index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Form</title>
    <!-- CSS only -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" integrity="sha384-9aIt2nRpC12Uk9gS9baDl411NQApFmC26EwAOH8WgZl5MYYxFfc+NcPb1dKGj7Sk" crossorigin="anonymous">
<link rel="stylesheet" href="/styles.css">
</head>
<body>
    <form action="/" method="post">
        <div class='form-element'>
            <span>ID:</span>
            <input type="text" name="id">
        </div>
        <div class='form-element'>
            <span>First Name:</span>
            <input type="text" name="firstname">
        </div>
        <div class='form-element'>
            <span>Last Name:</span>
            <input type="text" name="lastname">
        </div>
        <div class='form-element'>
            <span>Age:</span>
            <input class="age" type="text" name="age">
        </div>
        <div class='form-element'>
            <span>Email:</span>
            <input class="age" type="email" name="email">
        </div>
        <div class='form-element'>
            <span class='temperature'>Temperature:</span>
            <input class='temperature_input' type="text" name="temperature">
        </div>
        <button type="submit" class='btn btn-primary'>Submit</button>
    </form>
</body>
<!-- JS, Popper.js, and jQuery -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js" integrity="sha384-OgVRvuATP1z7JjHLkuOU7Xw704+h835Lr+6QL9UvYjZE3Ipu6Tp75j7Bh/kR0JKI" crossorigin="anonymous"></script>
</html>