body {
  font-family: Arial, sans-serif;
  max-width: 800px;
  margin: 40px auto;
  padding: 20px;
  background: #f4f4f4;
  color: #222;
}

h1 {
  text-align: center;
  color: #2c3e50;
  font-size: 42px;
}

h2 {
  color: #34495e;
}

p {
  line-height: 1.6;
}

hr {
  border: 0;
  border-top: 1px solid #ccc;
}

a {
  color: #3498db;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}
.topnav {
  background-color: #333;
  overflow: hidden;
}

.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

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

.topnav a.active {
  background-color: #04AA6D;
  color: white;
}