本代码适合在对站点进行pjax的时候使用，直接放在style.css文件末即可。

wpgo_loading.gif

代码一：效果如上图所示，需要引用上图

.pjax_loading {position: fixed;top: 0;left: 0;z-index: 999999;display: none;width: 100%;height: 100%;background-color: #4c4c4c;opacity: 0.3;background: url('images/wpgo_loading.gif') #4c4c4c 50% 50% no-repeat;}

代码二：黑屏后三个点旋转，不需要引用图片

.pjax_loading{position: fixed;top: 0;left: 0;z-index: 999999;display: none;width: 100%;height: 100%;background-color: #2C3E50;opacity: 0.88;background: url('data:image/svg+xml;base64,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') #2C3E50 50% 50% no-repeat;}