dateinput.css

input[name="dob"]:before {
  content: "Date of Birth";
  color: #aaa;
  margin-right: 0.5em;
}

input[name="dob"]:focus:before,
input[name="dob"]:valid:before {
  content: "";
}

input[name="dob"]:required:invalid::-webkit-datetime-edit {
  color: transparent;
}
input[name="dob"]:focus::-webkit-datetime-edit {
  color: black !important;
}