.contenitore{
width: 300px;
margin-left:auto;
margin-right: auto;
margin-top: 50px;
background-color:inherit;
border-color: inherit;
border-style:solid;
border-radius: 14px;
box-shadow: 10px 10px 5px 12px;
background-image: url(https://comoperibambini.it/wp-content/uploads/2019/03/matematica-678x381.jpg);

}
.display {
  margin-left: auto;
  margin-right: auto;
  margin-top: 10px;
  margin-bottom: 10px;
}
.pulsante {
width: 50px;
height:50px;
border-style: solid;
border-radius:5px;
border-color: black;
color: black;
margin: 5px;
}
.tastiera {
  display: flex;

}

.sinistra {
  display: flex;
  width: 75%;
  flex-wrap: wrap;
  flex-direction: row;
}
.destra {
width:25%;
}

#diviso {
  background-color: violet;
}

#per {
  background-color: green;
}

#meno {
  background-color: #cb3234;
}

#più {
  background-color: #E5BE01;
  }