body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.buttons {
    display: flex;
    flex-direction: column;
    justify-self: center;
}

.screen {
    padding: 10px 20px;
    border: 2px black solid;
    border-radius: 5px;
    margin-bottom: 20px;
    text-align: right;
    word-wrap: break-word;
    word-break: break-all;
  }
  
  .screen-last {
    min-height: 32px;
    font-size: 20px;
  }
  
  .screen-current {
    min-height: 64px;
    font-size: 40px;
  }

button{
    background-color: grey;
    width: 50px;
    height: 50px;
    font-size: large;
}

button:hover {
    background-color: lightgrey;
}