.calculator {
  border: 1px solid black;
  padding: 20px;
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

form {
  margin-bottom: 20px;
}

label {
  display: block;
  margin-bottom: 10px;
}

input[type="number"] {
  width: 100%;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
  margin-bottom: 20px;
}

input[type="button"], input[type="reset"] {
  background-color: #4CAF50;
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  margin-right: 10px;
}

input[type="button"]:hover, input[type="reset"]:hover {
  background-color: #3e8e41;
}

.result {
  font-size: 24px;
}