@TigerLily67 Sorry, I didn't explain properly. You need to create two text blocks, one with a background (for the mobile version) and another without a background. Then, with custom code, I'll change it so that the one without a background is visible only on desktop, and the one with a background is visible only on mobile. Just make a duplicate of the text box you have right now and remove its background, which we'll display on desktop.
