/* ==========================================================================
   CXK — Vaga Design System CSS (vg-html v3.5)
   Trợ lý AI Cơ Xương Khớp Tuổi Bạc (CXK)
   Tuân thủ Material Design 3 Flat Tonal Surfaces & Accessibility-First
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Work+Sans:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;1,400;1,600&display=swap');

/* --- 1. Root Tokens & Palette (Light Mode Default) --- */
:root {
  /* Brand Colors */
  --vaga-primary: #006949;           /* Vaga Deep Emerald */
  --vaga-primary-dark: #004d36;      /* Dark Green for Titles */
  --vaga-primary-light: #10b981;     /* Vibrant Mint Accent */
  --vaga-primary-bg: #e8f5f0;        /* Light Emerald Tint */
  --vaga-on-primary: #ffffff;

  --vaga-accent: #f26121;            /* Vaga Energetic Orange */
  --vaga-accent-dark: #c0430e;
  --vaga-accent-light: #ff922b;
  --vaga-accent-bg: #fff1eb;         /* Light Orange Tint */
  --vaga-on-accent: #ffffff;

  --vaga-light-green: #8cb820;       /* Vaga Spring Green */
  --vaga-light-green-bg: #f4fae6;

  /* Surfaces & Backgrounds */
  --vaga-bg-body: #f8f6f0;           /* Vaga Warm Beige */
  --vaga-bg-card: #ffffff;           /* Pure White Surface */
  --vaga-bg-elevated: #ffffff;
  --vaga-bg-sidebar: #f0ece1;
  --vaga-bg-hover: rgba(0, 105, 73, 0.06);
  --vaga-bg-active: rgba(0, 105, 73, 0.12);

  /* Borders & Dividers */
  --vaga-border: #e2ded5;            /* Warm subtle border */
  --vaga-border-focus: #006949;

  /* Text & Typography */
  --vaga-text-primary: #1a2e26;      /* High contrast dark green-gray */
  --vaga-text-secondary: #4a5d54;    /* Supporting body text */
  --vaga-text-muted: #74877e;        /* Captions, metadata */
  --vaga-text-inverse: #ffffff;

  /* Semantic Feedback */
  --vaga-success: #15803d;
  --vaga-success-bg: #dcfce7;
  --vaga-warning: #b45309;
  --vaga-warning-bg: #fef3c7;
  --vaga-danger: #b91c1c;
  --vaga-danger-bg: #fee2e2;
  --vaga-info: #0369a1;
  --vaga-info-bg: #e0f2fe;

  /* MD3 Shape Scale */
  --vaga-radius-xs: 4px;
  --vaga-radius-sm: 8px;
  --vaga-radius-md: 12px;
  --vaga-radius-lg: 16px;
  --vaga-radius-xl: 24px;
  --vaga-radius-pill: 9999px;

  /* Elevation Shadows (Restrained MD3) */
  --vaga-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --vaga-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.07);
  --vaga-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);

  /* Transitions & Motion */
  --duration-short: 150ms;
  --duration-normal: 250ms;
  --ease-standard: cubic-bezier(0.2, 0, 0, 1);
  --ease-emphasized: cubic-bezier(0.05, 0.7, 0.1, 1);
}

/* --- 2. Dark Mode Override ([data-theme="dark"]) --- */
[data-theme="dark"] {
  --vaga-primary: #34d399;           /* Vibrant Emerald */
  --vaga-primary-dark: #6ee7b7;
  --vaga-primary-light: #059669;
  --vaga-primary-bg: #064e3b;
  --vaga-on-primary: #042f2e;

  --vaga-accent: #fbbf24;            /* Amber Glow */
  --vaga-accent-dark: #f59e0b;
  --vaga-accent-light: #fde68a;
  --vaga-accent-bg: #451a03;
  --vaga-on-accent: #451a03;

  --vaga-light-green: #a3e635;
  --vaga-light-green-bg: #1e3a12;

  --vaga-bg-body: #0f172a;           /* Deep Slate Blue */
  --vaga-bg-card: #1e293b;           /* Slate Surface */
  --vaga-bg-elevated: #273549;
  --vaga-bg-sidebar: #131d2e;
  --vaga-bg-hover: rgba(52, 211, 153, 0.1);
  --vaga-bg-active: rgba(52, 211, 153, 0.18);

