Different layout in different breakpoint

How to create different layout in 1 single website, but it in the different breakpoints, e.g i want to create some of pop up in desktop version to inform user the website only can access in mobile version, but it cant appear in mobile version, how to create this?

thankyou


Here is my site Read-Only: [LINK][1]

Create variations of those elements.
On your desktop-targeted version, assign a global class DesktopOnly
On the mobile-targeted, assign MobileOnly

Then show/hide those classes at the appropriate breakpoints.

e.g. DesktopOnly might be visible at desktop & tablet, but hidden at mobile bps.
MobileOnly might be hidden at desktop & tablet, but visible at mobile bps.