html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

/* Custom Sleek Dark Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--nv-dark-bg);
}

::-webkit-scrollbar-thumb {
  background: var(--nv-border-light);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--nv-green);
}

/* Rendering Performance Optimization */
.search-result-card,
.lesson-item-card {
  content-visibility: auto;
  contain-intrinsic-size: 1px 120px;
}

.ascii-bg {
  transform: translateZ(0);
  will-change: opacity;
}

:root {
  /* Color Tokens */
  --nv-green: #8DC31F;
  --nv-green-hover: #9ce220;
  --nv-green-glow: rgba(141, 195, 31, 0.25);
  --nv-dark-bg: #0d1012;
  --nv-surface-1: #15191c;
  --nv-surface-2: #1e2327;
  --nv-surface-3: #282f34;
  --nv-border: #2d353b;
  --nv-border-light: #3e4850;
  
  --text-primary: #f0f4f7;
  --text-secondary: #a0acb5;
  --text-muted: #677580;

  --alert-note-bg: rgba(33, 150, 243, 0.08);
  --alert-note-border: #2196f3;
  --alert-warn-bg: rgba(255, 152, 0, 0.08);
  --alert-warn-border: #ff9800;
  --alert-caution-bg: rgba(244, 67, 54, 0.08);
  --alert-caution-border: #f44336;

  --sidebar-width: 300px;
  --toc-width: 260px;
  --header-height: 64px;
  
  --font-main: 'JetBrains Mono', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-code: 'JetBrains Mono', Consolas, Monaco, monospace;
}

/* Light Theme Overrides */
[data-theme="light"] {
  --nv-dark-bg: #f8fafc;
  --nv-surface-1: #ffffff;
  --nv-surface-2: #f1f5f9;
  --nv-surface-3: #e2e8f0;
  --nv-border: #e2e8f0;
  --nv-border-light: #cbd5e1;
  
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;

  --alert-note-bg: #eff6ff;
  --alert-warn-bg: #fff7ed;
  --alert-caution-bg: #fef2f2;
}

[data-theme="light"] .dli-header {
  background-color: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid #e2e8f0;
}

[data-theme="light"] .brand-logo-img {
  content: url("../image/seeed_logo_c.svg");
}

[data-theme="light"] .hero-section {
  background: radial-gradient(circle at 50% 0%, rgba(141, 195, 31, 0.18) 0%, rgba(255, 255, 255, 0) 70%),
              linear-gradient(180deg, #ffffff 0%, #f1f5f9 100%);
  border-bottom: 1px solid #e2e8f0;
}

[data-theme="light"] .hero-title {
  background: linear-gradient(135deg, #0f172a 0%, #334155 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

[data-theme="light"] .hero-description {
  color: #475569;
}

[data-theme="light"] .hero-meta-badge {
  background-color: #ffffff;
  border-color: #cbd5e1;
  color: #334155;
}

[data-theme="light"] .chapter-card {
  background-color: #ffffff;
  border-color: #e2e8f0;
}

[data-theme="light"] .chapter-card:hover {
  border-color: var(--nv-green);
  box-shadow: 0 10px 25px -5px rgba(141, 195, 31, 0.15);
}

[data-theme="light"] .chapter-card-title {
  color: #0f172a;
}

[data-theme="light"] .chapter-card-desc {
  color: #475569;
}

[data-theme="light"] .search-trigger-btn {
  background-color: #f1f5f9;
  border-color: #cbd5e1;
  color: #334155;
}

[data-theme="light"] .search-trigger-btn:hover {
  background-color: #e2e8f0;
  border-color: var(--nv-green);
  color: #0f172a;
}

[data-theme="light"] .kbd-shortcut {
  background-color: #e2e8f0;
  border-color: #cbd5e1;
  color: #475569;
}

[data-theme="light"] .code-block-wrapper pre {
  background-color: #121619 !important;
  border-top: 1px solid #2d353b;
  color: #e2e8f0 !important;
}

[data-theme="light"] .code-block-wrapper pre code,
[data-theme="light"] .code-block-wrapper pre * {
  color: #e2e8f0;
}

[data-theme="light"] .code-header {
  background-color: #f1f5f9;
  color: #334155;
  border-bottom: 1px solid #cbd5e1;
}

[data-theme="light"] .markdown-body code:not([class*="language-"]) {
  background-color: #f1f5f9;
  color: #5d8e0e;
  border-color: #cbd5e1;
}

/* Light Theme Clean 3D Card & Spotlight System */
[data-theme="light"] .chapter-block {
  background-color: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.03);
}

[data-theme="light"] .chapter-header {
  background-color: #f8fafc;
  border-bottom-color: #e2e8f0;
}

[data-theme="light"] .lessons-list {
  background-color: #f8fafc;
}

[data-theme="light"] .lesson-item-card {
  background-color: #ffffff;
  border: 1px solid #e2e8f0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

[data-theme="light"] .lesson-item-card:hover {
  border-color: var(--nv-green);
  background-color: #ffffff;
  box-shadow: 0 12px 32px -6px rgba(141, 195, 31, 0.22), 0 4px 12px rgba(0, 0, 0, 0.05);
}

