I don't know about targeting iOS as a whole, but to target iOS Safari specifically:
@supports (-webkit-touch-callout: none) {
/* CSS specific to iOS devices */
}
@supports not (-webkit-touch-callout: none) {
/* CSS for other than iOS devices */
}
Apparently as of iOS 13 -webkit-overflow-scrolling
no longer responds to @supports
, but -webkit-touch-callout
still does. Of course that could change in the future...