Why does Firebug add -moz-* styles when inspecting element CSS?
问题 Whenever I inspect page elements in Firebug, I always see it adding styles such as... -moz-background-clip:border; -moz-background-inline-policy:continuous; -moz-background-origin:padding; ... etc, to the Style box. Why does it do this? 回答1: It isn't Firebug adding those rules but the Gecko rendering engine. They are part of "the default stylesheet". (The default style a particular agent applies before parsing the styles on the page. They have a specificity of 0,0,0,0 which essentially means