/* ═══════════════════════════════════════════════════════════════
   RESOURCES ML — Adapted to AlphaVault Drive design system
   File: assets/css/resources-ml.css
   ═══════════════════════════════════════════════════════════════ */

/* ════════════════════════════════════════════════════════════
   DRIVE CSS VARIABLES (light mode default)
════════════════════════════════════════════════════════════ */
:root {
    --avd-bg:             #f1f5f9;
    --avd-sidebar-bg:     #ffffff;
    --avd-header-bg:      rgba(255, 255, 255, 0.97);
    --avd-card:           #ffffff;
    --avd-card-hover:     #f8fafc;
    --avd-input-bg:       rgba(0, 0, 0, 0.04);
    --avd-border:         rgba(0, 0, 0, 0.08);
    --avd-border-hover:   rgba(0, 0, 0, 0.15);
    --avd-text:           #1e293b;
    --avd-text-muted:     #475569;
    --avd-text-dim:       #94a3b8;
    --avd-primary:        #667eea;
    --avd-primary-dark:   #764ba2;
    --avd-green:          #10b981;
    --avd-amber:          #f59e0b;
    --avd-red:            #ef4444;
    --avd-purple:         #8b5cf6;
    --avd-radius:         10px;
    --avd-radius-lg:      16px;
    --avd-radius-xl:      24px;
    --avd-shadow:         0 4px 24px rgba(0,0,0,0.10);
    --avd-shadow-lg:      0 10px 50px rgba(0,0,0,0.15);
    --avd-sidebar-w:      260px;
    --avd-header-h:       58px;
  }
  
  /* Dark mode override */
  body.avd-page:not(.light-mode) {
    --avd-bg:             #0b1120;
    --avd-sidebar-bg:     #0f172a;
    --avd-header-bg:      rgba(11, 17, 32, 0.97);
    --avd-card:           rgba(30, 41, 59, 0.92);
    --avd-card-hover:     rgba(51, 65, 85, 0.9);
    --avd-input-bg:       rgba(255, 255, 255, 0.06);
    --avd-border:         rgba(255, 255, 255, 0.08);
    --avd-border-hover:   rgba(255, 255, 255, 0.15);
    --avd-text:           #f0f4f8;
    --avd-text-muted:     #cbd5e1;
    --avd-text-dim:       #94a3b8;
    --avd-shadow:         0 4px 24px rgba(0,0,0,0.35);
    --avd-shadow-lg:      0 10px 50px rgba(0,0,0,0.55);
  }
  
  /* ════════════════════════════════════════════════════════════
     RESET & BASE
  ════════════════════════════════════════════════════════════ */
  *, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  html, body {
    height: 100%;
    overflow: hidden;
  }
  
  body.avd-page {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--avd-bg);
    color: var(--avd-text);
    font-size: 13px;
    -webkit-font-smoothing: antialiased;
    line-height: 1.5;
  }
  
  a { color: inherit; text-decoration: none; }
  button { font-family: inherit; }
  
  /* ════════════════════════════════════════════════════════════
     APP LAYOUT
  ════════════════════════════════════════════════════════════ */
  #avDriveApp {
    display: flex;
    height: 100vh;
    overflow: hidden;
    position: relative;
  }
  
  /* ── SIDEBAR ──────────────────────────────────────────────── */
  #avdSidebar {
    width: var(--avd-sidebar-w);
    flex-shrink: 0;
    background: var(--avd-sidebar-bg);
    border-right: 1px solid var(--avd-border);
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: visible;
    position: relative;
    z-index: 200;
  }
  
  body.light-mode #avdSidebar {
    box-shadow: 2px 0 20px rgba(0,0,0,0.08);
  }
  
  #avdSidebar.collapsed {
    width: 64px;
  }
  #avdSidebar.collapsed .avd-nav-item-text,
  #avdSidebar.collapsed .avd-nav-badge,
  #avdSidebar.collapsed .avd-nav-label,
  #avdSidebar.collapsed .avd-platform-nav,
  #avdSidebar.collapsed .avd-sidebar-user-trigger > div,
  #avdSidebar.collapsed #avdUserPlan,
  #avdSidebar.collapsed #avdUserChevron {
    display: none;
  }
  #avdSidebar.collapsed .avd-nav-item {
    justify-content: center;
    padding: 10px;
  }
  #avdSidebar.collapsed .avd-nav-item-icon { margin: 0; }
  
