.calculadora {
  width: 300px;
  margin: 40px auto;
  border-radius: 10px;
  padding: 10px;

}

#display {
  height: 30px;
  background: #ffffff;
  font-size: 2rem;
  text-align: right;
  padding: 10px;
  border-radius: 5px;
  user-select: none;
  overflow: hidden;
  border: solid black 1px;
}

.botones {
  display: flex;
  flex-wrap: wrap;
  gap: 3px;
  margin-top: 10px;
}

.botones button {
  flex: 1 1 23%; 
  font-size: 18px;
  box-sizing: border-box;
}

button {
  padding: 20px;
  font-size: 1.5rem;
  cursor: pointer;
  border: none;
  border-radius: 5px;
  background: #000000;
  color: white;
}