  --vaga-border: #334155;
  --vaga-border-focus: #34d399;

  --vaga-text-primary: #f8fafc;
  --vaga-text-secondary: #cbd5e1;
  --vaga-text-muted: #94a3b8;
  --vaga-text-inverse: #0f172a;

  --vaga-success: #4ade80;
  --vaga-success-bg: #14532d;
  --vaga-warning: #facc15;
  --vaga-warning-bg: #713f12;
  --vaga-danger: #f87171;
  --vaga-danger-bg: #7f1d1d;
  --vaga-info: #38bdf8;
  --vaga-info-bg: #0c4a6e;

  --vaga-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --vaga-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --vaga-shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.55);
}

/* --- 3. Senior Accessibility Font Scaling --- */
html {
  font-size: 16px;
  scroll-behavior: smooth;
  box-sizing: border-box;
}

html[data-font-size="large"] {
  font-size: 18px; /* +12.5% for seniors */
}

html[data-font-size="xlarge"] {
  font-size: 20px; /* +25% for seniors */
}

*, *::before, *::after {
  box-sizing: inherit;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Work Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--vaga-text-primary);
  background-color: var(--vaga-bg-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Heading Anchor Scroll Margin (stops sticky nav overlapping) */
h1, h2, h3, h4, h5, h6 {
  scroll-margin-top: 84px;
  color: var(--vaga-primary-dark);
  font-weight: 700;
  line-height: 1.35;
  margin-top: 1.6em;
  margin-bottom: 0.6em;
}

[data-theme="dark"] h1,
[data-theme="dark"] h2,
[data-theme="dark"] h3,
[data-theme="dark"] h4 {
  color: var(--vaga-primary);
}

p {
  margin-top: 0;
  margin-bottom: 1.1em;
}

a {
  color: var(--vaga-primary);
  text-decoration: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
  transition: color var(--duration-short) var(--ease-standard);
}

a:hover {
  color: var(--vaga-accent);
}

/* --- 4. Reading Progress Bar --- */
.reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 0%;
  background: linear-gradient(90deg, var(--vaga-primary), var(--vaga-accent));
  z-index: 1001;
  transition: width 0.1s ease-out;
}

/* --- 5. Sticky Header & Navbar --- */
.vaga-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--vaga-bg-card);
  border-bottom: 1px solid var(--vaga-border);
  box-shadow: var(--vaga-shadow-sm);
  transition: background-color var(--duration-normal) var(--ease-standard),
              border-color var(--duration-normal) var(--ease-standard);
}

.navbar-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 8px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  flex-shrink: 0;
}

.brand-logo-img {
  height: 48px;
  width: auto;
  display: block;
}

/* Main Navigation Menu */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: nowrap;
}

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

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--vaga-text-secondary);
  text-decoration: none;
  border-radius: var(--vaga-radius-pill);
  transition: all var(--duration-short) var(--ease-standard);
  white-space: nowrap;
}

.nav-link:hover {
  background-color: var(--vaga-bg-hover);
  color: var(--vaga-primary);
  text-decoration: none;
}

.nav-link.active {
  background-color: var(--vaga-primary-bg);
  color: var(--vaga-primary-dark);
  font-weight: 700;
  border: 1px solid var(--vaga-border);
}

[data-theme="dark"] .nav-link.active {
  color: var(--vaga-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  flex-shrink: 0;
}

/* Buttons */
.vaga-btn, .btn-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--vaga-radius-pill);
  border: 1px solid var(--vaga-border);
  background-color: var(--vaga-bg-card);
  color: var(--vaga-text-primary);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--duration-short) var(--ease-standard);
  white-space: nowrap;
}

.vaga-btn:hover, .btn-action:hover {
  background-color: var(--vaga-bg-hover);
  border-color: var(--vaga-primary);
  color: var(--vaga-primary);
}

.btn-primary {
  background-color: var(--vaga-primary);
  border-color: var(--vaga-primary);
  color: var(--vaga-on-primary) !important;
}