  .avd-sidebar-logo-text { display: block; }
  .avd-sidebar-logo-icon  { display: none;  }
  #avdSidebar.collapsed .avd-sidebar-logo-text { display: none; }
  #avdSidebar.collapsed .avd-sidebar-logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 14px 0 10px;
    width: 100%;
  }
  
  .avd-sidebar-scroll {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
  }
  .avd-sidebar-scroll::-webkit-scrollbar { width: 3px; }
  .avd-sidebar-scroll::-webkit-scrollbar-thumb {
    background: rgba(0,0,0,0.10);
    border-radius: 4px;
  }
  
  /* Sidebar collapse toggle */
  .avd-sidebar-toggle {
    position: absolute;
    right: -14px;
    top: 50%;
    transform: translateY(-50%);
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--avd-text-muted);
    font-size: 10px;
    z-index: 300;
    box-shadow: 0 2px 10px rgba(0,0,0,0.15);
    flex-shrink: 0;
  }
  body.light-mode .avd-sidebar-toggle {
    background: #ffffff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.15);
  }
  .avd-sidebar-toggle:hover {
    background: var(--avd-primary);
    color: #fff;
    border-color: var(--avd-primary);
  }
  
  /* ── MAIN ──────────────────────────────────────────────────── */
  #avdMain {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
    min-width: 0;
  }
  
  /* ════════════════════════════════════════════════════════════
     HEADER
  ════════════════════════════════════════════════════════════ */
  #avDriveHeader {
    height: var(--avd-header-h);
    background: var(--avd-header-bg);
    border-bottom: 1px solid var(--avd-border);
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 0 18px;
    flex-shrink: 0;
    position: relative;
    z-index: 100;
  }
  
  .avd-breadcrumb {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
  }
  .avd-breadcrumb-item {
    font-size: 12px;
    font-weight: 700;
    color: var(--avd-text-dim);
    cursor: pointer;
    white-space: nowrap;
  }
  .avd-breadcrumb-item:hover { color: var(--avd-text); }
  .avd-breadcrumb-item.active { color: var(--avd-text); }
  .avd-breadcrumb-sep { font-size: 9px; color: var(--avd-text-dim); }
  
  .avd-header-controls {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: auto;
    flex-shrink: 0;
  }
  
  .avd-header-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 7px 12px;
    background: var(--avd-input-bg);
    border: 1px solid var(--avd-border);
    border-radius: 10px;
    font-family: inherit;
    font-size: 12px;
    font-weight: 600;
    color: var(--avd-text-muted);
    cursor: pointer;
    white-space: nowrap;
  }
  .avd-header-btn:hover {
    background: rgba(0,0,0,0.06);
    color: var(--avd-text);
    border-color: var(--avd-border-hover);
  }
  
  /* Page title in header */
  .avd-header-page-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    font-weight: 800;
    color: var(--avd-text);
  }
  .avd-header-page-title i {
    color: var(--avd-primary);
    font-size: 14px;
  }
  
  /* ════════════════════════════════════════════════════════════
     SIDEBAR NAV
  ════════════════════════════════════════════════════════════ */
  .avd-nav { padding: 4px 8px; }
  .avd-nav-section { margin-bottom: 6px; }
  
  .avd-nav-label {
    padding: 10px 10px 5px;
    font-size: 9px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 1.4px;
    color: var(--avd-text-dim);
  }
  
  .avd-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 10px;
    border-radius: 10px;
    cursor: pointer;
    color: var(--avd-text-muted);
    position: relative;
    margin-bottom: 2px;
  }
  .avd-nav-item:hover {
    background: rgba(0,0,0,0.04);
    color: #1e293b;
  }
  .avd-nav-item.active {
    background: rgba(102,126,234,0.13);
    color: var(--avd-primary);
  }
  .avd-nav-item-icon {
    width: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    flex-shrink: 0;
  }
  .avd-nav-item-text {
    flex: 1;
    font-size: 12px;
    font-weight: 700;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  
  /* ════════════════════════════════════════════════════════════
     PLATFORM NAV
  ════════════════════════════════════════════════════════════ */
  .avd-platform-nav { padding: 0 0 8px; }
  .avd-platform-section { margin-bottom: 1px; }
  
