问题
I have some very weird issue with firefox while rendering background-images. I'm not sure if it's a firefox bug or simply my fault.
Every time I open my project site in firefox all background images are loaded and displayed correctly. After I switch to another tab and switch back after a while all background images disappeared. I checked the network analysis tab in the developer tools and all files are loaded correctly. Also in some situations parts of the images appear after I select some text over it. After parts of a second all the images show up. So I assume it's a rendering bug in firefox.
My images are implemented like:
background-image:url("path/to/image.png");
background-size:cover;
background-position:center center;
Is there a workaround for that bug? Is that even a bug? Can anyone confirm that? I searched the web and I couldn't find anything...
来源：https://stackoverflow.com/questions/42366232/firefox-background-image-disappear-after-switching-tabs