body {
  font-family: sans-serif;
  margin: 0;
}
#calculadora {
  width: 200px;
  background-color: #eee7dd;
  padding: 20px;
  /* border-radius: 5px; */
  /* box-shadow: 0 2px 8px #00000077; */
  /* margin: 15px auto; */
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 5px;
  grid-template-rows: auto repeat(5, 40px);
}
button {
  padding: 0.25em;
  color: #cc1a1a;
  border-radius: 4px;
  background-color: #f1ede7;
  border-color: rgb(211, 211, 211);
  font-weight: bold;
  font-family: sans-serif;
}
button:hover{
    background-color: #d8d8d869;
}
button[onclick^="incluirDigito"]{
    color: #1a3bcc;
}
#display {
  padding: 3px 10px;
  font-size: 1.4em;
  text-align: right;
  background-color: #eeeeee;
  border: 2px solid gray;
  border-radius: 4px;
  box-shadow: inset 2px 2px 0 white;
  margin-bottom: 15px;
  grid-column: 1 / -1;
}
.mais {
  grid-row: 5 / 7;
  grid-column: 4 / 5;
}
.zero {
  grid-column: 1 / 3;
}