  .avd-platform-folder {
    display: flex;
    align-items: center;
    gap: 9px;
    padding: 8px 10px;
    font-size: 12px;
    font-weight: 700;
    color: var(--avd-text-muted);
    cursor: pointer;
    border-radius: 10px;
    margin: 0 8px;
    background: none;
    border: none;
    width: calc(100% - 16px);
    text-align: left;
  }
  .avd-platform-folder:hover {
    background: rgba(0,0,0,0.04);
    color: #1e293b;
  }
  .avd-platform-folder i:first-child {
    font-size: 13px;
    width: 16px;
    text-align: center;
  }
  .avd-platform-folder .arrow {
    margin-left: auto;
    font-size: 9px;
  }
  .avd-platform-folder.open .arrow { transform: rotate(180deg); }
  
  .avd-platform-submenu { display: none; padding: 2px 0; }
  .avd-platform-submenu.open { display: block; }
  
  .avd-platform-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px 6px 36px;
    font-size: 11px;
    font-weight: 500;
    color: var(--avd-text-dim);
    text-decoration: none;
    border-radius: 8px;
    margin: 0 8px;
  }
  .avd-platform-link:hover {
    background: rgba(0,0,0,0.04);
    color: #475569;
  }
  .avd-platform-link.active {
    color: var(--avd-primary);
    background: rgba(102,126,234,0.08);
  }
  .avd-platform-link i {
    font-size: 11px;
    width: 14px;
    text-align: center;
  }
  .avd-platform-divider {
    border: none;
    border-top: 1px solid var(--avd-border);
    margin: 8px 16px;
  }
  
  /* ════════════════════════════════════════════════════════════
     SIDEBAR FOOTER
  ════════════════════════════════════════════════════════════ */
  .avd-sidebar-footer {
    border-top: 1px solid var(--avd-border);
    position: relative;
    flex-shrink: 0;
  }
  
  .avd-sidebar-user-trigger {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 14px;
    cursor: pointer;
  }
  .avd-sidebar-user-trigger:hover { background: rgba(0,0,0,0.04); }
  
  .avd-sidebar-user-dropdown {
    display: none;
    position: absolute;
    bottom: 100%;
    left: 0;
    right: 0;
    background: #ffffff;
    border: 1px solid rgba(0,0,0,0.10);
    border-radius: 14px;
    padding: 8px;
    margin: 0 8px 6px;
    box-shadow: 0 -8px 32px rgba(0,0,0,0.12);
    z-index: 1000;
  }
  .avd-sidebar-user-dropdown.open { display: block; }
  
  .avd-sidebar-dropdown-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-bottom: 1px solid rgba(0,0,0,0.07);
    margin-bottom: 6px;
  }
  .avd-sidebar-dropdown-header img {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    object-fit: cover;
  }
  
  .avd-sidebar-dropdown-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    color: var(--avd-text-muted);
    text-decoration: none;
    font-size: 12px;
    font-weight: 600;
    border-radius: 8px;
  }
  .avd-sidebar-dropdown-link:hover {
    background: rgba(0,0,0,0.04);
    color: #1e293b;
  }
  .avd-sidebar-dropdown-link i { font-size: 13px; width: 16px; text-align: center; }
  
  .avd-sidebar-dropdown-logout {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    color: var(--avd-red);
    font-size: 12px;
    font-weight: 700;
    border-radius: 8px;
    cursor: pointer;
    background: none;
    border: none;
    width: 100%;
    text-align: left;
    margin-top: 4px;
    border-top: 1px solid rgba(0,0,0,0.06);
  }
  .avd-sidebar-dropdown-logout:hover { background: rgba(239,68,68,0.08); }
  
  /* ── Mobile close btn ─────────────────────────────── */
  .avd-mobile-close-btn {
    display: none;
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: rgba(0,0,0,0.06);
    border: 1px solid var(--avd-border);
    color: var(--avd-text-muted);
    font-size: 14px;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    z-index: 10;
  }
  @media (max-width: 768px) {
    .avd-mobile-close-btn { display: flex; }
  }
  
  /* ════════════════════════════════════════════════════════════
     CONTENT AREA
  ════════════════════════════════════════════════════════════ */
  #avDriveContent {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 24px 28px;
  }
  #avDriveContent::-webkit-scrollbar { width: 5px; }
  #avDriveContent::-webkit-scrollbar-thumb {
    background: rgba(0,0,0,0.12);
    border-radius: 4px;
  }
  
  /* ════════════════════════════════════════════════════════════
     RESOURCE CONTAINER & HEADER
  ════════════════════════════════════════════════════════════ */
  .resource-container {
    max-width: 920px;
    margin: 0 auto;
  }
  
