One of the reasons I quit developing in C3 and am seriously debating whether I wanna try again is UI issues.
The whole method of scaling and how to handle browser resizing is just a nightmare. The only solution I found for a web based app (and this would probably apply to phone apps as well due to their vast number of sizes) is to manually detect screen sizes, browser sizes, etc and then create a browser.onresize function that rearranges everything on the layout into what you hope is the proper place.
I wish you luck.