<div class="col-xs-2 clearfix">
    <img src="{$Think.config.tpl_src}/bootstrap/img/img-fx.png"
         class="img-responsive pull-right yxg-question-share" alt="Responsive image" id="share_btn">
</div>

#shareit {
    -webkit-user-select: none;
    display: none;
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.85);text-align: center;top: 0;left: 0;z-index: 105;
}
#shareit img { max-width: 100%;}
.arrow {position: absolute; right: 10%;top: 5%;}

$("#share_btn").on("click", function() {
    $("#shareit").show();
});
$("#shareit").on("click", function(){
    $("#shareit").hide();
})