title: firefox dev tools issue
body: <p>I'm using firebug browser and I've written my media queries for mobile view for my website. I have noticed this weird behaviour when using my dev tools's inspect element to test for different mobile screens eg.iphone, the result of my media query only works when I manuallly adjust the browser with my mouse cursor, when I use the dev tools to select phone options, the result is like toggling different desktop views on mobile. Is this normal, how do I stop this behaviour.</p>
  
  <p><strong>Result without manual adjustment</strong><br>
  <a href="http://prnt.sc/s2qkb0" rel="nofollow noreferrer">http://prnt.sc/s2qkb0</a><br></p>
  
  <p><strong>Result while adjusting browser manually</strong><br>
  <a href="https://prnt.sc/s2qnrr" rel="nofollow noreferrer">https://prnt.sc/s2qnrr</a></p>