.calculator{
  max-width: 600px;
  margin: 0 auto;
}

button {
  background-color: #007bff;
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 1rem;
  margin-top: 10px;
}
input {
  width: 30%;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 5px;
  font-size: 1rem;
  margin-top: 5px;
}

h1 {
  text-align: center;
  font-size: 2rem;
  font-family: 'Roboto', sans-serif;
}
label {
  margin-bottom: 10px;
  font-family: 'Roboto', sans-serif;
}