[data-theme="light"] .lesson-item-card .card-spotlight {
  background: radial-gradient(320px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(141, 195, 31, 0.14), transparent 80%);
}

[data-theme="light"] .feature-card {
  background-color: #ffffff;
  border-color: #e2e8f0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.03);
}

[data-theme="light"] .feature-card:hover {
  border-color: var(--nv-green);
  box-shadow: 0 12px 28px -4px rgba(141, 195, 31, 0.18), 0 4px 12px rgba(0, 0, 0, 0.04);
}

/* Custom Sleek Scrollbar for Sidebars & Containers */
.sidebar-nav,
.toc-nav,
.search-results-list,
.code-block-wrapper pre {
  scrollbar-width: thin;
  scrollbar-color: var(--nv-border) transparent;
}

.sidebar-nav::-webkit-scrollbar,
.toc-nav::-webkit-scrollbar,
.search-results-list::-webkit-scrollbar,
.code-block-wrapper pre::-webkit-scrollbar {
  width: 4px;
  height: 4px;
}

.sidebar-nav::-webkit-scrollbar-track,
.toc-nav::-webkit-scrollbar-track,
.search-results-list::-webkit-scrollbar-track,
.code-block-wrapper pre::-webkit-scrollbar-track {
  background: transparent;
}

.sidebar-nav::-webkit-scrollbar-thumb,
.toc-nav::-webkit-scrollbar-thumb,
.search-results-list::-webkit-scrollbar-thumb,
.code-block-wrapper pre::-webkit-scrollbar-thumb {
  background: var(--nv-border);
  border-radius: 10px;
  transition: background 0.2s ease;
}

.sidebar-nav:hover::-webkit-scrollbar-thumb,
.toc-nav:hover::-webkit-scrollbar-thumb,
.search-results-list:hover::-webkit-scrollbar-thumb {
  background: var(--nv-border-light);
}

.sidebar-nav::-webkit-scrollbar-thumb:hover,
.toc-nav::-webkit-scrollbar-thumb:hover {
  background: var(--nv-green);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

button, input, select, textarea {
  font-family: var(--font-main);
}

kbd {
  font-family: var(--font-code);
}

body {
  font-family: var(--font-main);
  background-color: var(--nv-dark-bg);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--nv-green);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--nv-green-hover);
  text-decoration: underline;
}

/* ==========================================================================
   Header Navbar
   ========================================================================== */

.dli-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: rgba(21, 25, 28, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--nv-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  z-index: 1000;
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  cursor: pointer;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.brand-logo-img {
  height: 26px;
  width: auto;
  object-fit: contain;
  display: block;
  transition: filter 0.3s ease, transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.brand-container:hover .brand-logo-img {
  filter: drop-shadow(0 0 10px rgba(118, 185, 0, 0.7));
  transform: scale(1.06);
}

.nvidia-logo-badge {
  background-color: var(--nv-green);
  color: #000;
  font-weight: 900;
  font-size: 0.85rem;
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.brand-title {
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  white-space: nowrap;
}

.brand-subtitle {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.88rem;
  transition: color 0.25s ease, transform 0.25s ease;
  white-space: nowrap;
}

.brand-container:hover .brand-subtitle {
  color: var(--nv-green);
  transform: translateX(3px);
}

@media (max-width: 1280px) {
  .brand-subtitle {
    display: none;
  }
}

@media (max-width: 1080px) {
  .brand-title {
    display: none;
  }
}

.header-center {
  flex: 1;
  max-width: 420px;
  margin: 0 1.5rem;
}

.search-trigger-btn {
  width: 360px;
  background-color: var(--nv-surface-2);
  border: 1px solid var(--nv-border);
  border-radius: 8px;
  padding: 0.45rem 0.85rem;
  color: var(--text-secondary);
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  white-space: nowrap;
  gap: 0.5rem;
  transition: all 0.2s ease;
}

.search-trigger-btn span:first-child {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.search-trigger-btn:hover {
  border-color: var(--nv-green);
  background-color: var(--nv-surface-3);
  color: var(--text-primary);
}

.kbd-shortcut {
  background-color: var(--nv-surface-3);
  border: 1px solid var(--nv-border);
  border-radius: 4px;
  padding: 0.15rem 0.4rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-code);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.icon-btn {
  background: transparent;
  border: 1px solid var(--nv-border);
  color: var(--text-secondary);
  width: 38px;
  height: 38px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  font-weight: 700;
  font-size: 0.85rem;
  line-height: 1;
}

.icon-btn:hover {
  border-color: var(--nv-green);
  color: var(--nv-green);
  background-color: var(--nv-surface-2);
}

/* ==========================================================================
   Landing Page View
   ========================================================================== */

