I would not recommend to use two different style sheets for this. Now a days mobiles, tabs and laptops are having many types of screen sizes. If you decide to handle that many resolutions you have to write that many style sheets. It is inconvenient to handle and also increase your page requests.
That's why professionals recommend to write media queries inside single style sheet. Like this
@media only screen and (min-width : 320px) and (max-width : 480px) {
/* mobile Styles */
}
@media only screen and (min-width : 481px) and (max-width : 800px) {
/*Tab Styles */
}
@media only screen and (min-width : 801px) and (max-width : 1024px) {
/*Desktops Styles */
}
Check it out this link
http://waybloggy.blogspot.com/2014/09/components-required-for-responsive-web.html[
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