html,body {
    font-family: 'Roboto';
    height: 100%;
    width: 100%;
    background-color: lightgreen;
}

.button{
font-size: 20px;
font-family: serif;
font-weight: bold;
width: 65px;
padding: 10px;
margin:1px;
border:3px solid black;
border-radius: 15px;
cursor:pointer;
background-color: rgb(218, 218, 218);
}

.container{
    border: 3px solid black;
    height: 440px;
    width: 400px;
} 

.row{
  margin: 8px 0px;
}

.row input{
  font-size: 40px;
  margin: 5px;
  padding: 10px 10px;
  width: 330px;
  height: 50px;
  border-radius: 15px;
  text-align: right;
  background-color: lightcyan;
  border: 4px solid black;
}