/* ===== GitHub Master - Complete CSS Styles ===== */

/* CSS Variables for consistent theming */
:root {
  --primary-color: #0366d6;
  --primary-hover: #0256cc;
  --secondary-color: #586069;
  --success-color: #28a745;
  --danger-color: #d73a49;
  --warning-color: #f66a0a;
  --info-color: #0366d6;
  
  --bg-primary: #ffffff;
  --bg-secondary: #f6f8fa;
  --bg-tertiary: #fafbfc;
  --border-color: #e1e4e8;
  --text-primary: #24292e;
  --text-secondary: #586069;
  --text-muted: #6a737d;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
  
  --border-radius: 8px;
  --transition: all 0.3s ease;
}

/* Reset and Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans', Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-secondary);
}

/* Basic lesson card styles */
.lesson-card {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 20px;
  margin: 10px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

.lesson-card h3 {
  color: var(--primary-color);
  margin-bottom: 10px;
}

.lesson-btn {
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 4px;
  cursor: pointer;
  margin-top: 10px;
}

.lesson-btn:hover {
  background: var(--primary-hover);
}

.lessons-grid {
  display: none;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  padding: 20px;
}

.lessons-grid.active {
  display: grid;
}

.content-section {
  display: none;
  padding: 20px;
}

.content-section.active {
  display: block;
}

.lesson-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2000;
}

.lesson-content {
  background: white;
  max-width: 800px;
  max-height: 80vh;
  overflow-y: auto;
  padding: 20px;
  border-radius: var(--border-radius);
  position: relative;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 15px;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-secondary);
}

/* Navigation Header */
.navbar {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
}

.nav-logo i {
  font-size: 24px;
  color: var(--primary-color);
}

.nav-menu {
  display: flex;
  gap: 20px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  text-decoration: none;
  color: var(--text-secondary);
  border-radius: var(--border-radius);
  transition: var(--transition);
  font-weight: 500;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary-color);
  background-color: var(--bg-tertiary);
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}

.progress-indicator {
  display: flex;
  align-items: center;
  gap: 10px;
}

.progress-text {
  font-size: 14px;
  color: var(--text-secondary);
  white-space: nowrap;
}

.progress-bar {
  width: 120px;
  height: 6px;
  background-color: var(--bg-tertiary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--success-color), var(--primary-color));
  border-radius: 3px;
  transition: width 0.5s ease;
  width: 0%;
}

.data-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.data-btn {
  padding: 8px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-primary);
  color: var(--text-secondary);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
}

.data-btn:hover {
  background-color: var(--bg-tertiary);
  color: var(--primary-color);
}

/* Dropdown Menu */
.dropdown {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-md);
  padding: 8px 0;
  min-width: 200px;
  display: none;
  z-index: 1001;
}

.dropdown.active .dropdown-menu {
  display: block;
}

.dropdown-menu button {
  width: 100%;
  padding: 10px 16px;
  border: none;
  background: none;
  text-align: left;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.dropdown-menu button:hover {
  background-color: var(--bg-tertiary);
}

.dropdown-menu button.danger {
  color: var(--danger-color);
}

.dropdown-menu hr {
  border: none;
  height: 1px;
  background-color: var(--border-color);
  margin: 8px 0;
}

/* Main Content */
.main-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

.content-section {
  display: none;
}

.content-section.active {
  display: block;
}

/* Hero Section */
.hero-section {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  align-items: center;
  background-color: var(--bg-primary);
  padding: 40px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-sm);
  margin-bottom: 40px;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 16px;
}

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

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.hero-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background-color: var(--bg-secondary);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.cta-button {
  background: linear-gradient(135deg, var(--primary-color), #4a90e2);
  color: white;
  border: none;
  padding: 16px 32px;
  font-size: 1.1rem;
  font-weight: 600;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-md);
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(3, 102, 214, 0.3);
}

/* Hero Visual */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.github-illustration {
  width: 280px;
  height: 280px;
  background: linear-gradient(135deg, #f6f8fa, #e1e4e8);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.git-flow {
  display: flex;
  flex-direction: column;
  gap: 20px;
  align-items: center;
}

.commit-node {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary-color), #4a90e2);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  color: white;
  font-size: 24px;
  animation: pulse 2s infinite;
  box-shadow: var(--shadow-md);
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.1); opacity: 0.8; }
}

/* Learning Path Section */
.learning-path {
  margin-bottom: 40px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

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

.path-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.path-item {
  background-color: var(--bg-primary);
  padding: 32px 24px;
  border-radius: var(--border-radius);
  border: 2px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.path-item:hover {
  border-color: var(--primary-color);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.path-icon {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: 16px;
}

.path-item h3 {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.path-item p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.path-progress {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.progress-bar.small {
  flex: 1;
  height: 4px;
}

.path-progress span {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
  white-space: nowrap;
}

/* Section Headers */
.section-header {
  text-align: center;
  margin-bottom: 40px;
}

.section-description {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-top: 12px;
}

/* Course Tabs */
.course-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 32px;
  background-color: var(--bg-tertiary);
  padding: 8px;
  border-radius: var(--border-radius);
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}

