

[data-theme="dark"] .ai-input {
  background: #1e293b;
  border-color: #334155;
  color: #f1f5f9;
}

/* ===== 404 Page ===== */
[data-theme="dark"] .error-title {
  color: #f1f5f9;
}

[data-theme="dark"] .error-desc {
  color: #94a3b8;
}

[data-theme="dark"] .error-btn-outline {
  background: #1e293b;
  border-color: #334155;
  color: #60a5fa;
}

[data-theme="dark"] .error-btn-outline:hover {
  background: #334155;
  border-color: #60a5fa;
}

[data-theme="dark"] .error-shortcut {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .error-shortcut:hover {
  border-color: #475569;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .error-shortcut-name {
  color: #cbd5e1;
}

/* ===== Buttons (global) ===== */
[data-theme="dark"] .btn-outline {
  background: #1e293b;
  color: #f97316;
  border-color: #f97316;
}

[data-theme="dark"] .btn-outline:hover {
  background: rgba(249, 115, 22, 0.1);
}

/* ===== Mobile: 600px hero stats dark ===== */
@media (max-width: 600px) {
  [data-theme="dark"] .hero {
    background:
      radial-gradient(ellipse 80% 50% at 50% 0%, rgba(99, 102, 241, 0.10) 0%, transparent 60%),
      radial-gradient(ellipse 60% 40% at 80% 100%, rgba(59, 130, 246, 0.06) 0%, transparent 50%),
      radial-gradient(ellipse 50% 50% at 10% 80%, rgba(249, 115, 22, 0.04) 0%, transparent 50%),
      linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
  }

  [data-theme="dark"] .hero-stats-inline {
    background: rgba(30, 41, 59, 0.7);
    border-color: rgba(99, 102, 241, 0.12);
  }

  [data-theme="dark"] .hero-center::before {
    border-color: rgba(99, 102, 241, 0.15);
  }
}

/* ===== Scrollbar ===== */
[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: #475569;
}

[data-theme="dark"] ::-webkit-scrollbar-track {
  background: #1e293b;
}

/* ===== Mobile TOC ===== */
[data-theme="dark"] .mobile-toc-fab {
  background: rgba(30,41,59,0.92);
  border-color: #334155;
  color: #60a5fa;
}
[data-theme="dark"] .mobile-toc-panel {
  background: #1e293b;
  box-shadow: 0 -8px 40px rgba(0,0,0,0.4);
}
[data-theme="dark"] .mobile-toc-header {
  border-bottom-color: #334155;
}
[data-theme="dark"] .mobile-toc-title {
  color: #f1f5f9;
}
[data-theme="dark"] .mobile-toc-close {
  background: #334155;
  color: #94a3b8;
}
[data-theme="dark"] .mobile-toc-item {
  color: #94a3b8;
}
[data-theme="dark"] .mobile-toc-item:active {
  background: #334155;
}
[data-theme="dark"] .mobile-toc-item.active {
  background: rgba(59,130,246,0.15);
  color: #60a5fa;
}



/* ===== Stat Intuition Page ===== */
[data-theme="dark"] .si-main {
  background: #0f172a;
}

/* Sidebar */
[data-theme="dark"] .si-sidebar {
  background: #1e293b;
  border-color: #334155;
}

[data-theme="dark"] .si-sidebar-title {
  color: #f1f5f9;
  border-bottom-color: #334155;
}

[data-theme="dark"] .si-sidebar-link {
  color: #94a3b8;
}

[data-theme="dark"] .si-sidebar-link:hover {
  background: #334155;
  color: #f1f5f9;
}

[data-theme="dark"] .si-sidebar-link.active {
  background: linear-gradient(135deg, rgba(99,102,241,0.15), rgba(139,92,246,0.15));
  color: #a5b4fc;
}

[data-theme="dark"] .si-sidebar-link-sub {
  color: #64748b;
}

[data-theme="dark"] .si-sidebar-link.active .si-sidebar-link-sub {
  color: #818cf8;
}

