I noticed in my logfiles that laptops/desktops seem to be calling my mobile.css
I did a test myself and confirmed this. My site is calling mobile.css when I use an apple/android device and I can see the site how it should be on smaller devices, but I don't see why large devices are also calling my mobile.css and then not using it.
What I have in the head is
<link media="only screen and (max-device-width: 800px)" href="/mobile.css" type="text/css" rel="stylesheet">
I thought this would mean "only load mobile css if you are a small device" whereas it seems to be working "download this but only use it if you are a small device".