jQuery弹出框未关闭

你打错了…

This -> jquery('[data-popup="' + targeted_popup_class + '"]').fadeOut(3);

应该是jQuery而不是jquery。如果有什么地方不像预期的那样工作，不要犹豫，看看控制台日志。

jQuery(function() {
    //----- OPEN
    jQuery('[data-popup-open]').on('click', function(e)  {
        var targeted_popup_class = jQuery(this).attr('data-popup-open');
        jQuery('[data-popup="' + targeted_popup_class + '"]').fadeIn(350);
        e.preventDefault();
    });
    //----- CLOSE
    jQuery('[data-popup-close]').on('click', function(e)  {
        var targeted_popup_class = jQuery(this).attr('data-popup-close');
        jQuery('[data-popup="' + targeted_popup_class + '"]').fadeOut(3);
        e.preventDefault();
    });
});

/* Outer */
.popup {
    width:100%;
    height:100%;
    display:none;
    position:fixed;
    top:0px;
    left:0px;
    background:rgba(0,0,0,0.75);
}
 
/* Inner */
.popup-inner {
    max-width:700px;
    width:90%;
    padding:40px;
    position:absolute;
    top:50%;
    left:50%;
    -webkit-transform:translate(-50%, -50%);
    transform:translate(-50%, -50%);
    box-shadow:0px 2px 6px rgba(0,0,0,1);
    border-radius:3px;
    background:#fff;
}

/* Close Button */
.popup-close {
    width:30px;
    height:30px;
    padding-top:4px;
    display:inline-block;
    position:absolute;
    top:0px;
    right:0px;
    transition:ease 0.25s all;
    -webkit-transform:translate(50%, -50%);
    transform:translate(50%, -50%);
    border-radius:1000px;
    background:rgba(0,0,0,0.8);
    font-family:Arial, Sans-Serif;
    font-size:20px;
    text-align:center;
    line-height:100%;
    color:#fff;
}

.popup-close:hover {
    -webkit-transform:translate(50%, -50%) rotate(180deg);
    transform:translate(50%, -50%) rotate(180deg);
    background:rgba(0,0,0,1);
    text-decoration:none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<a class="btn" data-popup-open="popup-1" href="#">Open Popup #1</a>
 
<div class="popup" data-popup="popup-1">
    <div class="popup-inner">
        <h2>Have some feedback?</h2>
        <p>Use the feedback box below if you have a question, comment or general feedback.</p>
        <p><a data-popup-close="popup-1" href="#">Close</a></p>
        <a class="popup-close" data-popup-close="popup-1" href="#">x</a>
    </div>
</div>