.btn-primary:hover {
  background-color: var(--vaga-primary-dark);
  border-color: var(--vaga-primary-dark);
}

.btn-search-trigger {
  background-color: var(--vaga-bg-body);
  border: 1px solid var(--vaga-border);
  padding: 7px 16px;
  border-radius: var(--vaga-radius-pill);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  font-size: 0.875rem;
  color: var(--vaga-text-secondary);
}

.btn-search-trigger kbd {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: 0.75rem;
  font-family: monospace;
}

/* Font Resizer Controls */
.font-resizer-group {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-pill);
  overflow: hidden;
  background: var(--vaga-bg-card);
}

.font-btn {
  background: transparent;
  border: none;
  padding: 6px 10px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--vaga-text-secondary);
  cursor: pointer;
  transition: background-color var(--duration-short);
}

.font-btn:hover {
  background-color: var(--vaga-bg-hover);
  color: var(--vaga-primary);
}

.font-btn.active {
  background-color: var(--vaga-primary-bg);
  color: var(--vaga-primary);
}

/* --- 6. Breadcrumbs --- */
.breadcrumb-bar {
  background-color: var(--vaga-bg-sidebar);
  border-bottom: 1px solid var(--vaga-border);
  padding: 8px 24px;
}

.breadcrumb-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 0.875rem;
  color: var(--vaga-text-muted);
}

.breadcrumb-item a {
  color: var(--vaga-text-secondary);
  text-decoration: none;
  font-weight: 500;
}

.breadcrumb-item a:hover {
  color: var(--vaga-primary);
  text-decoration: underline;
}

.breadcrumb-separator {
  color: var(--vaga-text-muted);
  opacity: 0.7;
}

.breadcrumb-current {
  color: var(--vaga-text-primary);
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 400px;
}

/* --- 7. Main Layout (Two Column: Content + TOC) --- */
.main-wrapper {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px;
  flex: 1;
  width: 100%;
}

.layout-content-toc {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  align-items: start;
}

.layout-single-col {
  max-width: 1040px;
  margin: 0 auto;
}

/* Article Shell */
.vaga-article {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 40px;
  box-shadow: var(--vaga-shadow-sm);
  min-width: 0;
  overflow-wrap: anywhere;
}

.article-hero {
  border-bottom: 2px solid var(--vaga-border);
  padding-bottom: 24px;
  margin-bottom: 32px;
}

.badge-row {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: var(--vaga-radius-pill);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

.badge--primary {
  background: var(--vaga-primary-bg);
  color: var(--vaga-primary-dark);
  border: 1px solid var(--vaga-primary);
}

.badge--accent {
  background: var(--vaga-accent-bg);
  color: var(--vaga-accent-dark);
  border: 1px solid var(--vaga-accent);
}

.badge--success {
  background: var(--vaga-success-bg);
  color: var(--vaga-success);
  border: 1px solid var(--vaga-success);
}

.badge--danger, .badge--redflag {
  background: var(--vaga-danger-bg);
  color: var(--vaga-danger);
  border: 1px solid var(--vaga-danger);
}

.badge--muted {
  background: var(--vaga-bg-sidebar);
  color: var(--vaga-text-secondary);
  border: 1px solid var(--vaga-border);
}

.article-title {
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1.25;
  color: var(--vaga-primary-dark);
  margin: 0 0 16px 0;
  letter-spacing: -0.5px;
}

[data-theme="dark"] .article-title {
  color: var(--vaga-primary);
}

.article-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: var(--vaga-text-muted);
}

.article-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Article Body Typography */
.article-body {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--vaga-text-primary);
}

.article-body h2 {
  font-size: 1.6rem;
  border-bottom: 1px solid var(--vaga-border);
  padding-bottom: 8px;
  margin-top: 1.8em;
}

.article-body h3 {
  font-size: 1.3rem;
  margin-top: 1.5em;
}

.article-body h4 {
  font-size: 1.1rem;
}

.article-body ul, .article-body ol {
  padding-left: 28px;
  margin-bottom: 1.4em;
}

