.digit-group input {
  width: 45px;
  height: 40px;
  border: solid gray 1px;
  line-height: 50px;
  text-align: center;
  font-size: 24px;
  font-family: "Raleway", sans-serif;
  font-weight: 200;
  color: black;
  margin: 0 2px;
}
.digit-group .splitter {
  padding: 0 5px;
  color: black;
  font-size: 24px;
}

.prompt {
  margin-bottom: 20px;
  font-size: 20px;
  font-weight: lighter;
  color: black;
}

@media only screen and (max-width: 600px) {
  .digit-group input {
    width: 30px;
    height: 30px;
    border: solid gray 1px;
    line-height: 40px;
    text-align: center;
    font-size: 20px;
    font-family: "Raleway", sans-serif;
    font-weight: 200;
    color: black;
    margin: 0 2px;
  }
  .digit-group .splitter {
    padding: 0 4px;
    color: black;
    font-size: 20px;
  }
}