  .resource-header {
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-xl);
    padding: 32px 36px;
    margin-bottom: 20px;
    box-shadow: var(--avd-shadow);
  }
  
  .resource-breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    color: var(--avd-text-dim);
    margin-bottom: 16px;
  }
  .resource-breadcrumb a {
    color: var(--avd-primary);
    font-weight: 600;
    text-decoration: none;
  }
  .resource-breadcrumb a:hover { text-decoration: underline; }
  .resource-breadcrumb i { font-size: 9px; color: var(--avd-text-dim); }
  
  .resource-title {
    font-size: 28px;
    font-weight: 900;
    color: var(--avd-text);
    margin-bottom: 12px;
    line-height: 1.3;
  }
  
  .resource-subtitle {
    font-size: 14px;
    color: var(--avd-text-muted);
    line-height: 1.7;
    margin-bottom: 20px;
  }
  
  .resource-meta {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
  }
  .meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--avd-text-muted);
    font-weight: 600;
  }
  .meta-item i { color: var(--avd-primary); font-size: 12px; }
  
  .difficulty-badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.8px;
  }
  .difficulty-badge.expert {
    background: rgba(239,68,68,0.10);
    color: var(--avd-red);
    border: 1px solid rgba(239,68,68,0.20);
  }
  .difficulty-badge.intermediate {
    background: rgba(245,158,11,0.10);
    color: var(--avd-amber);
    border: 1px solid rgba(245,158,11,0.20);
  }
  .difficulty-badge.beginner {
    background: rgba(16,185,129,0.10);
    color: var(--avd-green);
    border: 1px solid rgba(16,185,129,0.20);
  }
  
  /* ════════════════════════════════════════════════════════════
     TABLE OF CONTENTS
  ════════════════════════════════════════════════════════════ */
  .table-of-contents {
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    padding: 24px 28px;
    margin-bottom: 20px;
    box-shadow: var(--avd-shadow);
  }
  
  .toc-title {
    font-size: 14px;
    font-weight: 800;
    color: var(--avd-text);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .toc-title i { color: var(--avd-primary); }
  
  .toc-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 6px;
  }
  .toc-list li {
    counter-increment: toc-counter;
  }
  .toc-list a {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 600;
    color: var(--avd-primary);
    text-decoration: none;
    padding: 6px 10px;
    border-radius: 8px;
  }
  .toc-list a::before {
    content: counter(toc-counter, decimal-leading-zero);
    font-size: 10px;
    font-weight: 800;
    color: var(--avd-text-dim);
    min-width: 20px;
  }
  .toc-list a:hover {
    background: rgba(102,126,234,0.08);
  }
  
  /* ════════════════════════════════════════════════════════════
     CONTENT SECTIONS
  ════════════════════════════════════════════════════════════ */
  .content-section {
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    padding: 28px 32px;
    margin-bottom: 20px;
    box-shadow: var(--avd-shadow);
  }
  
  .section-header {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 900;
    color: var(--avd-text);
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--avd-border);
  }
  .section-header i { color: var(--avd-primary); }
  
  .subsection-header {
    font-size: 15px;
    font-weight: 800;
    color: var(--avd-text);
    margin: 24px 0 14px;
    display: flex;
    align-items: center;
    gap: 8px;
  }
  .subsection-header::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 16px;
    background: linear-gradient(135deg, var(--avd-primary), var(--avd-primary-dark));
    border-radius: 2px;
  }
  
  .content-text {
    font-size: 14px;
    line-height: 1.8;
    color: var(--avd-text-muted);
    margin-bottom: 20px;
  }
  .content-text strong { color: var(--avd-text); font-weight: 700; }
  
  /* ════════════════════════════════════════════════════════════
     INFO / WARNING / SUCCESS BOXES
  ════════════════════════════════════════════════════════════ */
  .info-box,
  .warning-box,
  .success-box {
    border-radius: var(--avd-radius-lg);
    padding: 20px 24px;
    margin: 20px 0;
    border: 1px solid;
  }
  
  .info-box {
    background: rgba(102,126,234,0.06);
    border-color: rgba(102,126,234,0.20);
  }
  .warning-box {
    background: rgba(245,158,11,0.06);
    border-color: rgba(245,158,11,0.20);
  }
  .success-box {
    background: rgba(16,185,129,0.06);
    border-color: rgba(16,185,129,0.20);
  }
  
