In my VF page I am using lightningStyleSheets=true attribute to make it look like lightning experience. There also is a layover in the same page, which shows up on a button click and looks like a pop-up. This popup behavior is accomplished using the method described in the best answer at: https://developer.salesforce.com/forums/?id=906F000000097X9IAI
However as far as responsiveness, the main VF page is responsive, due to lightningStyleSheets=true attribute setting, but the layover is not responsive. How can this be achieved? The layover is using it's own style sheet to get it's layover nature, is that causing the problem? Any suggestions?