JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://rawgit.com/RobinHerbots/jquery.inputmask/3.x/dist/jquery.inputmask.bundle.js"></script>
<form action="" method="post" name="form" id="form">
<table style="width: 70%" id="Table" name="Table">
    <tr>
        <th>Time</th>
    </tr>
    <tr>
        <td>
            <p class="null_temp">
                <input type="text" name="temp1" id="temp1" placeholder="Time" size="10" maxlength="8" value="" class="total_time_regex" onsubmit="myFunction()" />
            </p>
        </td>
    </tr>
</table>
<input type="button" id="btnAdd" name="btnAdd" value="Add More" class="button" />
<button type="submit" id="signup" value="Sign me up!">Sign Up</button>
</form>

<script>
function myFunction() {
    var x = document.getElementsByClassName("total_time_regex");
    var i;
    for (i = 0; i < x.length; i++) {
        x[i].style.backgroundColor = "red";
    }
}
</script>

CSS

#Table {
    font-family:"Trebuchet MS", Arial, Helvetica, sans-serif;
    border-collapse:collapse;
}
#Table td, #Table th {
    font-size:1em;
    border:1px solid #98bf21;
    padding:3px 7px 2px 7px;
}
#Table th {
    font-size:1.4em;
    text-align:left;
    padding-top:5px;
    padding-bottom:4px;
    background-color:#A7C942;
    color:#fff;
}
#Table tr.alt td {
    color:#000;
    background-color:#EAF2D3;
}

JavaScript

var count_2 = 5;

$(document).ready(function () {

    $('#btnAdd').click(function () {
        count_2 = count_2 + 2;
        $('#Table tr:last').after('<tr><td>' + 
            '<p class=\"null_temp\">' +
            '<input type=\"text\" name=\"temp' + count_2 + '\" id=\"temp' + count_2 + '\" placeholder=\"Time\" size=\"10\" maxlength=\"8\" value=\"\" class=\"total_time_regex\" onblur=\"myFunction()\" />' +
            '</td></tr>');
        
        $('.total_time_regex').inputmask('Regex', {             
			regex: "^([-][0-9]{1,4}[.][0-5][0-9])|([0-9]{1,4}[.][0-5][0-9])$"
		});
    });
		
});

        $('.total_time_regex').inputmask('Regex', {             
			regex: "^([-][0-9]{1,4}[.][0-5][0-9])|([0-9]{1,4}[.][0-5][0-9])$"
		});