jquery弹出大图效果

<div class="thumbnail">
  <img src="thumbnail.jpg" alt="Thumbnail" data-large="large.jpg">
</div>
<div class="lightbox" style="display:none;">
  <span class="close-btn">&times;</span>
  <img class="lightbox-content" src="">
</div>

.lightbox {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.8);
  display: flex;
  align-items: center;
  justify-content: center;
}
.lightbox-content {
  max-width: 90%;
  max-height: 90%;
}
.close-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  color: white;
  font-size: 30px;
  cursor: pointer;
}

$(document).ready(function(){
  $('.thumbnail img').click(function(){
    var largeImage = $(this).data('large');
    $('.lightbox-content').attr('src', largeImage);
    $('.lightbox').fadeIn();
  });
  
  $('.close-btn').click(function(){
    $('.lightbox').fadeOut();
  });
});