How Style Twitter popup

I added a Twitter share button into my blog using the below code:

<a class="twitter popup" href="http://twitter.com/share?text=mytext">Tweet Me</a>

and I open it in a popup with:

    <script type="text/javascript">
 $('.popup').click(function(event) {
    var width  = 575,
        height = 400,
        left   = ($(window).width()  - width)  / 2,
        top    = ($(window).height() - height) / 2,
        url    = this.href,
        opts   = 'status=1' +
                 ',width='  + width  +
                 ',height=' + height +
                 ',top='    + top    +
                 ',left='   + left;

    window.open(url, 'twitte', opts);

    return false;
  });</script>

There is a way to style the popup? I want my styled popup with the twitter form in it.