body {
  background-color: black;
  font-family: Arial, Helvetica, sans-serif;
}
button {
  height: 48px;
  width: 48px;
  color: white;
  border-radius: 50px;
  margin-right: 4px;
  border: none;
  font-size: 20px;
  background-color: rgb(54, 53, 53);
}
.op {
  background-color: orange;
}
.clear-button {
  font-size: 15px;
}
.calculation {
  color: white;
  font-size: 45px;
  margin-bottom: 4px;
}