It's supposed to be very good on mobile devices. We would appreciate it if a lot of people test it on various devices.
I am testing demo forum in different browsers and it's working good so far, but I can't stand bright white color, so please think about changing it to something different by default and add dark theme switch.
Even current smf forum is using grey-blue color that is much easier on my eyes.
ANother thing I noticed on demo forum is that profile signatures are not visible at all, and I disabled all ad blockers in my browser.