RSVP button for Facebook Event using CSS / encoded image

gistfile1.html

<!-- http://tinkerbin.com/jkItQEwh -->

<a href="https://www.facebook.com/events/331218348435" class="fb_rsvp" target="_blank" title="RSVP on Facebook">RSVP</a>

<style type="text/css">
a.fb_rsvp {
    background: #ECEEF5 url(data:image/png;base64,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%3D) no-repeat;
    border: 1px solid #CAD4E7;
    border-radius: 3px 3px 3px 3px;
    display: block;
    float: right;
    height: 18px;
    margin: 3px 3px 3px 10px;
    overflow: hidden;
    padding: 0 2px;
    text-indent: -9999px;
    width: 48px;
}
a.fb_rsvp:hover {
    border-color: #9DACCE;
}
</style>