When loading a page and the field renderer uses "radio button" the button is to small and grey to be seen. When selecting a button, how can the button be made larger to fill the entire circle with black?
I suggest you open the page on a pc and right-click to inspect. I know in chrome you can click the "toggle device mode" button and choose to emulate an iPad. inspect the radio button element CSS to see what custom CSS you need to add to get the desired effect.