#landing-view {
  padding-top: var(--header-height);
  min-height: 100vh;
}

.hero-section {
  position: relative;
  padding: 0;
  background: radial-gradient(circle at 80% 50%, rgba(141, 195, 31, 0.12) 0%, rgba(13, 16, 18, 0) 70%),
              linear-gradient(180deg, #121619 0%, #0d1012 100%);
  border-bottom: 1px solid var(--nv-border);
  overflow: hidden;
  min-height: 540px;
  display: flex;
  align-items: stretch;
}

canvas.ascii-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.85;
}

.hero-container {
  max-width: 1440px;
  width: 100%;
  min-height: 540px;
  margin: 0 auto;
  padding: 0 2.5rem;
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
}

.hero-bg-overlay {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  pointer-events: none;
  z-index: 1;
}

.hero-left-col {
  padding: 4.5rem 0 5rem 0;
  max-width: 820px;
  text-align: left;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  position: relative;
  z-index: 3;
}

.hero-title {
  font-size: clamp(2.6rem, 4.2vw, 3.8rem);
  font-weight: 800;
  line-height: 1.12;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
  color: #9BE531;
  font-family: 'JetBrains Mono', 'Noto Sans SC', Consolas, monospace;
}

.hero-desc {
  font-size: clamp(0.95rem, 1.2vw, 1.18rem);
  color: rgba(240, 244, 247, 0.85);
  line-height: 1.55;
  margin-bottom: 2.25rem;
  font-family: 'JetBrains Mono', 'Noto Sans SC', Consolas, monospace;
  text-align: left;
  max-width: 100%;
}

.hero-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, auto));
  gap: 1.6rem 3.5rem;
  margin-bottom: 2.5rem;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
}

.stat-val {
  font-size: 1.55rem;
  font-weight: 800;
  color: #9BE531;
  font-family: 'JetBrains Mono', 'Noto Sans SC', Consolas, monospace;
  line-height: 1.2;
}

.stat-lbl {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-top: 0.25rem;
  font-family: 'JetBrains Mono', 'Noto Sans SC', Consolas, monospace;
}

.cta-group {
  display: flex;
  justify-content: flex-start;
  gap: 1rem;
}

.btn-primary.btn-pill {
  background: linear-gradient(135deg, #a6f238 0%, #8dc31f 100%);
  color: #0b0e10;
  font-weight: 800;
  padding: 0.85rem 2.2rem;
  border-radius: 9999px;
  font-size: 1.05rem;
  border: none;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  box-shadow: 0 4px 20px rgba(141, 195, 31, 0.35);
  letter-spacing: 0.2px;
}

.btn-primary.btn-pill:hover {
  background: linear-gradient(135deg, #b5ff42 0%, #9be531 100%);
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 28px rgba(141, 195, 31, 0.5);
  text-decoration: none;
}

@media (max-width: 992px) {
  .hero-container {
    justify-content: center;
  }
  .hero-left-col {
    max-width: 100%;
    margin: 0 auto;
    padding: 3rem 1rem;
    align-items: center;
    text-align: center;
  }
  .hero-title {
    text-align: center;
  }
  .hero-desc {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
  }
  .hero-stats-grid {
    width: 100%;
    justify-content: center;
    gap: 1.5rem 2rem;
  }
  .stat-item {
    align-items: center;
    text-align: center;
  }
  .cta-group {
    width: 100%;
    justify-content: center;
  }
}

.btn-secondary {
  background-color: var(--nv-surface-2);
  color: var(--text-primary);
  border: 1px solid var(--nv-border);
  font-weight: 600;
  padding: 0.8rem 1.8rem;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.25s ease;
}

.btn-secondary:hover {
  border-color: var(--nv-border-light);
  background-color: var(--nv-surface-3);
  text-decoration: none;
}

/* Sections Layout */
.landing-body {
  max-width: 1440px;
  margin: 0 auto;
  padding: 3.5rem 2.5rem;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-title i {
  color: var(--nv-green);
}

.section-sub {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-size: 1rem;
}

/* Overview Feature Grid */
.overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-bottom: 4rem;
}

.feature-card {
  background-color: var(--nv-surface-1);
  border: 1px solid var(--nv-border);
  border-radius: 16px;
  padding: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 2;
  transform-style: preserve-3d;
  transition: transform 0.15s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.15s ease, border-color 0.3s ease;
  will-change: transform, box-shadow;
  --mouse-x: 50%;
  --mouse-y: 50%;
}

.feature-card::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1.2px;
  background: radial-gradient(
    240px circle at var(--mouse-x) var(--mouse-y),
    rgba(141, 195, 31, 0.65) 0%,
    rgba(141, 195, 31, 0.25) 45%,
    rgba(255, 255, 255, 0.06) 75%,
    transparent 100%
  );
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 12;
}

.feature-card:hover::before {
  opacity: 1;
}

.card-spotlight-glow {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  z-index: 10;
  opacity: 0;
  transition: opacity 0.35s ease;
  background: radial-gradient(
    320px circle at var(--mouse-x) var(--mouse-y),
    rgba(141, 195, 31, 0.16) 0%,
    rgba(141, 195, 31, 0.05) 40%,
    transparent 70%
  );
}

