body {
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu,
    Cantarell, sans-serif;
  line-height: 1.6;
  color: #333;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  background-color: #f9f9f9;
}
header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 2rem;
  border-radius: 10px;
  margin-bottom: 2rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}
header h1 {
  margin: 0;
  font-size: 2.5rem;
  font-weight: 300;
}
.course-description {
  margin-top: 1rem;
  font-size: 1.1rem;
  opacity: 0.9;
}
.course-info {
  background: white;
  padding: 1.5rem;
  border-radius: 8px;
  margin-bottom: 2rem;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.course-info h2 {
  margin-top: 0;
  color: #4a5568;
  border-bottom: 2px solid #e2e8f0;
  padding-bottom: 0.5rem;
}
.course-info ul {
  list-style: none;
  padding: 0;
}
.course-info li {
  margin: 0.5rem 0;
  padding: 0.5rem;
  background: #f7fafc;
  border-radius: 4px;
}
.course-section {
  background: #4299e1;
  color: white;
  padding: 1.5rem;
  border-radius: 8px;
  margin: 2rem 0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.course-section h2 {
  margin: 0;
  font-weight: 400;
}
.lesson {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  margin: 2rem 0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  border-left: 4px solid #4299e1;
}
.lesson h3 {
  margin-top: 0;
  color: #2d3748;
  font-size: 1.5rem;
}
.lesson-description {
  margin: 1rem 0;
  padding: 1rem;
  background: #f7fafc;
  border-radius: 4px;
  border-left: 3px solid #4299e1;
}
.item {
  margin: 1.5rem 0;
  padding: 1rem;
  border-radius: 6px;
  background: #fafafa;
  border: 1px solid #e2e8f0;
}
.item h4 {
  margin-top: 0;
  color: #4a5568;
  font-size: 1.2rem;
  text-transform: capitalize;
}
.text-item {
  background: #f0fff4;
  border-left: 3px solid #48bb78;
}
.list-item {
  background: #fffaf0;
  border-left: 3px solid #ed8936;
}
.knowledge-check {
  background: #e6fffa;
  border-left: 3px solid #38b2ac;
}
.multimedia-item {
  background: #faf5ff;
  border-left: 3px solid #9f7aea;
}
.interactive-item {
  background: #fff5f5;
  border-left: 3px solid #f56565;
}
.unknown-item {
  background: #f7fafc;
  border-left: 3px solid #a0aec0;
}
.answers {
  margin: 1rem 0;
}
.answers h5 {
  margin: 0.5rem 0;
  color: #4a5568;
}
.answers ol {
  margin: 0.5rem 0;
  padding-left: 1.5rem;
}
.answers li {
  margin: 0.3rem 0;
  padding: 0.3rem;
}
.correct-answer {
  background: #c6f6d5;
  border-radius: 3px;
  font-weight: bold;
}
.correct-answer::after {
  content: " ✓";
  color: #38a169;
}
.feedback {
  margin: 1rem 0;
  padding: 1rem;
  background: #edf2f7;
  border-radius: 4px;
  border-left: 3px solid #4299e1;
  font-style: italic;
}
.media-info {
  background: #edf2f7;
  padding: 1rem;
  border-radius: 4px;
  margin: 0.5rem 0;
}
.media-info strong {
  color: #4a5568;
}
hr {
  border: none;
  height: 2px;
  background: linear-gradient(to right, #667eea, #764ba2);
  margin: 2rem 0;
  border-radius: 1px;
}
ul {
  padding-left: 1.5rem;
}
li {
  margin: 0.5rem 0;
}