/* Section */
[data-theme="dark"] .si-section-header {
  background: #0f172a;
  border-bottom-color: #1e293b;
}

[data-theme="dark"] .si-section-title {
  color: #f1f5f9;
}

[data-theme="dark"] .si-section-subtitle {
  color: #64748b;
}

/* Viz Card */
[data-theme="dark"] .si-viz-card {
  background: #1e293b;
  border-color: #334155;
}

/* Canvas */
[data-theme="dark"] .si-canvas-wrap {
  background: #0f172a;
  border-color: #334155;
}

/* Controls */
[data-theme="dark"] .si-control-label {
  color: #cbd5e1;
}

[data-theme="dark"] .si-control-value {
  color: #a5b4fc;
}

[data-theme="dark"] .si-btn-secondary {
  background: #334155;
  color: #cbd5e1;
}

[data-theme="dark"] .si-btn-secondary:hover {
  background: #475569;
}

/* Stats */
[data-theme="dark"] .si-stats-box {
  background: #0f172a;
  border-color: #334155;
}

[data-theme="dark"] .si-stat-value {
  color: #f1f5f9;
}

[data-theme="dark"] .si-stat-label {
  color: #94a3b8;
}

[data-theme="dark"] .si-explain {
  background: rgba(99,102,241,0.08);
  border-color: rgba(99,102,241,0.2);
  color: #cbd5e1;
}

[data-theme="dark"] .si-explain strong {
  color: #f1f5f9;
}

/* Formula block dark mode */
[data-theme="dark"] .si-formula-block {
  background: #1e293b;
  border-color: rgba(255,255,255,0.08);
}

[data-theme="dark"] .si-formula-title {
  color: #f1f5f9;
}

[data-theme="dark"] .si-formula-row {
  background: rgba(15,23,42,0.6);
  border-color: rgba(255,255,255,0.08);
}

[data-theme="dark"] .si-formula-note {
  color: #94a3b8;
}

[data-theme="dark"] .si-formula-note code {
  background: rgba(99,102,241,0.12);
  color: #c7d2fe;
}

/* Reference block dark mode */
[data-theme="dark"] .si-ref-block {
  background: rgba(245,158,11,0.06);
  border-color: rgba(245,158,11,0.2);
}

[data-theme="dark"] .si-ref-title {
  color: #fbbf24;
}

[data-theme="dark"] .si-ref-list li {
  color: #d4d4d8;
}

[data-theme="dark"] .si-ref-list li::before {
  background: #fbbf24;
}

[data-theme="dark"] .si-ref-list a {
  color: #fbbf24;
  text-decoration-color: rgba(251,191,36,0.3);
}

[data-theme="dark"] .si-ref-list a:hover {
  color: #fde68a;
  text-decoration-color: #fde68a;
}

/* Mobile TOC */
[data-theme="dark"] .si-mobile-toc-fab {
  background: rgba(30,41,59,0.92);
  border-color: #334155;
}

[data-theme="dark"] .si-mobile-toc-panel {
  background: #1e293b;
}

[data-theme="dark"] .si-mobile-toc-header {
  border-bottom-color: #334155;
}

[data-theme="dark"] .si-mobile-toc-title {
  color: #f1f5f9;
}

[data-theme="dark"] .si-mobile-toc-close {
  background: #334155;
  color: #94a3b8;
}

[data-theme="dark"] .si-mobile-toc-item {
  color: #94a3b8;
}

[data-theme="dark"] .si-mobile-toc-item.active {
  background: linear-gradient(135deg, rgba(99,102,241,0.15), rgba(139,92,246,0.15));
  color: #a5b4fc;
}

/* ===== Left Sidebar Dark Mode ===== */
[data-theme="dark"] .ci-left-sidebar {
  background: transparent;
  border-color: transparent;
}