.feature-card:hover .card-spotlight-glow {
  opacity: 1;
}

.feature-media-box {
  width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
  border-radius: 0;
  overflow: hidden;
  margin-bottom: 0;
  border: none;
  border-bottom: 1px solid var(--nv-border);
  background-color: var(--nv-surface-2);
  position: relative;
}

.feature-media-box video,
.feature-media-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.4s ease;
}

.feature-card:hover .feature-media-box video,
.feature-card:hover .feature-media-box img {
  transform: scale(1.04);
}

.feature-card-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.925rem;
}

/* Workflow Pipeline Grid */
.workflow-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1rem;
}

.workflow-card {
  background-color: var(--nv-surface-1);
  border: 1px solid var(--nv-border);
  border-radius: 10px;
  overflow: hidden;
  transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
  cursor: default;
}

.workflow-card:hover {
  transform: translateY(-4px);
  border-color: var(--nv-green);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.workflow-img-box {
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background-color: var(--nv-dark-bg);
}

.workflow-img-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.35s ease;
}

.workflow-card:hover .workflow-img-box img {
  transform: scale(1.05);
}

.workflow-label {
  display: block;
  text-align: center;
  padding: 0.75rem 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  white-space: nowrap;
}

@media (max-width: 1100px) {
  .workflow-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 640px) {
  .workflow-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Chapters Modules Cards */
.chapters-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.chapter-block {
  background-color: var(--nv-surface-1);
  border: 1px solid var(--nv-border);
  border-radius: 12px;
  overflow: hidden;
}

.chapter-header {
  background-color: var(--nv-surface-2);
  padding: 1.25rem 1.75rem;
  border-bottom: 1px solid var(--nv-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chapter-title-wrap {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.chapter-badge {
  background-color: var(--nv-green);
  color: #000;
  font-weight: 800;
  font-size: 0.85rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
}

.chapter-title-text {
  font-size: 1.2rem;
  font-weight: 700;
}

.lessons-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1rem;
  padding: 1.25rem;
  background-color: var(--nv-surface-1);
}

.lesson-item-card {
  position: relative;
  overflow: hidden;
  background-color: var(--nv-surface-2);
  border: 1px solid var(--nv-border);
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
  transform-style: preserve-3d;
  perspective: 1000px;
  transition: transform 0.15s ease-out, border-color 0.25s ease, box-shadow 0.25s ease, background-color 0.2s ease;
}

.lesson-item-card > * {
  position: relative;
  z-index: 2;
}

.lesson-item-card .card-spotlight {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s ease;
  background: radial-gradient(350px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(118, 185, 0, 0.18), transparent 75%);
  z-index: 1;
}

.lesson-item-card:hover {
  background-color: var(--nv-surface-3);
  border-color: var(--nv-green);
  box-shadow: 0 10px 30px -10px rgba(118, 185, 0, 0.25), 0 0 15px rgba(118, 185, 0, 0.1);
}

.lesson-item-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;

}

.lesson-item-card:hover .lesson-item-title {
  color: var(--nv-green);
}

.lesson-id-tag {
  font-size: 0.75rem;
  font-family: var(--font-code);
  color: var(--text-muted);
  background-color: var(--nv-surface-3);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}

.lesson-action-bar {
  margin-top: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.825rem;
  color: var(--text-secondary);
}

.read-btn {
  color: var(--nv-green);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

/* ==========================================================================
   Reader View (Documentation View)
   ========================================================================== */

#reader-view {
  padding-top: var(--header-height);
  display: none;
  min-height: 100vh;
}

.reader-layout {
  display: flex;
  width: 100%;
}

/* Left Sidebar Navigation */
.sidebar-nav {
  width: var(--sidebar-width);
  height: calc(100vh - var(--header-height));
  position: fixed;
  top: var(--header-height);
  left: 0;
  background-color: var(--nv-surface-1);
  border-right: 1px solid var(--nv-border);
  overflow-y: auto;
  padding: 1.25rem 1rem;
  z-index: 100;
}

/* Sidebar Mobile Top Header (Folded with menu on narrow mobile screens) */
.sidebar-mobile-header {
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1rem;
  margin: -1.25rem -1rem 1.25rem -1rem;
  border-bottom: 1px solid var(--nv-border);
  background-color: var(--nv-surface-2);
}

.sidebar-mobile-header .mobile-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.sidebar-mobile-header .mobile-brand img {
  height: 24px;
}

.sidebar-mobile-header .mobile-brand .brand-title {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.sidebar-header-action {
  margin-bottom: 1.25rem;
}

.back-to-overview-btn {
  width: 100%;
  background-color: var(--nv-surface-2);
  border: 1px solid var(--nv-border);
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.back-to-overview-btn:hover {
  background-color: var(--nv-surface-3);
  color: var(--text-primary);
  border-color: var(--nv-border-light);
}

.sidebar-group {
  margin-bottom: 1.5rem;
}

.sidebar-group-title {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: 0.35rem 0.5rem;
  margin-bottom: 0.35rem;
}

