Please, please add a way to preview landing pages on mobile from within the editor! I'm wasting so much time updating the page with custom CSS code, publishing it, waiting 4-5 minutes for it to update, and then looking at it on my phone. I spent 2 hours on this yesterday trying to create some custom CSS code to reduce the padding in my text blocks so it would show up better on mobile. At least half that time was just waiting for the page to update so I could see if the CSS code worked. There is a preview for desktop, now we just need a preview for the mobile size. Thanks!