/* ===== Right TOC Dark Mode ===== */
[data-theme="dark"] .ci-toc-title {
  color: #f1f5f9;
  border-bottom-color: #334155;
}

[data-theme="dark"] .ci-toc-nav {
  border-left-color: #334155;
}

[data-theme="dark"] .ci-toc-section {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-toc-section:hover {
  color: #60a5fa;
}

[data-theme="dark"] .ci-toc-section.active {
  color: #60a5fa;
  border-left-color: #60a5fa;
}

[data-theme="dark"] .ci-toc-item {
  color: #64748b;
}

[data-theme="dark"] .ci-toc-type-step {
  color: #64748b;
}

[data-theme="dark"] .ci-toc-type-formula {
  color: #64748b;
}

[data-theme="dark"] .ci-toc-type-keypoint {
  color: #64748b;
}

[data-theme="dark"] .ci-toc-type-desc,
[data-theme="dark"] .ci-toc-type-when,
[data-theme="dark"] .ci-toc-type-example,
[data-theme="dark"] .ci-toc-type-vs {
  color: #94a3b8;
}

[data-theme="dark"] .ci-toc-item:hover {
  color: #94a3b8;
}

[data-theme="dark"] .ci-toc-item.active {
  color: #60a5fa;
  border-left-color: #60a5fa;
}

[data-theme="dark"] .ci-toc-empty {
  color: #475569;
}

/* ===== Causal Inference Page ===== */
[data-theme="dark"] .ci-main {
  background: #0f172a;
}

[data-theme="dark"] .ci-operator-card {
  background: transparent;
  border-color: #1e293b;
}

[data-theme="dark"] .ci-operator-card:hover {
  border-color: #1e293b;
  box-shadow: none;
}

[data-theme="dark"] .ci-op-name {
  color: #f1f5f9;
}

[data-theme="dark"] .ci-op-name-en {
  color: #64748b;
}

[data-theme="dark"] .ci-op-desc {
  color: #94a3b8;
}

[data-theme="dark"] .ci-op-when {
  background: rgba(99, 102, 241, 0.08);
  border-color: rgba(99, 102, 241, 0.2);
  color: #cbd5e1;
}

[data-theme="dark"] .ci-op-when strong {
  color: #f1f5f9;
}

[data-theme="dark"] .ci-op-desc {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-section-text {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-body-text {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-section-heading {
  color: #e2e8f0;
  border-bottom-color: #1e293b;
}

[data-theme="dark"] .ci-sh-icon {
  color: #818cf8;
}

[data-theme="dark"] .ci-sh-example {
  color: #fbbf24;
}

[data-theme="dark"] .ci-sh-vs {
  color: #94a3b8;
}

[data-theme="dark"] .ci-sh-vs .ci-sh-icon {
  color: #64748b;
}

[data-theme="dark"] .ci-body-vs {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-section-text a,
[data-theme="dark"] .ci-op-desc a,
[data-theme="dark"] .ci-body-text a {
  color: #a5b4fc;
  border-bottom-color: rgba(165, 180, 252, 0.35);
}

[data-theme="dark"] .ci-ref-item {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-ref-item a {
  color: #93c5fd;
}

[data-theme="dark"] .ci-ref-item a:hover {
  color: #bfdbfe;
}

/* Principle Section */
[data-theme="dark"] .ci-principle-text {
  color: #cbd5e1;
}

[data-theme="dark"] .ci-formula-grid {
  background: transparent;
  border-color: transparent;
}

[data-theme="dark"] .ci-formula-block {
  background: transparent;
  border-right-color: rgba(255, 255, 255, 0.08);
}

[data-theme="dark"] .ci-formula-label {
  color: #a5b4fc;
  background: rgba(165, 180, 252, 0.1);
}

[data-theme="dark"] .ci-formula-note {
  color: #cbd5e1;
  background: transparent;
  border-left-color: transparent;
}