.article-body li {
  margin-bottom: 0.45em;
}

.article-body blockquote {
  margin: 1.5em 0;
  padding: 16px 20px;
  background-color: var(--vaga-primary-bg);
  border-left: 4px solid var(--vaga-primary);
  border-radius: 0 var(--vaga-radius-md) var(--vaga-radius-md) 0;
  font-style: italic;
  color: var(--vaga-text-primary);
}

.article-body blockquote p:last-child {
  margin-bottom: 0;
}

/* --- 8. Table of Contents (TOC) --- */
/* Collapsible in-body TOC */
details.vaga-toc {
  background: var(--vaga-primary-bg);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-md);
  padding: 16px 20px;
  margin: 24px 0 32px 0;
}

details.vaga-toc summary {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--vaga-primary-dark);
  cursor: pointer;
  list-style-type: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

[data-theme="dark"] details.vaga-toc summary {
  color: var(--vaga-primary);
}

details.vaga-toc summary::-webkit-details-marker {
  display: none;
}

details.vaga-toc summary::after {
  content: '▼';
  font-size: 0.8rem;
  transition: transform 0.2s;
}

details.vaga-toc[open] summary::after {
  transform: rotate(180deg);
}

.vaga-toc-nav ul {
  list-style: none;
  padding-left: 0;
  margin: 14px 0 0 0;
}

.vaga-toc-item {
  margin-bottom: 6px;
}

.vaga-toc-item a {
  text-decoration: none;
  color: var(--vaga-text-secondary);
  font-size: 0.92rem;
  display: block;
  padding: 3px 0;
}

.vaga-toc-item a:hover {
  color: var(--vaga-primary);
  text-decoration: underline;
}

.vaga-toc-item.level-3 {
  padding-left: 18px;
  font-size: 0.85rem;
}

.vaga-toc-item.level-4 {
  padding-left: 32px;
  font-size: 0.8rem;
}

/* Sticky Sidebar TOC (Desktop) */
.toc-sidebar {
  position: sticky;
  top: 96px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 20px;
  box-shadow: var(--vaga-shadow-sm);
}

.toc-sidebar-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--vaga-primary-dark);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin: 0 0 12px 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

[data-theme="dark"] .toc-sidebar-title {
  color: var(--vaga-primary);
}

.toc-sidebar-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.toc-sidebar-list a {
  display: block;
  padding: 5px 8px;
  border-radius: var(--vaga-radius-xs);
  color: var(--vaga-text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  line-height: 1.4;
  transition: all var(--duration-short);
}

.toc-sidebar-list a:hover {
  background-color: var(--vaga-bg-hover);
  color: var(--vaga-primary);
}

.toc-sidebar-list .level-3 a {
  padding-left: 20px;
  font-size: 0.8rem;
}

/* --- 9. Responsive Tables --- */
.vaga-table-wrapper {
  width: 100%;
  overflow-x: auto;
  margin: 24px 0;
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-md);
  background: var(--vaga-bg-card);
  box-shadow: var(--vaga-shadow-sm);
}

table.vaga-table, .article-body table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  text-align: left;
}

table.vaga-table th, .article-body table th {
  background-color: var(--vaga-primary-bg);
  color: var(--vaga-primary-dark);
  font-weight: 700;
  padding: 12px 16px;
  border-bottom: 2px solid var(--vaga-border);
  white-space: nowrap;
}

[data-theme="dark"] table.vaga-table th,
[data-theme="dark"] .article-body table th {
  color: var(--vaga-primary);
}

table.vaga-table td, .article-body table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--vaga-border);
  vertical-align: top;
}

table.vaga-table tr:last-child td, .article-body table tr:last-child td {
  border-bottom: none;
}

table.vaga-table tbody tr:hover, .article-body table tbody tr:hover {
  background-color: var(--vaga-bg-hover);
}

/* --- 10. Code & Code Blocks --- */
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.88em;
  background-color: var(--vaga-bg-sidebar);
  color: var(--vaga-accent-dark);
  padding: 2px 6px;
  border-radius: var(--vaga-radius-xs);
  border: 1px solid var(--vaga-border);
}

