body {
  font-family: Arial, sans-serif;
  background: #f2f2f2;
  margin: 0;
  padding: 0;
}
header {
  background: #004080;
  color: white;
  padding: 15px;
  text-align: center;
}
nav a {
  margin: 0 10px;
  color: white;
  text-decoration: none;
  font-weight: bold;
}
main {
  padding: 20px;
  text-align: center;
}
form {
  margin: 20px auto;
  padding: 15px;
  background: white;
  border-radius: 8px;
  width: 300px;
  box-shadow: 0 0 5px rgba(0,0,0,0.2);
}
input, button {
  padding: 10px;
  margin: 10px 0;
  width: 90%;
  border: 1px solid #ccc;
  border-radius: 5px;
}
button {
  background: #004080;
  color: white;
  border: none;
  cursor: pointer;
}
button:hover {
  background: #0066cc;
}
.success {
  color: green;
  font-weight: bold;
}
.error {
  color: red;
  font-weight: bold;
}