.sidebar-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.sidebar-link:hover {
  background-color: var(--nv-surface-2);
  color: var(--text-primary);
  text-decoration: none;
}

.sidebar-link.active {
  background-color: rgba(118, 185, 0, 0.12);
  color: var(--nv-green);
  font-weight: 600;
  border-left: 3px solid var(--nv-green);
  box-shadow: inset 3px 0 10px rgba(118, 185, 0, 0.2);
  animation: activeGlowPulse 3s infinite ease-in-out;
}

@keyframes activeGlowPulse {
  0%, 100% {
    border-left-color: var(--nv-green);
    box-shadow: inset 3px 0 8px rgba(118, 185, 0, 0.2);
  }
  50% {
    border-left-color: #a6ff00;
    box-shadow: inset 4px 0 14px rgba(118, 185, 0, 0.45);
  }
}

/* Center Main Reader Content */
.main-reader {
  margin-left: var(--sidebar-width);
  margin-right: var(--toc-width);
  flex: 1;
  padding: 2.5rem 3.5rem;
  max-width: 1040px;
  margin-top: 0;
  min-height: calc(100vh - var(--header-height));
  box-sizing: border-box;
}

.reader-breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.reader-breadcrumb span {
  color: var(--text-secondary);
}

/* Markdown Rendered Styles */
.markdown-body {
  color: var(--text-primary);
  font-size: 1.025rem;
  line-height: 1.7;
}

.markdown-body h1 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--nv-border);
  padding-bottom: 0.75rem;
  color: var(--text-primary);
}

.markdown-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 2rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--nv-border);
}

.markdown-body h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

.markdown-body p {
  margin-bottom: 1.25rem;

}

.markdown-body ul, .markdown-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.markdown-body li {
  margin-bottom: 0.4rem;
}

.markdown-body li.task-checked {
  text-decoration: line-through;
  opacity: 0.65;
  transition: all 0.2s ease;
}

.markdown-body li input[type="checkbox"] {
  cursor: pointer;
  margin-right: 8px;
  transform: scale(1.15);
  accent-color: var(--nv-green);
  vertical-align: middle;
}

.markdown-body code:not([class*="language-"]) {
  font-family: var(--font-code);
  background-color: var(--nv-surface-2);
  color: var(--nv-green);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9em;
  border: 1px solid var(--nv-border);
}

/* Code Block Wrapper with Copy Button */
.code-block-wrapper {
  position: relative;
  margin: 1.5rem 0;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--nv-border);
  background-color: var(--nv-surface-1);
}

.code-header {
  background-color: var(--nv-surface-2);
  padding: 0.4rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Feishu Docs Style Code Block Component */
.feishu-code-block {
  margin: 1.5rem 0;
  border-radius: 8px;
  border: 1px solid var(--feishu-border);
  background-color: var(--feishu-bg);
  overflow: hidden;
  font-family: var(--font-main);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  transition: all 0.2s ease;
}

[data-theme="dark"] .feishu-code-block {
  --feishu-bg: #181c20;
  --feishu-header-bg: #1e2329;
  --feishu-border: #2d333b;
  --feishu-text: #e6edf3;
  --feishu-line-num: #6e7681;
}

[data-theme="light"] .feishu-code-block {
  --feishu-bg: #f5f6f7;
  --feishu-header-bg: #f5f6f7;
  --feishu-border: #dee0e3;
  --feishu-text: #1f2329;
  --feishu-line-num: #8f959e;
}

.feishu-code-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.55rem 1rem;
  background-color: var(--feishu-header-bg);
  font-size: 0.825rem;
  color: var(--feishu-line-num);
  user-select: none;
  border-bottom: 1px solid rgba(0, 0, 0, 0.03);
}

[data-theme="dark"] .feishu-code-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.feishu-code-header-left {
  display: flex;
  align-items: center;
  cursor: pointer;
  font-weight: 500;
  color: var(--feishu-line-num);
  transition: color 0.2s ease;
}

.feishu-code-header-left:hover {
  color: var(--feishu-text);
}

.feishu-caret {
  margin-right: 0.4rem;
  transition: transform 0.2s ease;
  font-size: 0.75rem;
}

.feishu-code-block.collapsed .feishu-caret {
  transform: rotate(-90deg);
}

.feishu-code-block.collapsed .feishu-code-body {
  display: none !important;
}

.feishu-code-header-right {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--feishu-line-num);
  font-size: 0.8rem;
  position: relative;
}

.feishu-lang-tag {
  color: var(--feishu-line-num);
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.25rem;
  cursor: pointer;
  padding: 0.2rem 0.45rem;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.feishu-lang-tag:hover,
.feishu-lang-tag.active {
  color: var(--feishu-text);
  background-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .feishu-lang-tag:hover,
[data-theme="dark"] .feishu-lang-tag.active {
  background-color: rgba(255, 255, 255, 0.08);
}

.feishu-lang-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: 0.35rem;
  width: 200px;
  max-height: 260px;
  background-color: var(--feishu-dropdown-bg);
  border: 1px solid var(--feishu-border);
  border-radius: 8px;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
  z-index: 100;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  font-family: var(--font-main);
}