.tab-button {
  padding: 12px 24px;
  border: none;
  background: none;
  color: var(--text-secondary);
  font-weight: 500;
  border-radius: calc(var(--border-radius) - 4px);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}

.tab-button.active, .tab-button:hover {
  background-color: var(--bg-primary);
  color: var(--primary-color);
  box-shadow: var(--shadow-sm);
}

/* Course Content */
.course-content {
  position: relative;
}

.course-panel {
  display: none;
}

.course-panel.active {
  display: block;
}

/* Lessons Grid */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.lesson-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.lesson-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.lesson-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 16px;
}

.lesson-card h3 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.lesson-card p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.lesson-meta {
  display: flex;
  gap: 16px;
  margin-bottom: 20px;
}

.duration, .difficulty {
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.difficulty.easy {
  color: var(--success-color);
}

.difficulty.medium {
  color: var(--warning-color);
}

.difficulty.hard {
  color: var(--danger-color);
}

.lesson-button {
  width: 100%;
  padding: 12px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.lesson-button:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
}

/* Coming Soon */
.coming-soon {
  text-align: center;
  padding: 80px 20px;
  color: var(--text-secondary);
}

.coming-soon i {
  font-size: 4rem;
  margin-bottom: 24px;
  color: var(--text-muted);
}

.coming-soon h3 {
  font-size: 1.8rem;
  margin-bottom: 16px;
}

/* Quiz and Practice Grids */
.quiz-options, .practice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.quiz-card, .practice-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 24px;
  text-align: center;
  transition: var(--transition);
}

.quiz-card:hover, .practice-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.quiz-icon, .practice-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 16px;
}

.quiz-card h3, .practice-card h3 {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.quiz-card p, .practice-card p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}

.quiz-meta {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.quiz-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.quiz-button, .practice-button {
  width: 100%;
  padding: 12px;
  background-color: var(--success-color);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.quiz-button:hover, .practice-button:hover {
  background-color: #22863a;
  transform: translateY(-1px);
}

/* Manual Section */
.manual-sidebar {
  position: fixed;
  left: 0;
  top: 64px;
  width: 280px;
  height: calc(100vh - 64px);
  background-color: var(--bg-primary);
  border-right: 1px solid var(--border-color);
  padding: 20px 0;
  overflow-y: auto;
  z-index: 100;
}

.manual-nav-item {
  padding: 12px 24px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  border-left: 3px solid transparent;
}

.manual-nav-item:hover, .manual-nav-item.active {
  background-color: var(--bg-tertiary);
  color: var(--primary-color);
  border-left-color: var(--primary-color);
}

.manual-content {
  margin-left: 300px;
  padding: 20px;
}

/* Content Areas */
.quiz-content-area, .practice-content-area {
  margin-top: 32px;
  padding: 24px;
  background-color: var(--bg-primary);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  display: none;
}

.quiz-content-area.active, .practice-content-area.active {
  display: block;
}

/* Buttons */
.btn {
  padding: 10px 20px;
  border: none;
  border-radius: var(--border-radius);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  font-size: 14px;
}

.btn-primary {
  background-color: var(--primary-color);
  color: white;
}

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

.btn-success {
  background-color: var(--success-color);
  color: white;
}

.btn-success:hover {
  background-color: #22863a;
}

.btn-secondary {
  background-color: var(--secondary-color);
  color: white;
}

.btn-secondary:hover {
  background-color: #444d56;
}

/* Footer */
.footer {
  background-color: var(--text-primary);
  color: var(--bg-primary);
  margin-top: 80px;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 32px;
}

.footer-section h3, .footer-section h4 {
  margin-bottom: 16px;
  color: var(--bg-primary);
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: 8px;
}

.footer-section a {
  color: #c6cbd1;
  text-decoration: none;
  transition: var(--transition);
}

.footer-section a:hover {
  color: var(--bg-primary);
}

.footer-bottom {
  border-top: 1px solid #444d56;
  padding: 20px;
  text-align: center;
  color: #c6cbd1;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background-color: var(--bg-primary);
  padding: 32px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  max-width: 90vw;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
}

.close {
  position: absolute;
  top: 16px;
  right: 20px;
  color: var(--text-muted);
  font-size: 28px;
  font-weight: bold;
  cursor: pointer;
  transition: var(--transition);
}

.close:hover {
  color: var(--danger-color);
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    height: auto;
    padding: 16px 20px;
    gap: 16px;
  }
  
  .nav-menu {
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .nav-controls {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }
  
  .hero-section {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 32px;
  }
  
  .hero-title {
    font-size: 2.2rem;
  }
  
  .hero-stats {
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  }
  
  .lessons-grid, .quiz-options, .practice-grid {
    grid-template-columns: 1fr;
  }
  
  .path-container {
    grid-template-columns: 1fr;
  }
  
  .manual-sidebar {
    position: static;
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border-color);
  }
  
  .manual-content {
    margin-left: 0;
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: 16px;
  }
  
  .hero-section {
    padding: 24px;
  }
  
  .hero-title {
    font-size: 1.8rem;
    flex-direction: column;
    gap: 8px;
  }
  
  .course-tabs {
    flex-direction: column;
    width: 100%;
  }
}