* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header Section */
.header {
  position: relative;
  height: 400px;

  overflow: hidden;
}

.header-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.header-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(0, 123, 255, 0.397),
    rgba(80, 80, 80, 0.555)
  );
  display: flex;
  align-items: center;
  justify-content: center;
}

.header-content {
  text-align: center;
  color: white;
  z-index: 2;
}

.course-title {
  font-size: 3rem;
  font-weight: bold;
  margin-bottom: 1rem;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.course-subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
}

/* Main Content */
.main-content {
  padding: 4rem 0;
}

.course-description {
  background: white;
  padding: 3rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  margin-bottom: 3rem;
}

.description-title {
  color: #007bff;
  font-size: 2rem;
  margin-bottom: 1.5rem;
  border-bottom: 3px solid #79d559;
  padding-bottom: 0.5rem;
}

.description-text {
  font-size: 1.1rem;
  color: #555;
  margin-bottom: 1.5rem;
}

.course-highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.highlight-item {
  color: white;
  padding: 1.5rem;
  border-radius: 8px;
  text-align: center;
}

.highlight-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

/* Course Subdivisions */
.course-subdivisions {
  background: white;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.subdivisions-title {
  background: linear-gradient(135deg, #007bff, #79d559);
  color: white;
  padding: 2rem;
  font-size: 2rem;
  text-align: center;
}

.accordion {
  border: none;
}

.accordion-item {
  border-bottom: 1px solid #e9ecef;
}

.accordion-item:last-child {
  border-bottom: none;
}

.accordion-header {
  background: #f8f9fa;
  padding: 1.5rem 2rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all 0.3s ease;
  border: none;
  width: 100%;
  text-align: left;
  font-size: 1.1rem;
  font-weight: 600;
  color: #333;
}

.accordion-header:hover {
  background: #e9ecef;
  color: #007bff;
}

.accordion-header.active {
  background: #007bff;
  color: white;
}

.accordion-icon {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
}

.accordion-header.active .accordion-icon {
  transform: rotate(180deg);
}

.accordion-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  background: white;
}

.accordion-content.active {
  max-height: 500px;
}

.accordion-body {
  padding: 2rem;
  color: #555;
  line-height: 1.8;
}

.lesson-list {
  list-style: none;
  margin-top: 1rem;
}

.lesson-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid #f0f0f0;
  position: relative;
  padding-left: 1.5rem;
}

.lesson-list li:before {
  content: "✓";
  color: #79d559;
  font-weight: bold;
  position: absolute;
  left: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
  .course-title {
    font-size: 2rem;
  }

  .course-description {
    padding: 2rem;
  }

  .accordion-header {
    padding: 1rem 1.5rem;
    font-size: 1rem;
  }

  .accordion-body {
    padding: 1.5rem;
  }

  .course-highlights {
    grid-template-columns: 1fr;
  }
}