[data-theme="dark"] code {
  color: var(--vaga-accent);
}

pre {
  background-color: #1e293b;
  color: #f8fafc;
  padding: 18px 22px;
  border-radius: var(--vaga-radius-md);
  overflow-x: auto;
  font-size: 0.88rem;
  line-height: 1.55;
  margin: 20px 0;
  border: 1px solid var(--vaga-border);
}

pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  border: none;
  font-size: inherit;
}

/* --- 11. Disclaimer & Callout Boxes --- */
.disclaimer-box {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 20px;
  background-color: var(--vaga-warning-bg);
  border: 1px solid #fcd34d;
  border-radius: var(--vaga-radius-md);
  margin: 32px 0 20px 0;
}

[data-theme="dark"] .disclaimer-box {
  border-color: var(--vaga-warning);
}

.disclaimer-icon {
  font-size: 1.8rem;
  line-height: 1;
  flex-shrink: 0;
}

.disclaimer-content h4 {
  margin: 0 0 6px 0;
  font-size: 1rem;
  font-weight: 700;
  color: var(--vaga-warning);
}

.disclaimer-content p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--vaga-text-primary);
  line-height: 1.5;
}

.alert-box {
  padding: 16px 20px;
  border-radius: var(--vaga-radius-md);
  margin: 20px 0;
  border-left: 4px solid;
}

.alert-danger {
  background-color: var(--vaga-danger-bg);
  border-color: var(--vaga-danger);
  color: var(--vaga-danger);
}

.alert-info {
  background-color: var(--vaga-info-bg);
  border-color: var(--vaga-info);
  color: var(--vaga-info);
}

/* --- 12. Cards, KPI Grids, & Hub UI --- */
.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin: 24px 0 36px 0;
}

.kpi-card {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 22px;
  box-shadow: var(--vaga-shadow-sm);
  transition: border-color var(--duration-short) var(--ease-standard);
}

.kpi-card:hover {
  border-color: var(--vaga-primary);
}

.kpi-card-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--vaga-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.kpi-card-value {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.1;
  color: var(--vaga-primary);
  margin-bottom: 6px;
}

.kpi-card-desc {
  font-size: 0.85rem;
  color: var(--vaga-text-secondary);
}

/* Hero Section */
.hero-card {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-xl);
  padding: 40px;
  margin-bottom: 32px;
  box-shadow: var(--vaga-shadow-sm);
  position: relative;
  overflow: hidden;
}

.hero-title {
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--vaga-primary-dark);
  margin: 12px 0 16px 0;
}

[data-theme="dark"] .hero-title {
  color: var(--vaga-primary);
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--vaga-text-secondary);
  max-width: 900px;
  line-height: 1.6;
  margin-bottom: 24px;
}

.hero-meta-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  background-color: var(--vaga-primary-bg);
  padding: 20px;
  border-radius: var(--vaga-radius-md);
  border: 1px solid var(--vaga-border);
  font-size: 0.92rem;
}

.hero-meta-item span {
  color: var(--vaga-text-muted);
  font-weight: 500;
}

.hero-meta-item strong {
  color: var(--vaga-text-primary);
  display: block;
  margin-top: 2px;
}

/* Pillar Grid */
.pillar-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
  margin: 24px 0 40px 0;
}

.pillar-card {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 24px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: all var(--duration-short) var(--ease-standard);
  box-shadow: var(--vaga-shadow-sm);
}

.pillar-card:hover {
  border-color: var(--vaga-primary);
  background-color: var(--vaga-bg-hover);
}

.pillar-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.pillar-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--vaga-primary);
  margin: 0 0 8px 0;
}

.pillar-desc {
  font-size: 0.92rem;
  color: var(--vaga-text-secondary);
  line-height: 1.5;
  margin: 0;
  flex-grow: 1;
}

/* Document List Grid */
.doc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 16px;
  margin: 16px 0;
}

.doc-card {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-md);
  padding: 16px 20px;
  text-decoration: none;
  color: inherit;
  display: block;
  transition: border-color var(--duration-short);
}

.doc-card:hover {
  border-color: var(--vaga-primary);
  background-color: var(--vaga-bg-hover);
}

.doc-card-title {
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--vaga-text-primary);
  margin-bottom: 6px;
  line-height: 1.4;
}

