issue with CSS media queries(scrollbar)

Question

I am having problem with css media query in Firefox. It works correct in Chrome like I made two DIVs and want a scrollbar. If I decrease the screen size of firefox upto 800p

Answer 1

Play safe!

My final strategy is added 20px to the media queries and that is my default white space on the layout.

With one exception: @media (min-width: 320px) At that size a don't leave the 20px white space and include one more rule to solve minor background issues:

html body {
    min-width: 320px;
   }

20px is the scroll bar default width size.

FYI: https://www.sitepoint.com/rwd-scrollbars-is-chrome-better/