/* Topic Content Page Styles */

/* Thin Fixed Navigation Bar */
.lesson-nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 50px;
  background: rgba(var(--bs-body-bg-rgb), 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  z-index: 1030;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.lesson-nav-bar-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 1rem;
}

.nav-bar-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border: none;
  background: transparent;
  color: var(--bs-body-color);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 8px;
  transition: all 0.3s ease;
  cursor: pointer;
  white-space: nowrap;
}

.nav-bar-item:hover:not(.disabled):not(.nav-bar-title) {
  background: rgba(var(--bs-primary-rgb), 0.1);
  color: var(--bs-primary);
  transform: translateY(-1px);
}

.nav-bar-item i {
  font-size: 1rem;
}

.nav-bar-item.disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.nav-bar-back {
  color: var(--bs-primary);
}

.nav-bar-back:hover {
  background: rgba(var(--bs-primary-rgb), 0.15);
}

.nav-bar-title {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  justify-content: center;
  font-weight: 600;
  color: var(--bs-body-color);
}

.nav-bar-module {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  color: white;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 700;
}

.nav-bar-name {
  font-size: 0.95rem;
}

.nav-bar-complete {
  padding: 0.5rem 1rem;
  height: 40px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: rgba(var(--bs-secondary-rgb), 0.1);
  border: 2px solid rgba(var(--bs-secondary-rgb), 0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.nav-bar-complete .complete-text {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--bs-secondary);
  transition: all 0.3s ease;
}

.nav-bar-complete i {
  font-size: 1.1rem;
  color: var(--bs-secondary);
  transition: all 0.3s ease;
}

.nav-bar-complete:hover {
  background: rgba(var(--bs-success-rgb), 0.15);
  border-color: var(--bs-success);
  transform: translateY(-2px);
}

.nav-bar-complete:hover i,
.nav-bar-complete:hover .complete-text {
  color: var(--bs-success);
}

.nav-bar-complete.completed {
  background: linear-gradient(135deg, rgba(var(--bs-success-rgb), 0.2), rgba(var(--bs-success-rgb), 0.3));
  border-color: var(--bs-success);
  animation: completePulse 2s ease-in-out infinite;
}

.nav-bar-complete.completed i,
.nav-bar-complete.completed .complete-text {
  color: var(--bs-success);
  font-weight: 700;
}

.nav-bar-complete.completed::after {
  content: '✓';
  position: absolute;
  top: -5px;
  right: -5px;
  width: 20px;
  height: 20px;
  background: var(--bs-success);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: bold;
  box-shadow: 0 2px 8px rgba(var(--bs-success-rgb), 0.4);
}

@keyframes completePulse {
  0%, 100% { 
    box-shadow: 0 0 0 0 rgba(var(--bs-success-rgb), 0.4);
  }
  50% { 
    box-shadow: 0 0 0 8px rgba(var(--bs-success-rgb), 0);
  }
}

/* Responsive Nav Bar */
@media (max-width: 768px) {
  .nav-bar-name {
    display: none;
  }
  
  .nav-bar-item span {
    display: none;
  }
  
  .nav-bar-item {
    padding: 0.5rem;
    min-width: 40px;
    justify-content: center;
  }
  
  .nav-bar-module {
    width: 32px;
    height: 32px;
    font-size: 0.75rem;
  }
  
  /* Keep complete button visible on mobile */
  .nav-bar-complete .complete-text {
    display: none;
  }
  
  .nav-bar-complete {
    width: 40px;
    height: 40px;
    padding: 0.5rem;
    border-radius: 50%;
  }
}

/* Full Width Content Wrapper */
.content-wrapper {
  max-width: 1400px;
  margin: 0 auto;
}

.content-body-fullwidth {
  width: 100%;
}

/* Floating TOC Sidebar */
.floating-toc {
  position: fixed;
  right: 20px;
  top: 120px;
  z-index: 999;
}

.toc-toggle {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  border: none;
  color: white;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.toc-toggle:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.toc-content {
  position: absolute;
  right: 0;
  top: 60px;
  width: 280px;
  background: rgba(var(--bs-body-bg-rgb), 0.95);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
  opacity: 0;
  visibility: hidden;
  transform: translateX(20px);
  transition: all 0.3s ease;
}

.toc-content.active {
  opacity: 1;
  visibility: visible;
  transform: translateX(0);
}

.toc-content .toc-title {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 1rem;
  color: var(--bs-primary);
}

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

.toc-content .toc-list li {
  margin-bottom: 0.5rem;
}

.toc-content .toc-link {
  display: flex;
  align-items: center;
  color: var(--bs-body-color);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.5rem;
  border-radius: 8px;
  transition: all 0.2s ease;
}