.doc-card:hover .doc-card-title {
  color: var(--vaga-primary);
}

.doc-card-meta {
  font-size: 0.8rem;
  color: var(--vaga-text-muted);
  display: flex;
  gap: 8px;
}

/* --- 13. A-Z Index Pills & Directory --- */
.az-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 20px 0 32px 0;
  padding: 16px;
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
}

.az-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  font-weight: 700;
  font-size: 1rem;
  border-radius: var(--vaga-radius-md);
  background: var(--vaga-bg-sidebar);
  color: var(--vaga-text-primary);
  text-decoration: none;
  transition: all var(--duration-short);
}

.az-pill:hover, .az-pill.active {
  background: var(--vaga-primary);
  color: var(--vaga-on-primary);
}

.az-group {
  margin-bottom: 36px;
}

.az-letter-header {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--vaga-primary);
  border-bottom: 2px solid var(--vaga-primary);
  padding-bottom: 6px;
  margin-bottom: 16px;
}

/* --- 14. Live Search & Filter Modal --- */
.search-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
  z-index: 2000;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-normal);
}

.search-backdrop.is-active {
  opacity: 1;
  pointer-events: auto;
}

.search-modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.96);
  width: 720px;
  max-width: 92vw;
  max-height: 80vh;
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-xl);
  box-shadow: var(--vaga-shadow-lg);
  z-index: 2001;
  display: flex;
  flex-direction: column;
  opacity: 0;
  pointer-events: none;
  transition: all var(--duration-normal) var(--ease-emphasized);
}

.search-modal.is-active {
  opacity: 1;
  pointer-events: auto;
  transform: translate(-50%, -50%) scale(1);
}

.search-header {
  display: flex;
  align-items: center;
  padding: 16px 20px;
  border-bottom: 1px solid var(--vaga-border);
  gap: 12px;
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 1.1rem;
  background: transparent;
  color: var(--vaga-text-primary);
}

.search-input::placeholder {
  color: var(--vaga-text-muted);
}

.search-body {
  padding: 16px 20px;
  overflow-y: auto;
  flex: 1;
}

.search-results-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.search-result-item {
  padding: 12px 14px;
  border-radius: var(--vaga-radius-md);
  border: 1px solid var(--vaga-border);
  text-decoration: none;
  color: inherit;
  display: block;
  transition: background-color var(--duration-short);
}

.search-result-item:hover {
  background-color: var(--vaga-bg-hover);
  border-color: var(--vaga-primary);
}

.search-result-title {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--vaga-primary);
  margin-bottom: 4px;
}

.search-result-desc {
  font-size: 0.85rem;
  color: var(--vaga-text-secondary);
  line-height: 1.4;
}

.search-footer {
  padding: 12px 20px;
  border-top: 1px solid var(--vaga-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--vaga-text-muted);
  background: var(--vaga-bg-sidebar);
  border-radius: 0 0 var(--vaga-radius-xl) var(--vaga-radius-xl);
}

/* --- 15. Back to Top Button --- */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 999;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--vaga-primary);
  color: #ffffff;
  border: none;
  font-size: 1.3rem;
  font-weight: 800;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--vaga-shadow-md);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-normal), transform var(--duration-short);
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background-color: var(--vaga-accent);
  transform: translateY(-2px);
}

/* --- 16. Article Navigation Footer --- */
.article-nav-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--vaga-border);
  flex-wrap: wrap;
}

/* --- 17. Footer --- */
.vaga-footer {
  background-color: var(--vaga-bg-card);
  border-top: 1px solid var(--vaga-border);
  margin-top: auto;
  padding: 48px 24px 24px 24px;
}

.footer-container {
  max-width: 1400px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}

.footer-brand h3 {
  color: var(--vaga-primary);
  margin: 0 0 10px 0;
  font-size: 1.3rem;
}

.footer-brand p {
  color: var(--vaga-text-secondary);
  font-size: 0.92rem;
  line-height: 1.55;
  margin: 0;
}

.footer-col h4 {
  color: var(--vaga-primary-dark);
  font-size: 0.95rem;
  font-weight: 700;
  margin: 0 0 16px 0;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

[data-theme="dark"] .footer-col h4 {
  color: var(--vaga-primary);
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--vaga-text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
}

