h1 {
  text-align: center;
  color: darkgreen;
  font-size: 2.2em;
}

.section-title {
  color: navy;
  border-bottom: 2px solid lightgray;
  padding-bottom: 4px;
}

.intro {
  background-color: #f2f9f2;
  padding: 10px;
  border-radius: 10px;
}

#main-title {
  background-color: #e0ffe0;
  padding: 12px;
  border-radius: 8px;
}

body {
  font-family: Arial, sans-serif;
  margin: 30px;
  line-height: 1.6;
  background-color: #fafafa;
}

ul, ol {
  margin-left: 40px;
}

.bst-image {
  display: block;
  margin: 20px auto;
  max-width: 400px;
  border: 2px solid #ccc;
  border-radius: 6px;
}