.toc-content .toc-link:hover {
  background: rgba(var(--bs-primary-rgb), 0.1);
  color: var(--bs-primary);
  transform: translateX(4px);
}

.toc-content .toc-link.active {
  background: rgba(var(--bs-primary-rgb), 0.15);
  color: var(--bs-primary);
  font-weight: 600;
}

.toc-content .toc-link i {
  font-size: 0.7rem;
}

/* Bottom Section - Resources & Progress */
.bottom-section {
  border-top: 2px solid rgba(var(--bs-border-color-rgb), 0.2);
  padding-top: 4rem;
}

.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 1.5rem;
}

.resource-card {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.5rem;
  background: rgba(var(--bs-body-bg-rgb), 0.5);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 16px;
  text-decoration: none;
  color: var(--bs-body-color);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.resource-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--bs-primary), var(--bs-info));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.resource-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
  border-color: rgba(var(--bs-primary-rgb), 0.3);
}

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

.resource-card-icon {
  width: 60px;
  height: 60px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: white;
  flex-shrink: 0;
}

.resource-card-content {
  flex: 1;
}

.resource-card-content h5 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--bs-body-color);
}

.resource-card-content p {
  font-size: 0.9rem;
  color: var(--bs-secondary-color);
  margin-bottom: 0.75rem;
}

.resource-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.resource-meta .badge {
  font-size: 0.75rem;
  padding: 0.35rem 0.6rem;
  font-weight: 600;
}

.resource-link-icon {
  color: var(--bs-primary);
  font-size: 1.2rem;
  opacity: 0.5;
  transition: all 0.3s ease;
}

.resource-card:hover .resource-link-icon {
  opacity: 1;
  transform: translateX(4px);
}

.progress-tracker {
  position: sticky;
  top: 120px;
  padding: 2rem;
  background: rgba(var(--bs-success-rgb), 0.05);
  border: 2px solid rgba(var(--bs-success-rgb), 0.2);
  border-radius: 20px;
  text-align: center;
}

.progress-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.progress-header i {
  font-size: 2rem;
}

.progress-header h4 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0;
}

.progress-tracker p {
  margin-bottom: 1.5rem;
}

.progress-stats {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
}

.progress-stats .stat {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: var(--bs-secondary-color);
}

.progress-stats .stat i {
  font-size: 1.1rem;
}

/* Mobile Responsive for New Layout */
@media (max-width: 1200px) {
  .floating-toc {
    display: none;
  }
  
  .resources-grid {
    grid-template-columns: 1fr;
  }
  
  .progress-tracker {
    position: relative;
    top: 0;
  }
}

@media (max-width: 768px) {
  .content-wrapper {
    padding: 0 1rem;
  }
  
  .resource-card {
    flex-direction: column;
    text-align: center;
  }
  
  .resource-card-icon {
    width: 50px;
    height: 50px;
    font-size: 1.2rem;
  }
  
  .resource-card-content h5 {
    font-size: 1rem;
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Hero Section */
.content-hero {
  background: linear-gradient(135deg, rgba(99,102,241,.08) 0%, rgba(139,92,246,.08) 100%);
  padding: 120px 0 60px;
}

/* Content Body */
.content-body {
  font-size: 1.1rem;
  line-height: 1.8;
}

.content-body h2 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-top: 3rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--bs-primary);
  display: inline-block;
}

.content-body h3 {
  font-size: 1.35rem;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 1rem;
  color: var(--bs-primary);
}

.content-body h4 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
}

.content-body p {
  margin-bottom: 1.25rem;
  color: var(--bs-secondary-color);
}

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

.content-body li {
  margin-bottom: 0.5rem;
}

/* Definition Box */
.definition-box {
  background: linear-gradient(135deg, rgba(99,102,241,.1) 0%, rgba(139,92,246,.05) 100%);
  border-left: 4px solid var(--bs-primary);
  border-radius: 0 12px 12px 0;
  padding: 1.5rem;
  margin: 2rem 0;
}

.definition-box p {
  margin-bottom: 0;
  font-size: 1.15rem;
  font-style: italic;
}

/* Example Box */
.example-box {
  background: rgba(25, 135, 84, 0.1);
  border-left: 4px solid var(--bs-success);
  border-radius: 0 12px 12px 0;
  padding: 1.5rem;
  margin: 2rem 0;
}

.example-box h4 {
  color: var(--bs-success);
  margin-top: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Warning/Note Box */
.note-box {
  background: rgba(255, 193, 7, 0.1);
  border-left: 4px solid var(--bs-warning);
  border-radius: 0 12px 12px 0;
  padding: 1.5rem;
  margin: 2rem 0;
}

.note-box h4 {
  color: var(--bs-warning);
  margin-top: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Comparison Table */
.comparison-table {
  margin: 2rem 0;
  overflow-x: auto;
}

