body {
  font-family: Arial, sans-serif;
  background: #f2f2f2;
  padding: 20px;
  text-align: center;
}

form {
  margin-bottom: 30px;
}

input, button {
  margin: 8px;
  padding: 10px;
  font-size: 16px;
  width: 250px;
}

button {
  background: green;
  color: white;
  border: none;
  cursor: pointer;
}

.receipt {
  background: white;
  border: 1px solid #ccc;
  padding: 20px;
  max-width: 350px;
  margin: auto;
  text-align: left;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

.receipt h2 {
  color: green;
  text-align: center;
}

.demo {
  color: red;
  text-align: center;
  margin-top: 10px;
  font-size: 12px;
}