  .box-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 12px;
  }
  .info-box    .box-header { color: var(--avd-primary); }
  .warning-box .box-header { color: var(--avd-amber); }
  .success-box .box-header { color: var(--avd-green); }
  .box-header i { font-size: 14px; }
  
  .box-content {
    font-size: 13px;
    line-height: 1.7;
    color: var(--avd-text-muted);
  }
  .box-content strong { color: var(--avd-text); font-weight: 700; }
  .box-content p { margin-bottom: 10px; }
  .box-content p:last-child { margin-bottom: 0; }
  
  /* ════════════════════════════════════════════════════════════
     STYLED LIST
  ════════════════════════════════════════════════════════════ */
  .styled-list {
    list-style: none;
    padding: 0;
    margin: 10px 0;
  }
  .styled-list li {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 13px;
    color: var(--avd-text-muted);
    padding: 5px 0;
    line-height: 1.6;
  }
  .styled-list li::before {
    content: '→';
    color: var(--avd-primary);
    font-weight: 800;
    flex-shrink: 0;
    margin-top: 1px;
  }
  .styled-list li strong { color: var(--avd-text); }
  
  /* ════════════════════════════════════════════════════════════
     FORMULA BLOCK
  ════════════════════════════════════════════════════════════ */
  .formula-block {
    background: linear-gradient(135deg, rgba(102,126,234,0.08), rgba(118,75,162,0.06));
    border: 1px solid rgba(102,126,234,0.20);
    border-radius: var(--avd-radius-lg);
    padding: 24px;
    margin: 20px 0;
  }
  
  .formula-title {
    font-size: 11px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--avd-primary);
    margin-bottom: 14px;
  }
  
  .formula-content {
    font-family: 'Courier New', 'Fira Code', monospace;
    font-size: 14px;
    font-weight: 600;
    color: var(--avd-text);
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius);
    padding: 16px 20px;
    line-height: 1.8;
  }
  
  .formula-legend {
    margin-top: 16px;
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 6px 12px;
    font-size: 12px;
  }
  .formula-legend dt {
    font-weight: 700;
    color: var(--avd-primary);
  }
  .formula-legend dd {
    color: var(--avd-text-muted);
    margin: 0;
  }
  
  /* ════════════════════════════════════════════════════════════
     DATA TABLES
  ════════════════════════════════════════════════════════════ */
  .data-table-wrapper {
    overflow-x: auto;
    border-radius: var(--avd-radius-lg);
    border: 1px solid var(--avd-border);
    margin: 16px 0;
  }
  
  .data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
  }
  
  .data-table thead tr {
    background: rgba(102,126,234,0.08);
  }
  
  .data-table th {
    padding: 12px 16px;
    font-size: 10px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--avd-primary);
    text-align: left;
    border-bottom: 1px solid var(--avd-border);
    white-space: nowrap;
  }
  
  .data-table td {
    padding: 11px 16px;
    font-size: 12px;
    color: var(--avd-text-muted);
    border-bottom: 1px solid var(--avd-border);
    line-height: 1.5;
  }
  
  .data-table tbody tr:last-child td {
    border-bottom: none;
  }
  
  .data-table tbody tr:hover {
    background: rgba(102,126,234,0.04);
  }
  
  .data-table td strong { color: var(--avd-text); font-weight: 700; }
  
  /* ════════════════════════════════════════════════════════════
     EXAMPLE CARD
  ════════════════════════════════════════════════════════════ */
  .example-card {
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    overflow: hidden;
    margin: 20px 0;
  }
  
  .example-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 20px;
    background: rgba(102,126,234,0.08);
    border-bottom: 1px solid var(--avd-border);
    font-size: 13px;
    font-weight: 800;
    color: var(--avd-primary);
  }
  
  .example-content {
    padding: 20px;
    background: var(--avd-card);
    font-size: 13px;
    color: var(--avd-text-muted);
    line-height: 1.7;
  }
  .example-content p { margin-bottom: 10px; }
  .example-content strong { color: var(--avd-text); }
  
  /* ════════════════════════════════════════════════════════════
     CODE BLOCKS
  ════════════════════════════════════════════════════════════ */
  .code-block {
    background: #1e293b;
    border-radius: var(--avd-radius-lg);
    overflow: hidden;
    margin: 16px 0;
    box-shadow: 0 4px 20px rgba(0,0,0,0.10);
  }
  
