Usually, our pages reference many style files, and the style files set many background images for our pages. But there is a small detail here that is easy to overlook. There are browser differences in the processing of image referer sources.
Typically, our styles and images are structured as follows
After testing IE, Safari and Opera, the style referer source of the b.jpg background image in the a.css style is the main domain name address of the site.
However, our Firefox will change the referer source of the image to the path of the style file, so we need to be extra careful when doing some anti-hotlink processing.