.comparison-table table {
  width: 100%;
  border-collapse: collapse;
}

.comparison-table th {
  background: var(--bs-primary);
  color: white;
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

.comparison-table td {
  padding: 1rem;
  border-bottom: 1px solid var(--bs-border-color);
  vertical-align: top;
}

.comparison-table tr:hover td {
  background: rgba(99,102,241,.05);
}

/* Code Blocks */
pre[class*="language-"] {
  border-radius: 12px;
  margin: 1.5rem 0;
}

code {
  font-family: 'JetBrains Mono', monospace;
}

/* Venn Diagram */
.diagram-container {
  margin: 2rem 0;
  text-align: center;
}

.venn-diagram {
  position: relative;
  height: 300px;
  margin: 2rem auto;
  max-width: 500px;
}

.venn-circle {
  position: absolute;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.9rem;
  text-align: center;
  opacity: 0.7;
  transition: opacity 0.3s;
}

.venn-circle:hover {
  opacity: 1;
}

.venn-math {
  background: rgba(239, 68, 68, 0.3);
  top: 0;
  left: 50%;
  transform: translateX(-50%);
}

.venn-cs {
  background: rgba(59, 130, 246, 0.3);
  bottom: 0;
  left: 0;
}

.venn-domain {
  background: rgba(34, 197, 94, 0.3);
  bottom: 0;
  right: 0;
}

.venn-center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--bs-primary);
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

figcaption {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--bs-secondary-color);
  font-style: italic;
}

/* Career Cards */
.career-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.career-card {
  background: var(--bs-body-bg);
  border: 1px solid var(--bs-border-color);
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.3s;
}

.career-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(99,102,241,0.2);
  border-color: var(--bs-primary);
}

.career-card h4 {
  color: var(--bs-primary);
  margin-bottom: 0.5rem;
}

.career-card .salary {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--bs-success);
  margin: 0.5rem 0;
}

/* Quiz Styles */
.quiz-container {
  background: var(--bs-body-bg);
  border: 2px solid var(--bs-border-color);
  border-radius: 16px;
  padding: 2rem;
  margin: 3rem 0;
}

.quiz-question {
  background: rgba(99,102,241,0.03);
  border: 1px solid var(--bs-border-color);
  border-left: 4px solid var(--bs-border-color);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  transition: all 0.3s ease;
}

.quiz-question p {
  font-weight: 600;
  font-size: 1.05rem;
  margin-bottom: 1rem;
  color: var(--bs-body-color);
}

.quiz-options {
  margin: 1rem 0;
}

.quiz-options label {
  display: block;
  padding: 1rem 1.25rem;
  margin-bottom: 0.75rem;
  border: 2px solid var(--bs-border-color);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
  background: var(--bs-body-bg);
  font-weight: 500;
}

.quiz-options label:hover {
  border-color: var(--bs-primary);
  background: rgba(99,102,241,.08);
  transform: translateX(5px);
}

.quiz-options input[type="radio"] {
  margin-right: 0.75rem;
  cursor: pointer;
  width: 18px;
  height: 18px;
  accent-color: var(--bs-primary);
}

.quiz-options input[type="radio"]:disabled {
  cursor: not-allowed;
}

.quiz-options label:has(input:disabled) {
  cursor: not-allowed;
  opacity: 0.9;
}

.quiz-explanation {
  animation: fadeIn 0.3s ease-in;
  font-size: 0.95rem;
  line-height: 1.6;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Button Improvements */
.btn-primary {
  transition: all 0.3s ease;
}

.btn-primary:not(:disabled):hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99,102,241,0.4);
}

.btn-primary:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

/* Reading Time */
.reading-time {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--bs-secondary-color);
}

/* Progress Indicator */
.lesson-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: rgba(99,102,241,0.1);
  z-index: 9999;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--bs-primary), #8b5cf6);
  transition: width 0.1s;
}

/* TOC Sidebar */
.toc-sidebar {
  position: sticky;
  top: 100px;
}

.toc-title {
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--bs-body-color);
}

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

.toc-list li {
  margin-bottom: 0.5rem;
}

.toc-list a {
  color: var(--bs-secondary-color);
  text-decoration: none;
  padding: 0.5rem 0;
  display: block;
  border-left: 2px solid transparent;
  padding-left: 1rem;
  transition: all 0.2s;
}

.toc-list a:hover, .toc-list a.active {
  color: var(--bs-primary);
  border-left-color: var(--bs-primary);
}

/* Lesson Navigation */
.lesson-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin: 3rem 0;
}

.lesson-nav a {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
  background: var(--bs-body-bg);
  border: 1px solid var(--bs-border-color);
  border-radius: 12px;
  text-decoration: none;
  color: var(--bs-body-color);
  transition: all 0.3s;
}

.lesson-nav a:hover {
  border-color: var(--bs-primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(99,102,241,0.2);
}

.lesson-nav a.prev {
  justify-content: flex-start;
}

.lesson-nav a.next {
  justify-content: flex-end;
  text-align: right;
}

.lesson-nav .label {
  font-size: 0.85rem;
  color: var(--bs-secondary-color);
  display: block;
}

.lesson-nav .title {
  font-weight: 600;
  display: block;
}

/* Scroll to Top Button */
.scroll-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(99,102,241,0.3);
  z-index: 1000;
  transition: all 0.3s;
}

.scroll-top-btn.show {
  display: flex;
}

.scroll-top-btn:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 20px rgba(99,102,241,0.4);
}

/* Modern Section Styling */
.section-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 2rem;
}

.section-number {
  font-size: 3.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  opacity: 0.15;
  font-family: 'Inter', sans-serif;
}

.section-header h2 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
}

.subsection-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
  color: var(--bs-body-color);
}

.lead-text {
  font-size: 1.15rem;
  color: var(--bs-secondary);
  line-height: 1.8;
  margin-bottom: 2rem;
}

/* Modern Definition Box */
.definition-box-modern {
  background: linear-gradient(135deg, rgba(99,102,241,.08) 0%, rgba(139,92,246,.05) 100%);
  border-radius: 16px;
  padding: 2.5rem;
  margin: 2rem 0;
  position: relative;
  border: 1px solid rgba(99,102,241,.15);
}

.definition-quote-icon {
  position: absolute;
  top: -20px;
  left: 30px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  box-shadow: 0 4px 15px rgba(99,102,241,.3);
}

.definition-content {
  margin-top: 1rem;
}

.definition-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--bs-primary);
  margin-bottom: 1rem;
}

.definition-text {
  font-size: 1.2rem;
  line-height: 1.8;
  margin-bottom: 1rem;
  color: var(--bs-body-color);
}

.definition-subtext {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--bs-secondary);
  margin-bottom: 0;
}

/* Info Callout */
.info-callout {
  display: flex;
  align-items: flex-start;
  gap: 15px;
  background: rgba(13,110,253,.1);
  border-left: 4px solid var(--bs-info);
  border-radius: 0 12px 12px 0;
  padding: 1.25rem 1.5rem;
  margin: 2rem 0;
}

.info-callout i {
  font-size: 1.5rem;
  color: var(--bs-info);
  flex-shrink: 0;
  margin-top: 2px;
}

.info-callout strong {
  color: var(--bs-info);
}

/* Pillar Cards - Three Pillars */
.pillar-card {
  background: var(--bs-body-bg);
  border: 2px solid var(--bs-border-color);
  border-radius: 16px;
  overflow: hidden;
  transition: all .3s cubic-bezier(0.4, 0, 0.2, 1);
  height: 100%;
}

.pillar-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 12px 40px rgba(99,102,241,.15);
  border-color: var(--bs-primary);
}

.pillar-card-header {
  padding: 1.5rem;
  text-align: center;
  background: rgba(99,102,241,.03);
  border-bottom: 2px solid var(--bs-border-color);
}

.pillar-icon {
  width: 70px;
  height: 70px;
  margin: 0 auto 1rem;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: white;
}

.bg-gradient-danger {
  background: linear-gradient(135deg, #dc3545, #e85d6a);
}

.bg-gradient-primary {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
}

.bg-gradient-success {
  background: linear-gradient(135deg, #198754, #20c997);
}

.bg-gradient-warning {
  background: linear-gradient(135deg, #ffc107, #fd7e14);
}

.bg-gradient-info {
  background: linear-gradient(135deg, #0dcaf0, #0d6efd);
}

.bg-gradient-secondary {
  background: linear-gradient(135deg, #6c757d, #adb5bd);
}

.pillar-card-header h4 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0;
}

.pillar-card-body {
  padding: 1.5rem;
}

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

.pillar-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid rgba(99,102,241,.08);
  transition: all .2s;
}

.pillar-list li:last-child {
  border-bottom: none;
}

.pillar-list li:hover {
  padding-left: 8px;
  color: var(--bs-primary);
}

.pillar-list i {
  color: var(--bs-primary);
  font-size: 0.75rem;
  flex-shrink: 0;
}

/* Lifecycle Grid - Modern 2x3 Grid */
.lifecycle-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.lifecycle-card {
  background: var(--bs-body-bg);
  border: 2px solid var(--bs-border-color);
  border-radius: 16px;
  padding: 2rem;
  position: relative;
  transition: all .3s cubic-bezier(0.4, 0, 0.2, 1);
}

.lifecycle-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 35px rgba(99,102,241,.12);
  border-color: var(--bs-primary);
}

.lifecycle-number {
  position: absolute;
  top: -15px;
  left: 20px;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(99,102,241,.3);
}

.lifecycle-icon-wrapper {
  width: 60px;
  height: 60px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  color: white;
  font-size: 1.75rem;
}

.lifecycle-card h4 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.lifecycle-card p {
  color: var(--bs-secondary);
  margin-bottom: 1rem;
  line-height: 1.6;
}

.lifecycle-highlight {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,193,7,.15);
  border: 1px solid rgba(255,193,7,.3);
  border-radius: 8px;
  padding: 8px 12px;
  margin-bottom: 1rem;
  font-size: 0.9rem;
}

.lifecycle-highlight i {
  color: var(--bs-warning);
}

.lifecycle-highlight strong {
  color: var(--bs-warning);
  font-size: 1.1rem;
}

.lifecycle-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tech-badge {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(99,102,241,.1);
  border: 1px solid rgba(99,102,241,.2);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--bs-primary);
}

/* Responsive */
@media (max-width: 991px) {
  .toc-sidebar {
    position: static;
    margin-bottom: 2rem;
  }
  
  .lesson-nav {
    grid-template-columns: 1fr;
  }
  
  .venn-diagram {
    height: 250px;
  }
  
  .venn-circle {
    width: 150px;
    height: 150px;
    font-size: 0.8rem;
  }
  
  .section-number {
    font-size: 2.5rem;
  }
  
  .lifecycle-grid {
    grid-template-columns: 1fr;
  }
  
  .careers-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== CAREER CARDS - MODERN DESIGN ===== */
.careers-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-top: 2rem;
}

.career-card-modern {
  position: relative;
  background: rgba(var(--bs-body-bg-rgb), 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 20px;
  padding: 2rem;
  transition: all 0.4s ease;
  overflow: hidden;
}

.career-card-modern::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--bs-primary), var(--bs-info));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.career-card-modern:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.2);
  border-color: rgba(var(--bs-primary-rgb), 0.3);
}

.career-card-modern:hover::before {
  opacity: 1;
}

.career-badge {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  color: white;
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}

.career-badge.badge-success {
  background: linear-gradient(135deg, #10b981, #059669);
}

.career-badge.badge-info {
  background: linear-gradient(135deg, #3b82f6, #2563eb);
}

.career-badge.badge-warning {
  background: linear-gradient(135deg, #f59e0b, #d97706);
}

.career-icon-wrapper {
  width: 80px;
  height: 80px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  transition: all 0.3s ease;
}

.career-card-modern:hover .career-icon-wrapper {
  transform: scale(1.1) rotate(5deg);
}

.career-icon-wrapper i {
  font-size: 2rem;
  color: white;
}

.career-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--bs-body-color);
}

.career-salary {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  padding: 1rem;
  background: rgba(var(--bs-success-rgb), 0.1);
  border-left: 3px solid var(--bs-success);
  border-radius: 8px;
}

.career-salary i {
  color: var(--bs-success);
  font-size: 1.2rem;
}

.career-salary span {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--bs-success);
}

.career-salary small {
  color: var(--bs-secondary-color);
  font-size: 0.9rem;
}

.career-description {
  color: var(--bs-secondary-color);
  line-height: 1.7;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.career-responsibilities {
  background: rgba(var(--bs-info-rgb), 0.05);
  border-radius: 12px;
  padding: 1.25rem;
  margin-bottom: 1.5rem;
}

.career-responsibilities h6 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 1rem;
  color: var(--bs-info);
}

.career-responsibilities ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.career-responsibilities ul li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--bs-body-color);
  font-size: 0.9rem;
  line-height: 1.6;
}

.career-responsibilities ul li::before {
  content: '\f00c';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  position: absolute;
  left: 0;
  color: var(--bs-success);
  font-size: 0.75rem;
}

.career-skills-modern {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
}

.skill-badge {
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.2s ease;
  border: 2px solid transparent;
}

.skill-badge.skill-primary {
  background: rgba(var(--bs-primary-rgb), 0.1);
  color: var(--bs-primary);
  border-color: rgba(var(--bs-primary-rgb), 0.2);
}

.skill-badge.skill-primary:hover {
  background: rgba(var(--bs-primary-rgb), 0.2);
  transform: translateY(-2px);
}

.skill-badge.skill-success {
  background: rgba(var(--bs-success-rgb), 0.1);
  color: var(--bs-success);
  border-color: rgba(var(--bs-success-rgb), 0.2);
}

.skill-badge.skill-success:hover {
  background: rgba(var(--bs-success-rgb), 0.2);
  transform: translateY(-2px);
}

.skill-badge.skill-info {
  background: rgba(var(--bs-info-rgb), 0.1);
  color: var(--bs-info);
  border-color: rgba(var(--bs-info-rgb), 0.2);
}

.skill-badge.skill-info:hover {
  background: rgba(var(--bs-info-rgb), 0.2);
  transform: translateY(-2px);
}

.skill-badge.skill-warning {
  background: rgba(var(--bs-warning-rgb), 0.1);
  color: var(--bs-warning);
  border-color: rgba(var(--bs-warning-rgb), 0.2);
}

.skill-badge.skill-warning:hover {
  background: rgba(var(--bs-warning-rgb), 0.2);
  transform: translateY(-2px);
}

/* Responsive for Career Cards */
@media (max-width: 768px) {
  .careers-grid {
    grid-template-columns: 1fr;
  }
  
  .career-badge {
    position: static;
    display: inline-block;
    margin-bottom: 1rem;
  }
  
  .career-icon-wrapper {
    width: 60px;
    height: 60px;
  }
  
  .career-icon-wrapper i {
    font-size: 1.5rem;
  }
  
  .career-title {
    font-size: 1.25rem;
  }
}

/* ===== COMPARISON TABLE - MODERN DESIGN ===== */
.comparison-table-modern {
  background: rgba(var(--bs-body-bg-rgb), 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 20px;
  overflow: hidden;
  margin: 2rem 0;
}

.comparison-header {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr 1fr;
  background: linear-gradient(135deg, rgba(99,102,241,.15) 0%, rgba(139,92,246,.15) 100%);
  padding: 1.5rem;
  gap: 1rem;
  border-bottom: 2px solid rgba(var(--bs-primary-rgb), 0.3);
}

.comparison-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 1rem;
}

.comparison-col.header-col {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-size: 0.9rem;
}

.comparison-col.header-col i {
  font-size: 1.2rem;
  color: var(--bs-primary);
}

.comparison-icon {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.75rem;
}

.comparison-icon i {
  font-size: 1.3rem;
  color: white;
}

.comparison-col h5 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0;
}

.comparison-row {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr 1fr;
  gap: 1rem;
  padding: 1.5rem;
  border-bottom: 1px solid rgba(var(--bs-border-color-rgb), 0.1);
  transition: all 0.3s ease;
}

.comparison-row:hover {
  background: rgba(var(--bs-primary-rgb), 0.05);
}

.comparison-row:last-child {
  border-bottom: none;
}

.comparison-col.aspect-col {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
  text-align: left;
}

.comparison-col.aspect-col i {
  color: var(--bs-primary);
  font-size: 1.1rem;
}

.question-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.skills-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  text-align: left;
}

.skills-list span {
  padding: 0.4rem 0.8rem;
  background: rgba(var(--bs-primary-rgb), 0.1);
  border-radius: 6px;
  font-size: 0.85rem;
  border-left: 2px solid var(--bs-primary);
}

.tools-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.tool-badge {
  padding: 0.4rem 0.8rem;
  background: rgba(var(--bs-info-rgb), 0.1);
  border: 1px solid rgba(var(--bs-info-rgb), 0.3);
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--bs-info);
}

.role-badge {
  display: inline-block;
  padding: 0.4rem 0.9rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  color: white;
  margin: 0.25rem;
}

/* Example Box */
.example-box {
  margin-top: 2rem;
  background: linear-gradient(135deg, rgba(99,102,241,.08) 0%, rgba(139,92,246,.08) 100%);
  border: 1px solid rgba(var(--bs-primary-rgb), 0.2);
  border-radius: 20px;
  padding: 2rem;
}

.example-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.example-header i {
  font-size: 2rem;
  color: var(--bs-warning);
}

.example-header h4 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0;
}

.example-scenario {
  background: rgba(var(--bs-body-bg-rgb), 0.6);
  padding: 1.5rem;
  border-radius: 12px;
  margin-bottom: 1.5rem;
}

.scenario-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--bs-primary);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.scenario-text {
  font-size: 1.1rem;
  margin: 0;
}

.example-roles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.role-example {
  background: rgba(var(--bs-body-bg-rgb), 0.8);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  transition: all 0.3s ease;
}

.role-example:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.role-example-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  color: white;
  font-weight: 700;
}

.role-example-header i {
  font-size: 1.2rem;
}

.role-example p {
  padding: 1.25rem;
  margin: 0;
  line-height: 1.6;
}

/* Responsive Comparison Table */
@media (max-width: 991px) {
  .comparison-header,
  .comparison-row {
    grid-template-columns: 1fr;
  }
  
  .comparison-header {
    display: none;
  }
  
  .comparison-row {
    border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
    border-radius: 12px;
    margin-bottom: 1rem;
  }
  
