隐藏类在特定的屏幕尺寸上不起作用，因为它在767px上显示隐藏类。我不知道为什么会这样？

Question

在此图像屏幕尺寸767px中，所有隐藏的div出现，然后在屏幕下方消失

我不知道发生了什么，只有hidden-xs类会导致此问题。

     

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