.calculator {
    max-width: 300px;
    margin: 50px auto;
    padding: 20px;
    border: 3px solid #7c8bc0;
    border-style: inset;
    border-radius: 10px;
    text-align: center;
  }
  
  input[type="number"], button {
    margin: 5px;
    padding: 8px;
  }
  
  button {
    cursor: pointer;
    background-color: #7c8bc0;
    color: #fff;
    border: burlywood;
    border-radius: 3px;
  }
  
  button:hover {
    background-color: #0056b3;
  }
  
  p {
    margin-top: 10px;
    font-weight: bold;
  }