[data-theme="dark"] .feishu-lang-dropdown {
  --feishu-dropdown-bg: #22272e;
}

[data-theme="light"] .feishu-lang-dropdown {
  --feishu-dropdown-bg: #ffffff;
}

.feishu-lang-search-wrap {
  padding: 0.5rem;
  border-bottom: 1px solid var(--feishu-border);
}

.feishu-lang-search {
  width: 100%;
  padding: 0.35rem 0.6rem;
  font-size: 0.8rem;
  border: 1px solid var(--feishu-border);
  border-radius: 4px;
  outline: none;
  background-color: var(--feishu-bg);
  color: var(--feishu-text);
  font-family: var(--font-main);
}

.feishu-lang-list {
  flex: 1;
  overflow-y: auto;
  padding: 0.25rem 0;
  margin: 0;
  list-style: none;
}

.feishu-lang-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.45rem 0.85rem;
  font-size: 0.825rem;
  color: var(--feishu-text);
  cursor: pointer;
  transition: background 0.15s ease;
}

.feishu-lang-item:hover {
  background-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .feishu-lang-item:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.feishu-lang-item.selected {
  color: var(--nv-green);
  font-weight: 600;
}

.feishu-divider {
  color: var(--feishu-line-num);
  opacity: 0.4;
  font-size: 0.75rem;
}

.feishu-action-btn {
  background: transparent;
  border: none;
  color: var(--feishu-line-num);
  font-size: 0.8rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.45rem;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.feishu-action-btn:hover {
  color: var(--feishu-text);
  background-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .feishu-action-btn:hover {
  background-color: rgba(255, 255, 255, 0.08);
}

.feishu-action-btn.active {
  color: var(--nv-green);
  font-weight: 600;
}

.feishu-code-body {
  display: flex;
  padding: 0.75rem 0 0.5rem 0;
  overflow: hidden;
  align-items: flex-start;
}

.feishu-line-numbers {
  display: flex;
  flex-direction: column;
  padding: 0 0.85rem 0 1rem;
  min-width: 2.2rem;
  text-align: right;
  color: var(--feishu-line-num);
  user-select: none;
  font-family: var(--font-code);
  font-size: 0.85rem;
  line-height: 1.6;
  margin: 0;
  flex-shrink: 0;
}

.feishu-line-numbers span {
  display: block;
  height: 1.6em;
  line-height: 1.6em;
}

.feishu-code-content {
  flex: 1;
  overflow-x: auto;
  padding-right: 1rem;
  padding-bottom: 0.5rem;
}

.feishu-code-content pre {
  margin: 0 !important;
  padding: 0 !important;
  background: transparent !important;
  border: none !important;
  box-shadow: none !important;
  font-family: var(--font-code) !important;
  font-size: 0.85rem !important;
  line-height: 1.6 !important;
  color: var(--feishu-text) !important;
  white-space: pre;
  overflow: visible !important;
}

/* Ultra-Thin Micro Scrollbar for Feishu Code Blocks */
.feishu-code-content {
  scrollbar-width: thin;
  scrollbar-color: rgba(140, 145, 155, 0.3) transparent;
}

.feishu-code-content::-webkit-scrollbar {
  height: 4px;
  width: 4px;
  background-color: transparent;
}

.feishu-code-content::-webkit-scrollbar-track {
  background: transparent;
}

.feishu-code-content::-webkit-scrollbar-thumb {
  background: rgba(140, 145, 155, 0.25);
  border-radius: 10px;
  transition: background-color 0.2s ease;
}

.feishu-code-content::-webkit-scrollbar-thumb:hover {
  background: rgba(141, 195, 31, 0.6);
}

[data-theme="dark"] .feishu-code-content::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
}

[data-theme="dark"] .feishu-code-content::-webkit-scrollbar-thumb:hover {
  background: var(--nv-green);
}

.feishu-code-content pre code {
  font-family: inherit !important;
  font-size: inherit !important;
  line-height: inherit !important;
  background: transparent !important;
  padding: 0 !important;
  border: none !important;
}

.feishu-code-content pre.word-wrap,
.feishu-code-content pre.word-wrap code {
  white-space: pre-wrap !important;
  word-break: break-all !important;
}

/* GitHub Alerts Callouts with Shimmering Gradient & Light Sweep Sheen */
.callout-box {
  position: relative;
  overflow: hidden;
  padding: 1rem 1.25rem 1rem 1.4rem;
  border-left: 4px solid var(--nv-border);
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
  background-color: var(--nv-surface-2);
}

.callout-box::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.05), transparent);
  transform: translateX(-100%);
  animation: calloutLightSweep 8s infinite ease-in-out;
  pointer-events: none;
}

@keyframes calloutLightSweep {
  0% { transform: translateX(-100%); }
  25% { transform: translateX(100%); }
  100% { transform: translateX(100%); }
}

.callout-box.note {
  background-color: var(--alert-note-bg);
  border-left-color: var(--alert-note-border);
}

