body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  margin: 0 auto;
  max-width: 800px;
  padding: 20px;
}

header {
  text-align: center;
  margin-bottom: 20px;
}

main {
  padding: 20px;
  background-color: #f9f9f9;
  border: 1px solid #ccc;
  border-radius: 5px;
}

h1,
h2,
h3 {
  color: #333;
}

h1 {
  font-size: 24px;
}

h2 {
  font-size: 20px;
  margin-bottom: 5px;
}

hr {
  border: none;
  border-top: 1px solid #ccc;
  margin: 20px 0;
}

a {
  color: #007bff;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  body {
    padding: 10px;
  }
  main {
    padding: 10px;
  }
  h1 {
    font-size: 20px;
  }
  h2 {
    font-size: 18px;
  }
}

abbr {
  border-bottom: 0.1em dotted #999;
  text-decoration: none;
}

iframe,
object {
  border: 1px solid #ccc;
  margin-top: 10px;
  margin-bottom: 30px;
}
section {
  margin-bottom: 40px;
}