Onchange input

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<input type="text" class="input">

CSS

.input {
  border: 1px solid #ccc;
}
.input.text {
  border: 2px solid #000;
}
.input::valid {
  border: 2px solid red !important;
}