body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}

header {
  background-color: #0066cc;
  color: white;
  padding: 10px 20px;
  text-align: center;
}

nav a {
  color: white;
  margin: 0 10px;
  text-decoration: none;
}

main {
  padding: 20px;
}

footer {
  background-color: #eee;
  text-align: center;
  padding: 10px;
  margin-top: 20px;
}

.product {
  border: 1px solid #ddd;
  padding: 10px;
  margin-bottom: 10px;
  max-width: 300px;
}

.btn {
  background-color: #28a745;
  color: white;
  padding: 10px;
  text-decoration: none;
}