body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f4f4f4;
  color: #333;
}
.header {
  background: #0056b3;
  color: #fff;
  padding: 2rem;
  text-align: center;
}
.btn {
  display: inline-block;
  padding: 10px 20px;
  background: #007bff;
  color: #fff;
  text-decoration: none;
  margin: 1rem 0;
  border-radius: 5px;
}
section {
  padding: 2rem;
  background: #fff;
  margin: 1rem auto;
  max-width: 800px;
  border-radius: 10px;
}
footer {
  text-align: center;
  padding: 1rem;
  background: #222;
  color: #fff;
}
.whatsapp {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 64px;
}