index.html

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1" />
        <title>Bad UI</title>
        <link rel="stylesheet" href="style.css">

        <style>
            ul {
                list-style-type: none;
                margin: 0;
                padding: 0;
            }

            li {
                display: block;
                margin: 0 0 10px 0;
                padding: 20px 30px;
                background-color: #444;
                color: #fff;
                text-decoration: none;
                border-radius: 5px;
                border: none;
                box-shadow: none;
            }

            li:hover {
                background-color: #aaa;
            }

            a {
                text-decoration: none;
                color: white;
            }

            @media (max-width: 768px) {
                ul {
                    font-size: 12px;
                }
            }
        </style>
    </head>
    <body>
        <div class="wrapper">
            <ul>
                <li><a href="birthdate_selector.html">Birthdate Selector</a></li>
            </ul>
        </div>
    </body>
</html>