.course-content {
  width: 100%;
  max-width: 800px;
  margin: auto;
  background-color: #333;
  color: #fff;
  font-family: Arial, sans-serif;
}

.course-section {
  border-bottom: 1px solid #444;
}

.section-header {
  padding: 15px;
  cursor: pointer;
  background-color: #fcfcfc;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.section-header:hover {
  background-color: #111;
}

.section-header h2 {
  margin: 0;
  font-size: 1.2rem;
}

.section-header .toggle-icon {
  font-size: 1.2rem;
}

.section-content {
  display: none;
  padding: 15px;
}

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

.lesson {
  margin: 10px 0;
  display: flex;
  justify-content: space-between;
}

.lesson a {
  color: #00f;
}

.lesson-duration {
  color: #aaa;
}