/* ============================================
   LESSON PAGE STYLES
   ============================================ */

/* Body layout - allow natural scrolling */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
  padding: 0;
  overflow-x: hidden;
}

/* ============================================
   LESSON CONTAINER LAYOUT
   ============================================ */

.lesson-container {
  display: flex;
  gap: 0;
  flex: 1;
  margin-top: 80px;
}

.lesson-sidebar {
  width: 280px;
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  padding: var(--spacing-md);
  position: sticky;
  top: 80px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--border-color);
}

.sidebar-header h3 {
  margin: 0;
  font-size: var(--font-size-base);
  font-weight: 600;
}

.sidebar-close {
  display: none;
  background: none;
  border: none;
  font-size: var(--font-size-xl);
  cursor: pointer;
  color: var(--text-primary);
}

.sidebar-content {
  margin-bottom: var(--spacing-lg);
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}

.sidebar-footer {
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  margin-top: auto;
  flex-shrink: 0;
}

/* ============================================
   SIDEBAR NAVIGATION - PHASES AND LESSONS
   ============================================ */

.sidebar-section {
  margin-bottom: var(--spacing-sm);
}

.sidebar-section-title {
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: white;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding: var(--spacing-sm) var(--spacing-md);
  margin-bottom: 0;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-sm);
  transition: all var(--transition-fast);
  user-select: none;
}

.sidebar-section-title i {
  font-size: var(--font-size-sm);
  transition: transform var(--transition-fast);
}

/* Phase Colors - All Use Primary Color */
.sidebar-section-title {
  background-color: var(--primary-color);
}

.sidebar-section-title:hover {
  opacity: 0.9;
  transform: translateX(2px);
}

.sidebar-section-title.collapsed i {
  transform: rotate(-90deg);
}

.sidebar-lessons {
  max-height: none;
  overflow: visible;
  transition: max-height var(--transition-base);
}

.sidebar-lessons.collapsed {
  max-height: 0;
  overflow: hidden;
}

.sidebar-week-header {
  padding: var(--spacing-xs) var(--spacing-md);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.8rem;
  text-transform: uppercase;
  margin-top: var(--spacing-sm);
  margin-bottom: var(--spacing-xs);
  letter-spacing: 0.5px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all 0.2s ease;
  user-select: none;
}

.sidebar-week-header:hover {
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding-left: var(--spacing-lg);
}

.sidebar-week-header i {
  transition: transform 0.2s ease;
  transform: rotate(90deg);
  font-size: 0.7rem;
}

.sidebar-week-wrapper {
  margin-bottom: var(--spacing-md);
}

.sidebar-days-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  max-height: 100%;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.sidebar-days-container.collapsed {
  max-height: 0;
}

.sidebar-item {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  margin: var(--spacing-xs) var(--spacing-sm);
  margin-left: var(--spacing-lg);
  background-color: var(--bg-primary);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  text-decoration: none;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
  font-size: var(--font-size-sm);
}

.sidebar-item:hover {
  background-color: var(--bg-tertiary);
  transform: translateX(4px);
  border-left-color: var(--primary-color);
}

.sidebar-item.active {
  background-color: var(--primary-color);
  color: white;
  border-left-color: var(--primary-dark);
  font-weight: 600;
}

.sidebar-item.active::before {
  content: '✓ ';
  margin-right: var(--spacing-xs);
}

.sidebar-item-meta {
  font-size: var(--font-size-xs);
  color: var(--text-light);
  display: block;
  margin-top: var(--spacing-xs);
}

.sidebar-item.active .sidebar-item-meta {
  color: rgba(255, 255, 255, 0.8);
}

/* ============================================
   TABLE OF CONTENTS - TOP BOX
   ============================================ */

.lesson-toc-box {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

.lesson-toc-box h3 {
  margin: 0 0 var(--spacing-md) 0;
  font-size: var(--font-size-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text-primary);
}

.toc-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.toc-content a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
  line-height: 1.4;
}

.toc-content a:hover {
  background-color: var(--bg-tertiary);
  border-left-color: var(--primary-color);
  transform: translateX(4px);
}

.toc-level-1 {
  padding-left: var(--spacing-md);
  font-weight: 600;
}

.toc-level-2 {
  padding-left: calc(var(--spacing-md) + var(--spacing-md));
  color: var(--text-secondary);
}

.toc-level-3 {
  padding-left: calc(var(--spacing-md) + var(--spacing-lg));
  color: var(--text-light);
  font-size: var(--font-size-xs);
}

/* ============================================
   LESSON MAIN CONTENT
   ============================================ */

.lesson-main {
  flex: 1;
  padding: var(--spacing-2xl);
  background-color: var(--bg-primary);
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}

.lesson-header {
  margin-bottom: var(--spacing-3xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 2px solid var(--border-color);
}

.lesson-meta {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
}

.phase-badge {
  display: inline-block;
  padding: var(--spacing-xs) var(--spacing-md);
  background-color: var(--primary-color);
  color: white;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.week-info {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  font-weight: 500;
}

.lesson-main h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.lesson-description {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  line-height: var(--line-height-relaxed);
  margin: 0;
}

/* ============================================
   LESSON CONTENT STYLING
   ============================================ */

.lesson-content {
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-3xl);
}

.lesson-content h2 {
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-lg);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  color: var(--text-primary);
}

.lesson-content h2:first-child {
  margin-top: 0;
  border-top: none;
  padding-top: 0;
}

.lesson-content h3 {
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.lesson-content h4,
.lesson-content h5,
.lesson-content h6 {
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
}

.lesson-content p {
  margin-bottom: var(--spacing-lg);
  color: var(--text-secondary);
}

.lesson-content ul,
.lesson-content ol {
  margin-bottom: var(--spacing-lg);
  color: var(--text-secondary);
}

.lesson-content li {
  margin-bottom: var(--spacing-md);
}

.lesson-content blockquote {
  border-left: 4px solid var(--primary-color);
  padding: var(--spacing-md) var(--spacing-lg);
  margin: var(--spacing-lg) 0;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-style: italic;
}

.lesson-content code {
  font-family: var(--font-family-mono);
  background-color: var(--bg-secondary);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  font-size: 0.9em;
  color: var(--primary-dark);
}

.lesson-content pre {
  background-color: #282c34;
  color: #abb2bf;
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  margin-bottom: var(--spacing-lg);
  border-left: 4px solid var(--primary-color);
}

.lesson-content pre code {
  background-color: transparent;
  color: inherit;
  padding: 0;
  font-size: 0.9em;
}

.lesson-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--spacing-lg);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.lesson-content table th {
  background-color: var(--primary-color);
  color: white;
  padding: var(--spacing-md);
  text-align: left;
  font-weight: 600;
}

.lesson-content table td {
  padding: var(--spacing-md);
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.lesson-content table tr:hover {
  background-color: var(--bg-secondary);
}

.lesson-content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  margin: var(--spacing-lg) 0;
  box-shadow: 0 4px 12px var(--shadow-color-dark);
}

/* Code Block with Line Numbers */
.lesson-content pre[class*="language-"] {
  position: relative;
}

.lesson-content .hljs {
  background-color: #282c34 !important;
  color: #abb2bf;
}

/* ============================================
   CALLOUT BOXES
   ============================================ */

.callout {
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-lg);
  border-left: 4px solid var(--border-color);
}

.callout.info {
  background-color: #e7f3ff;
  border-left-color: var(--info-color);
  color: var(--info-color);
}

.callout.warning {
  background-color: #fff8e1;
  border-left-color: var(--warning-color);
  color: var(--warning-color);
}

.callout.success {
  background-color: #f0f8f0;
  border-left-color: var(--success-color);
  color: var(--success-color);
}

.callout.danger {
  background-color: #fff5f5;
  border-left-color: var(--error-color);
  color: var(--error-color);
}

.callout-title {
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

/* ============================================
   TABLE OF CONTENTS
   ============================================ */

.lesson-toc {
  background-color: var(--bg-secondary);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-2xl);
  border-left: 4px solid var(--primary-color);
}

.lesson-toc h3 {
  margin-top: 0;
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-lg);
}

#tocContent {
  list-style: none;
}

#tocContent a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--text-secondary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

#tocContent a:hover {
  background-color: var(--bg-tertiary);
  color: var(--primary-color);
  transform: translateX(4px);
}

#tocContent a.toc-level-2 {
  padding-left: var(--spacing-xl);
}

#tocContent a.toc-level-3 {
  padding-left: var(--spacing-2xl);
}

/* ============================================
   LESSON NAVIGATION
   ============================================ */

.lesson-navigation {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-lg);
  padding: var(--spacing-xl);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-2xl);
}

.lesson-navigation .btn {
  flex: 0 1 auto;
}

.progress-info {
  text-align: center;
  color: var(--text-secondary);
  font-weight: 500;
}

#prevBtn:disabled,
#nextBtn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 1024px) {
  .lesson-sidebar {
    width: 250px;
    padding: var(--spacing-md);
  }

  .lesson-toc-sidebar {
    width: 250px;
    padding: var(--spacing-md);
  }

  .lesson-main {
    padding: var(--spacing-xl);
  }
}

@media (max-width: 768px) {
  .lesson-container {
    flex-direction: column;
  }

  /* Hide sidebar by default */
  .lesson-sidebar {
    width: 100%;
    max-height: 0;
    overflow: hidden;
    padding: 0;
    border-right: none;
    border: 1px solid var(--border-color);
    transition: max-height var(--transition-normal);
  }

  .lesson-sidebar.open {
    max-height: 70vh;
    padding: var(--spacing-md);
    overflow-y: auto;
  }

  .sidebar-close {
    display: block;
  }

  .lesson-main {
    padding: var(--spacing-lg);
  }

  .sidebar-toggle {
    display: flex !important;
  }

  .lesson-main h1 {
    font-size: var(--font-size-3xl);
  }

  .lesson-navigation {
    flex-wrap: wrap;
  }

  .lesson-navigation .btn {
    flex: 1;
    min-width: 120px;
  }

  .progress-info {
    width: 100%;
    order: 3;
  }

  .lesson-toc-box {
    display: none;
  }

  .sidebar-footer{
    /* display: none; */
  }
}

@media (max-width: 480px) {
  .lesson-main {
    padding: var(--spacing-md);
  }

  .lesson-main h1 {
    font-size: var(--font-size-2xl);
  }

  .lesson-header {
    margin-bottom: var(--spacing-2xl);
  }

  .lesson-navigation {
    flex-direction: column;
  }

  .lesson-navigation .btn {
    width: 100%;
  }

  .progress-info {
    order: 0;
    width: 100%;
    margin-bottom: var(--spacing-md);
  }

  .lesson-content {
    font-size: var(--font-size-sm);
  }

  .lesson-content pre {
    padding: var(--spacing-md);
    font-size: 0.8em;
  }

  .lesson-content table {
    font-size: var(--font-size-xs);
  }

  .callout {
    padding: var(--spacing-md);
  }
}

/* ============================================
   SCROLLBAR STYLING
   ============================================ */

.lesson-main::-webkit-scrollbar,
.lesson-sidebar::-webkit-scrollbar {
  width: 8px;
}

.lesson-main::-webkit-scrollbar-track,
.lesson-sidebar::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

.lesson-main::-webkit-scrollbar-thumb,
.lesson-sidebar::-webkit-scrollbar-thumb {
  background: var(--primary-color);
  border-radius: 4px;
}

.lesson-main::-webkit-scrollbar-thumb:hover,
.lesson-sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* ============================================
   ANIMATION
   ============================================ */

.lesson-content {
  animation: fadeIn 0.5s ease-out;
}

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

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
  .lesson-sidebar,
  .lesson-navigation,
  .sidebar-toggle,
  header,
  footer {
    display: none;
  }

  .lesson-main {
    padding: 0;
  }

  .lesson-content {
    color: black;
  }

  .lesson-content code,
  .lesson-content pre {
    background-color: #f5f5f5;
    border: 1px solid #ddd;
  }
}

/* Footer styling */
footer {
  background-color: var(--text-primary);
  color: white;
  padding: var(--spacing-lg) var(--spacing-md);
  text-align: center;
  margin-top: 0;
  flex-shrink: 0;
}