Use CSS3 media queries to adapt your website for mobile

@media only screen and (max-device-width: 1100px) {

     #yourselector {
          parameter: setting;
     } 

}

If you want to display elements ONLY on mobile, add the same code replacing “max-device-width” by “min-device-width”.

Source: https://www.smashingmagazine.com/2010/07/how-to-use-css3-media-queries-to-create-a-mobile-version-of-your-website/