body {
  font-family: Arial, sans-serif;
  background-color: #0d1117;
}

h1 {
  text-align: center;
  margin-top: 30px;
  color: white;
}

.calculadora {
  width: 314px;
  margin: 0 auto;
  background-color: rgb(43, 60, 111);
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

#pantalla {
  width: 90%;
  padding: 10px;
  font-size: 20px;
  margin-bottom: 10px;
  text-align: right;
}

input[type="button"] {
  width: 70px;
  height: 40px;
  margin-right: 5px;
  margin-bottom: 5px;
  font-size: 16px;
  background-color: #eee;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

input.red{
  background-color: rgb(238, 0, 0);
}

input[type="button"]:hover {
  background-color: #ddd;
}

input.red:hover{
  background-color: rgb(217, 2, 2);
}

input[type="button"]:last-child {
  margin-right: 0;
}