.footer-col a:hover {
  color: var(--vaga-primary);
  text-decoration: underline;
}

.footer-bottom {
  max-width: 1400px;
  margin: 0 auto;
  padding-top: 20px;
  border-top: 1px solid var(--vaga-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--vaga-text-muted);
  flex-wrap: wrap;
  gap: 12px;
}

/* --- 18. Responsive Media Queries --- */
@media (max-width: 1200px) {
  .navbar-container {
    flex-wrap: wrap;
    padding: 8px 16px;
    gap: 10px;
  }
  .nav-menu {
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding: 6px 0 2px 0;
    border-top: 1px solid var(--vaga-border);
    -webkit-overflow-scrolling: touch;
  }
  .nav-menu::-webkit-scrollbar {
    height: 3px;
  }
  .nav-menu::-webkit-scrollbar-thumb {
    background: var(--vaga-border);
    border-radius: 4px;
  }
}

@media (max-width: 1080px) {
  .layout-content-toc {
    grid-template-columns: 1fr;
  }
  .toc-sidebar {
    display: none; /* In-body details.vaga-toc takes over */
  }
  .footer-container {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .vaga-article {
    padding: 24px 18px;
  }
  .article-title {
    font-size: 1.6rem;
  }
  .hero-card {
    padding: 24px 18px;
  }
  .hero-title {
    font-size: 1.8rem;
  }
  .footer-container {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .nav-actions .btn-text-label {
    display: none;
  }
  .brand-logo-img {
    height: 38px;
  }
}

/* ==============================================================================
   12. GLOSSARY TERM & INTERACTIVE POPUP CARD SYSTEM (VAGA DESIGN SYSTEM)
   ============================================================================== */

/* Term Highlight in Article Text */
.vaga-glossary-term {
  border-bottom: 2px dotted var(--vaga-primary);
  color: inherit;
  cursor: help;
  position: relative;
  text-decoration: none;
  font-weight: 600;
  transition: all var(--duration-short) var(--ease-standard);
  border-radius: 2px;
  padding: 0 3px;
  display: inline;
}

.vaga-glossary-term:hover,
.vaga-glossary-term:focus-visible,
.vaga-glossary-term.is-active {
  background-color: rgba(16, 185, 129, 0.15);
  color: var(--vaga-primary-dark);
  border-bottom-style: solid;
  outline: none;
}

[data-theme="dark"] .vaga-glossary-term:hover,
[data-theme="dark"] .vaga-glossary-term:focus-visible,
[data-theme="dark"] .vaga-glossary-term.is-active {
  color: var(--vaga-primary);
  background-color: rgba(52, 211, 153, 0.18);
}

/* Floating Popup Card Component */
.vaga-glossary-popup {
  position: fixed;
  z-index: 1050;
  width: 330px;
  max-width: calc(100vw - 28px);
  background-color: var(--vaga-bg-card);
  color: var(--vaga-text-primary);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  box-shadow: var(--vaga-shadow-lg);
  padding: 14px 16px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px) scale(0.98);
  transition: opacity 0.18s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.18s cubic-bezier(0.4, 0, 0.2, 1),
              visibility 0.18s;
  pointer-events: none;
  font-family: inherit;
  font-size: 0.92rem;
  line-height: 1.5;
  box-sizing: border-box;
}

.vaga-glossary-popup.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

/* Popup Header */
.glossary-popup-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--vaga-border);
}

.glossary-popup-title-area {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex-grow: 1;
}

.glossary-popup-term-row {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.glossary-popup-icon {
  font-size: 1.15rem;
  line-height: 1;
}

.glossary-popup-term {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--vaga-primary-dark);
}

[data-theme="dark"] .glossary-popup-term {
  color: var(--vaga-primary);
}

.glossary-popup-en {
  font-size: 0.8rem;
  color: var(--vaga-text-muted);
  font-style: italic;
}

.glossary-popup-close {
  background: none;
  border: none;
  color: var(--vaga-text-muted);
  font-size: 1rem;
  cursor: pointer;
  padding: 2px 6px;
  border-radius: var(--vaga-radius-sm);
  line-height: 1;
  transition: all var(--duration-short);
}