  .code-header {
    background: #0f172a;
    padding: 10px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255,255,255,0.08);
  }
  
  .code-lang {
    color: #94a3b8;
    font-size: 10px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 1px;
  }
  
  .copy-code-btn {
    background: rgba(59,130,246,0.10);
    color: #3b82f6;
    border: 1px solid rgba(59,130,246,0.25);
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 700;
    cursor: pointer;
  }
  .copy-code-btn:hover {
    background: rgba(59,130,246,0.20);
    border-color: rgba(59,130,246,0.40);
  }
  
  .code-content {
    background: #1e293b;
    color: #e2e8f0;
    padding: 20px;
    overflow-x: auto;
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 12px;
    line-height: 1.7;
    white-space: pre;
    tab-size: 4;
    margin: 0;
  }
  
  .code-content::-webkit-scrollbar { height: 6px; }
  .code-content::-webkit-scrollbar-track { background: rgba(15,23,42,0.5); }
  .code-content::-webkit-scrollbar-thumb { background: rgba(59,130,246,0.25); border-radius: 4px; }
  
  /* ════════════════════════════════════════════════════════════
     PAGE NAVIGATION
  ════════════════════════════════════════════════════════════ */
  .page-navigation {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-top: 8px;
    padding-top: 8px;
  }
  
  .nav-button {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    font-size: 13px;
    font-weight: 700;
    color: var(--avd-text-muted);
    text-decoration: none;
    box-shadow: var(--avd-shadow);
  }
  .nav-button:hover {
    border-color: var(--avd-primary);
    color: var(--avd-primary);
    background: rgba(102,126,234,0.06);
  }
  .nav-button.next { margin-left: auto; }
  
  /* ════════════════════════════════════════════════════════════
     ML VISUALIZATIONS
  ════════════════════════════════════════════════════════════ */
  .neural-network-canvas {
    width: 100%;
    height: 420px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: var(--avd-radius-lg);
    box-shadow: 0 4px 20px rgba(102,126,234,0.25);
    margin: 20px 0;
    position: relative;
    overflow: hidden;
  }
  .neural-network-canvas canvas {
    width: 100%;
    height: 100%;
  }
  
  .architecture-diagram {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    border-radius: var(--avd-radius-lg);
    padding: 24px;
    margin: 20px 0;
    box-shadow: 0 4px 20px rgba(240,147,251,0.25);
  }
  .architecture-diagram svg {
    width: 100%;
    height: auto;
  }
  
  .ml-pipeline-diagram {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    border-radius: var(--avd-radius-lg);
    padding: 24px;
    margin: 20px 0;
    box-shadow: 0 4px 20px rgba(79,172,254,0.25);
  }
  
  /* Performance chart container */
  .performance-chart-container {
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    padding: 24px;
    margin: 20px 0;
    box-shadow: var(--avd-shadow);
  }
  
  .chart-title {
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--avd-primary);
    display: flex;
    align-items: center;
    gap: 8px;
  }
  
  /* Ensemble architecture */
  .ensemble-architecture {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin: 20px 0;
  }
  
  .model-card {
    background: var(--avd-card);
    border: 1px solid var(--avd-border);
    border-radius: var(--avd-radius-lg);
    padding: 20px;
    text-align: center;
    box-shadow: var(--avd-shadow);
  }
  
  .model-icon { font-size: 2.5rem; margin-bottom: 10px; }
  .model-name {
    font-size: 13px;
    font-weight: 700;
    color: var(--avd-text);
    margin-bottom: 6px;
  }
  .model-accuracy {
    font-size: 1.8rem;
    font-weight: 900;
    color: var(--avd-green);
  }
  
  /* Feature importance */
  .feature-importance-viz { margin: 16px 0; }
  
  .feature-bar {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
  }
  .feature-label {
    width: 140px;
    font-size: 12px;
    font-weight: 600;
    color: var(--avd-text-muted);
    flex-shrink: 0;
  }
  .feature-bar-fill {
    flex: 1;
    height: 28px;
    background: linear-gradient(90deg, var(--avd-primary), var(--avd-primary-dark));
    border-radius: 6px;
    position: relative;
    box-shadow: 0 2px 8px rgba(102,126,234,0.20);
  }
  .feature-value {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    color: white;
    font-weight: 700;
    font-size: 11px;
  }
  