  .comparison-col.aspect-col {
    background: rgba(var(--bs-primary-rgb), 0.1);
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    justify-content: center;
  }
  
  .comparison-col {
    padding: 0.75rem;
  }
  
  .comparison-col::before {
    content: attr(data-label);
    font-weight: 700;
    display: block;
    margin-bottom: 0.5rem;
    color: var(--bs-primary);
  }
}

/* ===== KEY TAKEAWAYS - MODERN GRID ===== */
.takeaways-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.takeaway-card {
  display: flex;
  gap: 1.25rem;
  padding: 1.75rem;
  background: rgba(var(--bs-body-bg-rgb), 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 16px;
  transition: all 0.3s ease;
}

.takeaway-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
  border-color: rgba(var(--bs-primary-rgb), 0.3);
}

.takeaway-icon {
  width: 60px;
  height: 60px;
  min-width: 60px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.takeaway-card:hover .takeaway-icon {
  transform: scale(1.1) rotate(5deg);
}

.takeaway-icon i {
  font-size: 1.5rem;
  color: white;
}

.takeaway-content h5 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--bs-body-color);
}

.takeaway-content p {
  font-size: 0.95rem;
  color: var(--bs-secondary-color);
  line-height: 1.6;
  margin: 0;
}

/* ===== QUIZ - MODERN DESIGN ===== */
.quiz-container-modern {
  background: linear-gradient(135deg, rgba(99,102,241,.08) 0%, rgba(139,92,246,.08) 100%);
  border: 2px solid rgba(var(--bs-primary-rgb), 0.2);
  border-radius: 24px;
  padding: 2.5rem;
  margin-top: 2rem;
}

.quiz-header-modern {
  text-align: center;
  margin-bottom: 2.5rem;
}

.quiz-icon-badge {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.quiz-icon-badge i {
  font-size: 2rem;
  color: white;
}

.quiz-header-modern h3 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

/* Responsive Takeaways */
@media (max-width: 768px) {
  .takeaways-grid {
    grid-template-columns: 1fr;
  }
  
  .takeaway-card {
    flex-direction: column;
    text-align: center;
  }
  
  .takeaway-icon {
    margin: 0 auto;
  }
  
  .example-roles {
    grid-template-columns: 1fr;
  }
}

/* ===== LESSON NAVIGATION - MODERN DESIGN ===== */
.lesson-nav-modern {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 4rem;
  padding-top: 3rem;
  border-top: 2px solid rgba(var(--bs-border-color-rgb), 0.2);
}

.nav-card-modern {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 1.5rem 2rem;
  background: rgba(var(--bs-body-bg-rgb), 0.6);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 16px;
  text-decoration: none;
  color: var(--bs-body-color);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.nav-card-modern::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--bs-primary), var(--bs-info));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.nav-card-modern:not(.disabled):hover {
  transform: translateX(8px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
  border-color: rgba(var(--bs-primary-rgb), 0.3);
}

.nav-card-modern:not(.disabled):hover::before {
  opacity: 1;
}

.nav-card-modern.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.nav-card-modern.nav-back {
  background: linear-gradient(135deg, rgba(99,102,241,.1) 0%, rgba(139,92,246,.1) 100%);
  border: 2px solid rgba(var(--bs-primary-rgb), 0.3);
}

.nav-card-modern.nav-back:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
}

.nav-card-icon {
  width: 50px;
  height: 50px;
  min-width: 50px;
  background: linear-gradient(135deg, var(--bs-primary), var(--bs-info));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.3rem;
  transition: all 0.3s ease;
}

.nav-card-modern:hover .nav-card-icon {
  transform: scale(1.1) rotate(5deg);
}

.nav-card-modern.disabled .nav-card-icon {
  background: rgba(var(--bs-secondary-rgb), 0.3);
}

.nav-card-content {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.nav-card-label {
  font-size: 0.85rem;
  color: var(--bs-secondary-color);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
}

.nav-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--bs-body-color);
}

.nav-prev-next {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.nav-card-modern.nav-prev .nav-card-icon {
  order: -1;
}

.nav-card-modern.nav-next {
  text-align: right;
}

/* ============================================
   Footer Styles
   ============================================ */
.lesson-footer {
  background: linear-gradient(180deg, transparent, rgba(var(--bs-primary-rgb), 0.03));
  border-top: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  padding: 4rem 0 2rem;
  margin-top: 5rem;
}

.footer-section {
  margin-bottom: 2rem;
}

.footer-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--bs-body-color);
  display: flex;
  align-items: center;
}

.footer-title i {
  color: var(--bs-primary);
}

.footer-resources {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 0.75rem;
}

.footer-resource-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: rgba(var(--bs-body-bg-rgb), 0.5);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 8px;
  color: var(--bs-body-color);
  text-decoration: none;
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

