templates/wtf4_login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style type="text/css">
        .hot{
            background-color: cadetblue;
        }
    </style>
</head>
<body>
    <form action="/login/" method="post">
        <table>
            <tr>
                <td>{{ form.uname.label}}</td>
                <td>{{ form.uname(class='hot')}}</td>
            </tr>
            <tr>
                <td> {{ form.age.label}}</td>
                <td>{{ form.age()}}</td>
            </tr>
            <tr>
                <td> {{ form.remember.label}}</td>
                <td>{{ form.remember()}}</td>
            </tr>
            <tr>
                <td>{{ form.address.label}}</td>
                <td>{{ form.address()}}</td>
            </tr>
            <tr>
                <td></td>
                <td></td>
            </tr>
        </table>
    </form>
</body>
</html>