/* Course Detail Page Styles */
:root {
  --primary-color: #2563eb;
  --primary-dark: #1d4ed8;
  --secondary-color: #64748b;
  --accent-color: #f59e0b;
  --success-color: #10b981;
  --danger-color: #ef4444;
  --warning-color: #f59e0b;
  --info-color: #3b82f6;
  --light-bg: #f8fafc;
  --card-bg: #ffffff;
  --border-color: #e2e8f0;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --border-radius: 12px;
  --border-radius-sm: 8px;
}

/* Base Styles */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--light-bg);
  color: var(--text-primary);
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

/* Header Section */
.course-header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.breadcrumb-nav {
  display: flex;
  align-items: center;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  transition: all 0.2s ease;
}

.back-btn:hover {
  background-color: var(--light-bg);
  color: var(--primary-color);
  text-decoration: none;
}

.back-btn i {
  font-size: 0.875rem;
}

/* Main Content */
.course-main {
  padding: 2rem 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* Loading State */
.loading-spinner {
  padding: 4rem 0;
}

.loading-spinner .spinner-border {
  width: 3rem;
  height: 3rem;
}

/* Error State */
.error-state {
  padding: 4rem 0;
  text-align: center;
}

/* Course Hero Section */
.course-hero {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 3rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-md);
}

.course-category {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.course-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  line-height: 1.2;
}

.course-description {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.course-meta {
  display: flex;
  gap: 2rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.meta-item i {
  color: var(--primary-color);
  font-size: 1.125rem;
}

.course-skills h5 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.skills-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-badge {
  background: var(--light-bg);
  color: var(--text-primary);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.skill-badge:hover {
  background: var(--primary-color);
  color: white;
  transform: translateY(-1px);
}

/* Course Image */
.course-image-container {
  position: relative;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  height: 300px;
}

.course-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.course-overlay {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

.difficulty-badge {
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.difficulty-badge.beginner {
  background: rgba(16, 185, 129, 0.9);
}

.difficulty-badge.intermediate {
  background: rgba(245, 158, 11, 0.9);
}

.difficulty-badge.advanced {
  background: rgba(239, 68, 68, 0.9);
}

/* Course Content */
.course-content {
  margin-top: 2rem;
}

.content-section {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-md);
}

.section-header {
  margin-bottom: 2rem;
  text-align: center;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}

.section-header h2 i {
  color: var(--primary-color);
  font-size: 1.75rem;
}

.section-header p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin: 0;
}

/* Syllabus */
.syllabus-container {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.syllabus-item {
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
  padding: 1.5rem;
  border-radius: var(--border-radius-sm);
  background: var(--light-bg);
  border-left: 4px solid var(--primary-color);
  transition: all 0.2s ease;
}

.syllabus-item:hover {
  background: white;
  box-shadow: var(--shadow-md);
  transform: translateX(5px);
}

.syllabus-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  background: var(--primary-color);
  color: white;
  border-radius: 50%;
  font-weight: 700;
  font-size: 1.125rem;
  flex-shrink: 0;
}

.syllabus-content h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.syllabus-content p {
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

/* Learning Outcomes */
.outcomes-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1rem;
}

.outcome-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: var(--light-bg);
  border-radius: var(--border-radius-sm);
  transition: all 0.2s ease;
}

.outcome-item:hover {
  background: white;
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}

.outcome-item i {
  color: var(--success-color);
  font-size: 1.25rem;
  flex-shrink: 0;
  transition: all 0.2s ease;
}

.outcome-item:hover i {
  transform: scale(1.1);
}

.outcome-item span {
  font-weight: 500;
  color: var(--text-primary);
}

/* Sidebar */
.course-sidebar {
  position: sticky;
  top: 2rem;
}

.sidebar-card {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-md);
}

.sidebar-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sidebar-card h3 i {
  color: var(--primary-color);
}

.detail-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border-color);
}

.detail-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.detail-item i {
  color: var(--primary-color);
  font-size: 1.125rem;
  width: 1.5rem;
  text-align: center;
}

.detail-item div {
  flex: 1;
}

.detail-item strong {
  display: block;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.detail-item span {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.difficulty-text {
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

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

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

.certificate-features {
  margin-top: 1rem;
}

.feature-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.feature-item i {
  color: var(--success-color);
  font-size: 1rem;
}

.enroll-section {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  border-radius: var(--border-radius);
  padding: 2rem;
  text-align: center;
  color: white;
}

.enroll-section .btn {
  background: white;
  color: var(--primary-color);
  border: none;
  font-weight: 600;
  padding: 1rem 2rem;
  font-size: 1.125rem;
  transition: all 0.2s ease;
}

.enroll-section .btn:hover {
  background: var(--light-bg);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.enroll-section p {
  margin: 1rem 0 0 0;
  opacity: 0.9;
  font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 991.98px) {
  .course-hero {
    padding: 2rem;
  }
  
  .course-title {
    font-size: 2rem;
  }
  
  .course-meta {
    gap: 1rem;
  }
  
  .syllabus-item {
    flex-direction: column;
    text-align: center;
  }
  
  .syllabus-number {
    align-self: center;
  }
  
  .course-sidebar {
    position: static;
    margin-top: 2rem;
  }
}

@media (max-width: 767.98px) {
  .course-hero {
    padding: 1.5rem;
  }
  
  .course-title {
    font-size: 1.75rem;
  }
  
  .course-description {
    font-size: 1rem;
  }
  
  .course-meta {
    flex-direction: column;
    gap: 0.75rem;
  }
  
  .content-section {
    padding: 1.5rem;
  }
  
  .section-header h2 {
    font-size: 1.5rem;
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .sidebar-card {
    padding: 1rem;
  }
  
  .enroll-section {
    padding: 1.5rem;
  }
}

@media (max-width: 575.98px) {
  .container {
    padding: 0 0.75rem;
  }
  
  .course-hero {
    padding: 1rem;
  }
  
  .course-title {
    font-size: 1.5rem;
  }
  
  .content-section {
    padding: 1rem;
  }
  
  .syllabus-item {
    padding: 1rem;
  }
  
  .syllabus-number {
    width: 2.5rem;
    height: 2.5rem;
    font-size: 1rem;
  }
  
  .syllabus-content h4 {
    font-size: 1.125rem;
  }
}