radio and checkbox appearance difference on chrome and Firefox bowers and safari browser on Ipad and iphone 10 are in small size

(First point) Radio and checkbox appearance difference on chrome and Firefox browsers, and (second point) safari browser on Ipad & iPhone 10 it appears smaller in size. ( third point ) is about the input placeholders appearance on chrome, firefox & safari browsers.

Tried on Chrome windows, firefox windows, safari on Ipad & iPhone 10 Placeholders on chrome upwards, firefox downwards, safari center.