body {
  background-color: whitesmoke;
}

.centered-div {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -90%);
  margin-bottom: 10px;
  height: 300px;
  width: 300px;
  align-items: center;
  text-align: center;
}

input[type="number"] {
  margin-bottom: 2px;
  border: 1px thin black;
}

.form {
  padding: 10px;
  margin: 10px;
}