.callout-box.warning {
  background-color: var(--alert-warn-bg);
  border-left-color: var(--alert-warn-border);
}

.callout-box.caution {
  background-color: var(--alert-caution-bg);
  border-left-color: var(--alert-caution-border);
}

.callout-title {
  font-weight: 700;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
}

.callout-box.note .callout-title { color: var(--alert-note-border); }
.callout-box.warning .callout-title { color: var(--alert-warn-border); }
.callout-box.caution .callout-title { color: var(--alert-caution-border); }

/* Tables in Markdown */
.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.925rem;
}

.markdown-body th, .markdown-body td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--nv-border);
  text-align: left;
}

.markdown-body th {
  background-color: var(--nv-surface-2);
  font-weight: 700;
}

.markdown-body tr:nth-child(even) {
  background-color: var(--nv-surface-1);
}

/* Images in Markdown */
.markdown-body img {
  max-width: 75%;
  height: auto;
  display: block;
  margin: 1.5rem auto;
  border-radius: 8px;
  border: 1px solid var(--nv-border);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
  cursor: zoom-in;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.markdown-body img:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

/* Pagination Footer */
.reader-pagination {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--nv-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.pag-btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.25rem;
  background-color: var(--nv-surface-1);
  border: 1px solid var(--nv-border);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  min-width: 160px;
  max-width: 48%;
}

.pag-btn.prev-btn {
  justify-content: flex-start;
  text-align: left;
}

.pag-btn.next-btn {
  justify-content: flex-end;
  text-align: right;
  margin-left: auto;
}

.pag-btn:hover {
  border-color: var(--nv-green);
  background-color: var(--nv-surface-2);
}

.pag-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.pag-title i {
  color: var(--nv-green);
  transition: transform 0.2s ease;
}

.pag-btn.prev-btn:hover .pag-title i {
  transform: translateX(-3px);
}

.pag-btn.next-btn:hover .pag-title i {
  transform: translateX(3px);
}

/* Right Sidebar (On This Page TOC) */
.toc-nav {
  width: var(--toc-width);
  height: calc(100vh - var(--header-height));
  position: fixed;
  top: var(--header-height);
  right: 0;
  padding: 2.5rem 1.25rem;
  overflow-y: auto;
}

.toc-title {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 1rem;
}

.toc-list {
  list-style: none;
  font-size: 0.825rem;
  border-left: 1px solid var(--nv-border);
}

.toc-item {
  margin-bottom: 0.4rem;
}

.toc-link {
  color: var(--text-secondary);
  display: block;
  padding: 0.3rem 0 0.3rem 1rem;
  border-left: 2px solid transparent;
  margin-left: -1px;
  border-radius: 0 4px 4px 0;
  transition: color 0.2s ease, border-left-color 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), padding-left 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), background-color 0.2s ease;
}

.toc-link:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.toc-link.active {
  color: var(--nv-green);
  font-weight: 600;
  border-left-color: var(--nv-green);
  padding-left: 1.25rem;
  background: linear-gradient(90deg, rgba(118, 185, 0, 0.12), transparent 90%);
}

/* ==========================================================================
   Modals & Lightbox
   ========================================================================== */

/* Search Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  z-index: 2000;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding-top: 10vh;
}

.modal-container {
  background-color: var(--nv-surface-1);
  border: 1px solid var(--nv-border-light);
  border-radius: 12px;
  width: 90%;
  max-width: 650px;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
}

.search-input-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--nv-border);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.search-input-header i {
  color: var(--nv-green);
  font-size: 1.2rem;
}

.search-input-field {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1.1rem;
  outline: none;
}

.search-results-list {
  max-height: 420px;
  overflow-y: auto;
  padding: 0.5rem;
}

.search-result-card {
  padding: 0.85rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 0.25rem;
  transition: background-color 0.2s ease;
}

.search-result-card:hover {
  background-color: var(--nv-surface-2);
}

.search-result-title {
  font-weight: 600;
  color: var(--nv-green);
  margin-bottom: 0.2rem;
  font-size: 0.95rem;
}

.search-result-snippet {
  font-size: 0.825rem;
  color: var(--text-secondary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Image Lightbox Modal with Spring Scale & Backdrop Blur */
#image-lightbox {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.82);
  backdrop-filter: blur(0px);
  z-index: 3000;
  display: flex;
  opacity: 0;
  visibility: hidden;
  align-items: center;
  justify-content: center;
  cursor: zoom-out;
  transition: opacity 0.3s ease, visibility 0.3s ease, backdrop-filter 0.3s ease;
}

#image-lightbox.active {
  opacity: 1;
  visibility: visible;
  backdrop-filter: blur(14px);
}

#image-lightbox img {
  max-width: 92vw;
  max-height: 92vh;
  border-radius: 10px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.85);
  transform: scale(0.88);
  opacity: 0;
  transition: transform 0.38s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
}

