body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #f4f4f4;
  color: #000;
}

h1, h2, h3 {
  margin: 0.5em 0;
}

a {
  color: #0066cc;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

nav {
  background-color: #333;
  text-align: center;
  padding: 10px;
}

nav a {
  color: white;
  padding: 10px 15px;
  text-decoration: none;
  display: inline-block;
}

nav a:hover {
  background-color: #ddd;
  color: black;
}

.row {
  padding: 20px;
  text-align: center;
}