How do I stop the facebook send widget from going off the screen?

Question

It doesn't work on jsfiddle, only localhost due to sandboxed iframes.

CSS Code

.twitter-share-button {
    vertical-align:middle;
}
.return iframe, .return fb-send {
    margin-top: 4px;
}
.returnhere {
    position: absolute;
    right: 15px;
    top: 68px;
}
.return {
    display: inline-block;
    background-color: #3D806B;
    border-radius: 0px 0px 3px 3px;
    color: #DCDCDC;
    font-size: 0.85em;
    height: 30px;
    line-height: 2em;
    padding: 0 5px;
    vertical-align: top;
}
.return iframe, .return fb-send {
    margin-top: 4px;
}
.twitter-share-button {
    vertical-align:middle;
}
.return2 {
    display: inline-block;
    background-color: #3D806B;
    border-radius: 0px 0px 3px 3px;
    color: #DCDCDC;
    font-size: 0.85em;
    height: 30px;
    line-height: 2em;
    padding: 0 5px;
    vertical-align: middle;
}
.return2 iframe, .return2 fb-send {
    margin-top: -3px;
}
.twitter-share-button {
    vertical-align:middle;
}
#u_0_3 {
    background-color: yellow !important;
}

HTML Code

<div id="fb-root"></div>

<div class="returnhere">
    <div class="return"><a href="/tellafriend" rel="shadowbox;width=611;height=453" target="_blank">Invite via email</a>

    </div>
    <div class="return2" style="vertical-align: middle;">
        <div class="fb-send" data-href="http://compesh.com" data-font="trebuchet ms"></div>
    </div>
    <!-- <div class="return" style="vertical-align: middle;"><a href="http://www.facebook.com/sharer.php?u=https://simplesharebuttons.com" target="_blank"><img src="graphics/fbshare.png" alt="Facebook" /></a></div> -->
    <div class="return"><a href="/newdebate">Add a debate</a>

    </div>
    <!-- initialise -->
</div>
<script>
    (function(d, s, id) {
        var js, fjs = d.getElementsByTagName(s)[0];
        if (d.getElementById(id)) return;
        js = d.createElement(s);
        js.id = id;
        js.src = "//connect.facebook.net/en_GB/sdk.js#xfbml=1&version=v2.3&appId=299539706821986";
        fjs.parentNode.insertBefore(js, fjs);
    }(document, 'script', 'facebook-jssdk'));
</script>

I can't style it with CSS.

#u_0_3{
      background-color: yellow !important;
      left: -200px;
}