[data-theme="dark"] .ci-note-example {
  background: rgba(99, 102, 241, 0.08);
  border-left-color: rgba(165, 180, 252, 0.25);
  color: #cbd5e1;
}

[data-theme="dark"] .ci-formula-expr .katex {
  color: #e2e8f0;
}

[data-theme="dark"] .ci-formula-expr::-webkit-scrollbar-thumb {
  background: rgba(165, 180, 252, 0.2);
}

[data-theme="dark"] .ci-formula-expr::-webkit-scrollbar-thumb:hover {
  background: rgba(165, 180, 252, 0.35);
}

[data-theme="dark"] .ci-formula-vars {
  color: #94a3b8;
  border-left-color: rgba(165, 180, 252, 0.15);
}

[data-theme="dark"] .ci-formula-vars code {
  color: #a5b4fc;
  background: rgba(165, 180, 252, 0.1);
}

[data-theme="dark"] .ci-keypoint {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.08), rgba(139, 92, 246, 0.06));
  border-color: rgba(99, 102, 241, 0.25);
  border-left-color: #818cf8;
}

[data-theme="dark"] .ci-keypoint-title {
  color: #a5b4fc;
}

[data-theme="dark"] .ci-keypoint-content {
  color: #94a3b8;
}

/* Collapsible Code */
[data-theme="dark"] .ci-code-collapse {
  border-color: rgba(165, 180, 252, 0.2);
}

[data-theme="dark"] .ci-code-summary {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(59, 130, 246, 0.08));
  color: #a5b4fc;
}

[data-theme="dark"] .ci-code-summary:hover {
  color: #c7d2fe;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(59, 130, 246, 0.12));
}

[data-theme="dark"] details.ci-code-collapse[open] .ci-code-summary {
  color: #c7d2fe;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(59, 130, 246, 0.12));
  border-bottom-color: rgba(165, 180, 252, 0.15);
}

[data-theme="dark"] .ci-code-panel {
  background: #0f172a;
}

[data-theme="dark"] .ci-code-panel pre {
  background: linear-gradient(180deg, #0f172a, #0c1322);
  color: #e2e8f0;
  border-left-color: rgba(165, 180, 252, 0.2);
}

[data-theme="dark"] .ci-code-panel code {
  color: #e2e8f0;
}

/* Python 语法高亮暗黑模式 */
[data-theme="dark"] .ci-code-panel .py-kw { color: #a5b4fc; }
[data-theme="dark"] .ci-code-panel .py-fn { color: #93c5fd; }
[data-theme="dark"] .ci-code-panel .py-str { color: #6ee7b7; }
[data-theme="dark"] .ci-code-panel .py-comment { color: #64748b; }
[data-theme="dark"] .ci-code-panel .py-num { color: #f0abfc; }
[data-theme="dark"] .ci-code-panel .py-op { color: #94a3b8; }
[data-theme="dark"] .ci-code-panel .py-builtin { color: #67e8f9; }

/* 参考文献链接状态暗黑模式 */
[data-theme="dark"] .ci-ref-item a.link-dead {
  color: #f87171;
}

[data-theme="dark"] .ci-ref-item a.link-dead::after {
  color: #f87171;
}

/* Sidebar */
[data-theme="dark"] .sidebar-module-title {
  color: #e2e8f0;
}
[data-theme="dark"] .sidebar-module-title:hover {
  color: #60a5fa;
  background: #1e293b;
}

[data-theme="dark"] .sidebar-coming {
  color: #64748b;
}

[data-theme="dark"] .sidebar-badge-soon {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
}

/* Section header background */
[data-theme="dark"] .ci-main .section-header {
  background: transparent;
}

/* Paper tags reused on CI page */
[data-theme="dark"] .ci-op-tags .paper-tag {
  color: #94a3b8;
  background: rgba(148, 163, 184, 0.1);
}

/* Mobile TOC coming items */
[data-theme="dark"] .mobile-toc-coming {
  color: #475569;
}