body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  color: #003366;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
.container {
  background: rgba(255, 255, 255, 0.9);
  padding: 2em;
  border-radius: 10px;
  text-align: center;
}
.btn {
  display: block;
  margin: 1em auto;
  padding: 1em;
  background: #cce6ff;
  color: #003366;
  text-decoration: none;
  border-radius: 5px;
  width: 80%;
  max-width: 300px;
}