  /* Confusion matrix */
  .confusion-matrix {
    display: grid;
    grid-template-columns: auto repeat(2, 1fr);
    gap: 1px;
    background: var(--avd-border);
    border-radius: var(--avd-radius-lg);
    overflow: hidden;
    margin: 16px auto;
    max-width: 420px;
  }
  .confusion-cell {
    background: var(--avd-card);
    padding: 16px;
    text-align: center;
    font-weight: 700;
    color: var(--avd-text-muted);
    font-size: 12px;
  }
  .confusion-header {
    background: linear-gradient(135deg, var(--avd-primary), var(--avd-primary-dark));
    color: white;
    font-weight: 800;
    font-size: 11px;
  }
  .confusion-value {
    font-size: 1.6rem;
    font-weight: 900;
    color: var(--avd-green);
  }
  .confusion-label {
    font-size: 10px;
    color: var(--avd-text-dim);
    margin-top: 4px;
  }
  
  /* ════════════════════════════════════════════════════════════
     SCROLLBARS GLOBAL
  ════════════════════════════════════════════════════════════ */
  * { scrollbar-width: thin; scrollbar-color: rgba(0,0,0,0.12) transparent; }
  *::-webkit-scrollbar { width: 4px; height: 4px; }
  *::-webkit-scrollbar-thumb { background: rgba(0,0,0,0.14); border-radius: 4px; }
  
  /* ════════════════════════════════════════════════════════════
     BUTTONS
  ════════════════════════════════════════════════════════════ */
  .avd-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 10px;
    font-family: inherit;
    font-size: 12px;
    font-weight: 700;
    cursor: pointer;
    border: 1px solid transparent;
    text-decoration: none;
  }
  .avd-btn-secondary {
    background: var(--avd-input-bg);
    border-color: var(--avd-border);
    color: var(--avd-text-muted);
  }
  .avd-btn-secondary:hover {
    background: rgba(0,0,0,0.06);
    color: var(--avd-text);
  }
  
  /* ════════════════════════════════════════════════════════════
     RESPONSIVE — TABLET (≤ 1024px)
  ════════════════════════════════════════════════════════════ */
  @media (max-width: 1024px) {
    #avDriveContent { padding: 18px 20px; }
    .content-section { padding: 22px 24px; }
    .resource-header { padding: 24px 28px; }
    .ensemble-architecture { grid-template-columns: repeat(2, 1fr); }
    .toc-list { grid-template-columns: 1fr; }
  }
  
  /* ════════════════════════════════════════════════════════════
     RESPONSIVE — MOBILE (≤ 768px)
  ════════════════════════════════════════════════════════════ */
  @media (max-width: 768px) {
    #avdSidebar {
      position: fixed;
      left: 0; top: 0; bottom: 0;
      z-index: 1000;
      transform: translateX(-100%);
      overflow-y: auto;
      overflow-x: hidden;
    }
    #avdSidebar.mobile-open {
      transform: translateX(0);
      box-shadow: 4px 0 40px rgba(0,0,0,0.20);
    }
    .avd-sidebar-toggle { display: none !important; }
    #avdMobileMenuBtn { display: flex !important; }
    #avDriveContent { padding: 14px 16px; }
    .content-section { padding: 18px 20px; }
    .resource-header { padding: 20px 22px; }
    .resource-title { font-size: 22px; }
    .ensemble-architecture { grid-template-columns: 1fr; }
    .neural-network-canvas { height: 320px; }
    .feature-label { width: 110px; font-size: 11px; }
    .confusion-matrix { max-width: 100%; }
    .page-navigation { flex-direction: column; }
    .nav-button.next { margin-left: 0; }
    .avd-breadcrumb { display: none; }
  }
  
  /* ════════════════════════════════════════════════════════════
     RESPONSIVE — SMALL (≤ 480px)
  ════════════════════════════════════════════════════════════ */
  @media (max-width: 480px) {
    :root { --avd-header-h: 52px; }
    #avDriveHeader { padding: 0 10px; gap: 6px; }
    .avd-header-btn span { display: none; }
    .content-section { padding: 14px 16px; }
    .resource-header { padding: 16px 18px; }
    .resource-title { font-size: 18px; }
    .neural-network-canvas { height: 260px; }
    .ensemble-architecture { gap: 10px; }
    .feature-bar { flex-direction: column; align-items: flex-start; gap: 6px; }
    .feature-label { width: 100%; }
    .feature-bar-fill { width: 100%; }
  }