#image-lightbox.active img {
  transform: scale(1);
  opacity: 1;
}

/* Mobile Menu Button & TOC Button */
.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--nv-border);
  color: var(--text-primary);
  width: 36px;
  height: 36px;
  border-radius: 6px;
  font-size: 1.05rem;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  margin-right: 0.5rem;
  transition: all 0.2s ease;
}

.mobile-menu-btn:hover {
  background-color: var(--nv-surface-2);
  border-color: var(--nv-green);
  color: var(--nv-green);
}

#toc-toggle-btn {
  display: none;
}

body.in-landing-view #toc-toggle-btn {
  display: none !important;
}

.search-icon-compact {
  display: none;
}

/* Sidebar Backdrop Overlay */
.sidebar-overlay {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(2px);
  z-index: 190;
  display: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
  display: block;
  opacity: 1;
}

/* Responsive Media Queries */
@media (min-width: 1600px) {
  .main-reader {
    max-width: 1200px;
    padding: 3rem 5rem;
  }
}

/* Laptop Screen Responsive Breakpoint (Collapse ON THIS PAGE TOC) */
@media (max-width: 1400px) {
  body.in-reader-view #toc-toggle-btn {
    display: flex !important;
  }

  .main-reader {
    margin-right: 0 !important;
  }

  /* Right TOC Slide-out Drawer for Laptops & Mobile */
  .toc-nav {
    position: fixed;
    top: var(--header-height);
    right: 0;
    width: 270px;
    height: calc(100vh - var(--header-height));
    z-index: 200;
    background-color: var(--nv-surface-1);
    border-left: 1px solid var(--nv-border);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -6px 0 30px rgba(0, 0, 0, 0.35);
    display: block !important;
  }

  .toc-nav.drawer-open {
    transform: translateX(0);
  }
}

@media (max-width: 1100px) {
  .brand-subtitle {
    display: none !important;
  }

  .mobile-menu-btn {
    display: flex;
  }

  /* Completely hide mobile menu button on landing page */
  body.in-landing-view .mobile-menu-btn {
    display: none !important;
  }

  /* Compact Search Bar */
  .search-trigger-btn {
    width: 38px;
    height: 38px;
    padding: 0;
    justify-content: center;
    border-radius: 8px;
  }

  .search-text-full,
  .kbd-shortcut {
    display: none !important;
  }

  .search-icon-compact {
    display: block;
    color: var(--nv-green);
    font-size: 0.95rem;
  }

  /* Left Sidebar Slide-out Drawer */
  .sidebar-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 290px;
    height: calc(100vh - var(--header-height));
    z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 6px 0 30px rgba(0, 0, 0, 0.35);
  }

  .sidebar-nav.drawer-open {
    transform: translateX(0);
  }

  .main-reader {
    margin-left: 0 !important;
    margin-right: 0 !important;
    padding: 2rem 1.5rem;
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }

  /* Show Logo & Theme Toggle at top of left sidebar drawer on mobile */
  .sidebar-mobile-header {
    display: flex !important;
  }
}

/* Floating Back-to-Top Button (Low-key & Translucent Glassmorphism) */
.back-to-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(25, 30, 35, 0.75);
  backdrop-filter: blur(8px);
  border: 1px solid var(--nv-border);
  color: var(--text-secondary);
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 250;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease, background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.back-to-top-btn.visible {
  opacity: 0.75;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top-btn:hover {
  opacity: 1;
  background: var(--nv-surface-3);
  color: var(--nv-green);
  border-color: rgba(118, 185, 0, 0.4);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4), 0 0 10px rgba(118, 185, 0, 0.15);
}

/* Staggered Scroll-Reveal Animations */
.scroll-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}

.scroll-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* Markdown Responsive Table Scrollbar Wrapper */
.markdown-body .table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin-bottom: 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--nv-border);
}

.markdown-body .table-wrapper table {
  margin-bottom: 0 !important;
  border: none !important;
}

/* Markdown Image Loading & Cursor Indicator */
.markdown-body img {
  cursor: zoom-in;
  transition: opacity 0.3s ease, transform 0.2s ease;
}

/* Reading Metrics Badge (Reading Time & Word Count) */
.reading-metrics-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: -0.5rem;
  margin-bottom: 1.75rem;
  padding: 0.3rem 0.8rem;
  background-color: var(--nv-surface-2);
  border: 1px solid var(--nv-border);
  border-radius: 20px;
  font-weight: 500;
}

.reading-metrics-tag .metric-item {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.reading-metrics-tag .metric-item i {
  color: var(--nv-green);
  font-size: 0.8rem;
}

.reading-metrics-tag .metric-divider {
  opacity: 0.4;
  color: var(--text-muted);
}

/* Copy Code Button Toast/Tooltip */
.copy-code-btn.copied {
  background: rgba(118, 185, 0, 0.2) !important;
  color: var(--nv-green) !important;
  border-color: var(--nv-green) !important;
}

/* Glowing Top Reading Progress Bar */
.reading-progress-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--nv-green), #a6ff00);
  box-shadow: 0 0 10px rgba(118, 185, 0, 0.8);
  transition: width 0.15s ease-out;
  z-index: 105;
}