.footer-resource-link:hover {
  background: rgba(var(--bs-primary-rgb), 0.1);
  border-color: var(--bs-primary);
  color: var(--bs-primary);
  transform: translateX(4px);
}

.footer-resource-link i {
  font-size: 1.25rem;
  width: 24px;
  text-align: center;
  opacity: 0.7;
}

.footer-resource-link:hover i {
  opacity: 1;
}

#footerCompleteBtn {
  position: relative;
  overflow: hidden;
  border-width: 2px;
  font-weight: 600;
  transition: all 0.3s ease;
}

#footerCompleteBtn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(var(--bs-success-rgb), 0.3);
}

#footerCompleteBtn.completed {
  background: var(--bs-success);
  border-color: var(--bs-success);
  color: white;
}

#footerCompleteBtn.completed::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  transform: translate(-50%, -50%);
  animation: ripple 0.6s ease-out;
}

@keyframes ripple {
  to {
    width: 300px;
    height: 300px;
    opacity: 0;
  }
}

.footer-stats {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-stat {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  background: rgba(var(--bs-body-bg-rgb), 0.5);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 8px;
  font-size: 0.95rem;
}

.footer-stat i {
  font-size: 1.25rem;
  width: 24px;
  text-align: center;
  opacity: 0.7;
}

.footer-bottom {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p {
  margin: 0;
  color: var(--bs-secondary);
  font-size: 0.9rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  color: var(--bs-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--bs-primary);
}

/* Responsive Footer */
@media (max-width: 768px) {
  .lesson-footer {
    padding: 3rem 0 1.5rem;
  }
  
  .footer-resources {
    grid-template-columns: 1fr;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
  }
}

/* ============================================
   Code Example Box Styles
   ============================================ */
.code-example-box {
  background: rgba(var(--bs-body-bg-rgb), 0.5);
  border: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  border-radius: 12px;
  overflow: hidden;
  margin: 1.5rem 0;
}

.code-header {
  background: linear-gradient(135deg, rgba(var(--bs-primary-rgb), 0.1), rgba(var(--bs-info-rgb), 0.1));
  border-bottom: 1px solid rgba(var(--bs-border-color-rgb), 0.2);
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
}

.code-header i {
  color: var(--bs-primary);
}

.code-copy-btn {
  background: rgba(var(--bs-primary-rgb), 0.1);
  border: 1px solid rgba(var(--bs-primary-rgb), 0.3);
  color: var(--bs-primary);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 0.875rem;
}

.code-copy-btn:hover {
  background: rgba(var(--bs-primary-rgb), 0.2);
  transform: translateY(-2px);
}

.code-copy-btn.copied {
  background: rgba(var(--bs-success-rgb), 0.2);
  border-color: var(--bs-success);
  color: var(--bs-success);
}

.code-example-box pre {
  margin: 0;
  padding: 1.5rem;
  background: rgba(0, 0, 0, 0.3);
  overflow-x: auto;
}

.code-example-box code {
  font-family: 'JetBrains Mono', 'Courier New', monospace;
  font-size: 0.875rem;
  line-height: 1.6;
}

/* Quiz Explanation */
.quiz-question .explanation {
  display: none;
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(var(--bs-info-rgb), 0.1);
  border-left: 4px solid var(--bs-info);
  border-radius: 8px;
  font-size: 0.95rem;
  color: var(--bs-body-color);
}

.quiz-question .explanation i {
  color: var(--bs-info);
}

/* Quiz Answer States */
.quiz-options label.correct {
  background: rgba(var(--bs-success-rgb), 0.15);
  border-color: var(--bs-success);
}

.quiz-options label.correct::before {
  content: '✓';
  position: absolute;
  right: 1rem;
  color: var(--bs-success);
  font-weight: bold;
  font-size: 1.25rem;
}

.quiz-options label.incorrect {
  background: rgba(var(--bs-danger-rgb), 0.15);
  border-color: var(--bs-danger);
}

.quiz-options label.incorrect::before {
  content: '✗';
  position: absolute;
  right: 1rem;
  color: var(--bs-danger);
  font-weight: bold;
  font-size: 1.25rem;
}

.nav-card-modern.nav-next .nav-card-icon {
  order: 1;
}

/* Responsive Navigation */
@media (max-width: 768px) {
  .nav-prev-next {
    grid-template-columns: 1fr;
  }
  
  .nav-card-modern {
    padding: 1.25rem 1.5rem;
  }
  
  .nav-card-icon {
    width: 40px;
    height: 40px;
    min-width: 40px;
    font-size: 1.1rem;
  }
  
  .nav-card-title {
    font-size: 1rem;
  }
  
  .nav-card-modern:not(.disabled):hover {
    transform: translateY(-4px);
  }
}