Not show Style edit in inspect element of empty div or span

Hi, I have problem in inspect element of element. Here i have first screenshot in Chrome (http://i.prntscr.com/MByHTxMcRSGi-KvJizrv5A.png) and here this show style of empty div but in Firefox Nightly, i have latest version 57 (http://prntscr.com/g5ak0x). But in Nightly, this is not showing empty div edit style in inspect element (http://prntscr.com/g5al4e). Please give me solution for this. I am frontend developer and need to check style in inspect element. So for checking style of empty div i have opened the chrome but i like Firefox. So please help me out this (Error, Bug etc). Thanks