body {
  display: grid;
  grid-template-columns: repeat(4, 480px);
  grid-template-rows: repeat(5, 540px);
}
.calcolatrice {
    grid-area: 1 / 2 / 1 / 4;
  border: 2px solid blue;
  width: 50%;
  padding-left: 29%;
  padding-right: 20%;
  padding-top: 4%;
}

.pulsanti {
  border: 2px solid red;
  display: grid;
  grid-template-columns: repeat(4, 50px);
  grid-template-rows: repeat(5, 50px);
  grid-column-gap: 50px;
  grid-row-gap: 50px;
}
#output {
  grid-area: 1 / 1 / 1 / 5;
}

#sette {
  grid-area: 2 / 1 / 3 / 2;
}

#otto {
  grid-area: 2 / 2 / 3 / 3;
}

#nove {
  grid-area: 2 / 3 / 3 / 4;
}

#diviso {
  grid-area: 2 / 4 / 3 / 5;
}

#quattro {
  grid-area: 3 / 1 / 4 / 2;
}

#cinque {
  grid-area: 3 / 2 / 4 / 3;
}

#sei {
  grid-area: 3 / 3 / 4 / 4;
}

#per {
  grid-area: 3 / 4 / 4 / 5;
}

#uno {
  grid-area: 4 / 1 / 5 / 2;
}

#due {
  grid-area: 4 / 2 / 5 / 3;
}

#tre {
  grid-area: 4 / 3 / 5 / 4;
}

#meno {
    grid-area: 4 / 4 / 5 / 5;
  }

#zero {
  grid-area: 5 / 1 / 6 / 2;
}

#virgola {
  grid-area: 5 / 2 / 6 / 3;
}

#uguale {
  grid-area: 5 / 3 / 6 / 4;
}

#più {
    grid-area: 5 / 4 / 6 / 5;
}