.glossary-popup-close:hover {
  background-color: var(--vaga-bg-hover);
  color: var(--vaga-text-primary);
}

/* Popup Body */
.glossary-popup-body {
  margin-bottom: 10px;
}

.glossary-popup-desc {
  margin: 0;
  color: var(--vaga-text-secondary);
  font-size: 0.88rem;
  line-height: 1.45;
}

/* Popup Footer */
.glossary-popup-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 8px;
  border-top: 1px solid var(--vaga-border);
  font-size: 0.82rem;
}

.glossary-popup-link {
  color: var(--vaga-primary);
  text-decoration: none;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: color var(--duration-short);
}

.glossary-popup-link:hover {
  text-decoration: underline;
  color: var(--vaga-primary-dark);
}

/* Arrow Indicator */
.glossary-popup-arrow {
  position: absolute;
  width: 10px;
  height: 10px;
  background-color: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  transform: rotate(45deg);
  pointer-events: none;
}

.glossary-popup-arrow.arrow-top {
  top: -6px;
  border-bottom: none;
  border-right: none;
}

.glossary-popup-arrow.arrow-bottom {
  bottom: -6px;
  border-top: none;
  border-left: none;
}

/* 15. Highlight Target Row When Navigated from Glossary Popup */
tr:target {
  background-color: var(--vaga-primary-container) !important;
  color: var(--vaga-on-primary-container) !important;
  outline: 2.5px solid var(--vaga-primary);
  outline-offset: -2px;
  border-radius: var(--vaga-radius-sm);
  transition: background-color 0.4s ease, outline 0.4s ease;
  animation: vagaHighlightPulse 1.8s ease-in-out;
}

@keyframes vagaHighlightPulse {
  0% {
    box-shadow: 0 0 0 0 rgba(0, 106, 96, 0.4);
  }
  50% {
    box-shadow: 0 0 0 8px rgba(0, 106, 96, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(0, 106, 96, 0);
  }
}

/* 16. Chart.js Data Visualizations (Vaga Design System) */
.chart-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 24px;
  margin: 28px 0;
}

@media (max-width: 768px) {
  .chart-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
}

.chart-card {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 24px;
  box-shadow: var(--vaga-shadow-sm);
  display: flex;
  flex-direction: column;
  transition: transform var(--duration-normal) var(--ease-standard), box-shadow var(--duration-normal) var(--ease-standard);
  position: relative;
}

.chart-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--vaga-shadow-md);
}

.chart-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 16px;
  flex-wrap: wrap;
  gap: 8px;
}

.chart-card-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--vaga-primary-dark);
  margin: 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

[data-theme="dark"] .chart-card-title {
  color: var(--vaga-primary);
}

.chart-card-subtitle {
  font-size: 0.85rem;
  color: var(--vaga-text-muted);
  margin-top: 4px;
}

.chart-card-body {
  position: relative;
  width: 100%;
  min-height: 280px;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chart-card-body canvas {
  max-width: 100% !important;
  max-height: 320px !important;
}

.chart-card-footer {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px dashed var(--vaga-border);
  font-size: 0.82rem;
  color: var(--vaga-text-muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

/* 17. Mermaid Diagram Container & Theming */
.vaga-mermaid-wrapper {
  background: var(--vaga-bg-card);
  border: 1px solid var(--vaga-border);
  border-radius: var(--vaga-radius-lg);
  padding: 24px 20px;
  margin: 28px 0;
  box-shadow: var(--vaga-shadow-sm);
  overflow-x: auto;
  text-align: center;
  position: relative;
}

.vaga-mermaid-wrapper .mermaid {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 120px;
  font-family: var(--vaga-font-family, 'Work Sans', system-ui, sans-serif);
}

.vaga-mermaid-wrapper svg {
  max-width: 100% !important;
  height: auto !important;
}

.vaga-mermaid-caption {
  font-size: 0.85rem;
  color: var(--vaga-text-muted);
  margin-top: 14px;
  font-weight: 500;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

[data-theme="dark"] .vaga-mermaid-wrapper {
  background: var(--vaga-bg-card);
  border-color: var(--vaga-border);
}