— Page Builder: Mobile Editing
The page builder editor includes 3 different "Views". (for desktop, tablet and mobile). You can make many style-related changes on each view. The default hierarchy means that any style applied for desktop would automatically affect smaller (tablet & mobile) styles. However - you can override it for tablet (which would then also automatically use the same styles for mobile), and also just specifically for mobile.
The video below includes a bunch of examples:
Hiding specific elements on mobile
If you want to hide specific elements on mobile/tablet mode (or the other way around - only show them on mobile and not on desktop or tablet), it's easy to achieve with the page builder.
Each element you drop on the page can have a different "display" property set to it. (Note: if you are familiar with CSS, that's exactly like setting display:none; for a certain element.)
Here's a quick video demonstrating how to toggle certain elements in different screen sizes: