CSS for iPhone only

iPhone X

@media only screen 
    and (device-width : 375px) 
    and (device-height : 812px) 
    and (-webkit-device-pixel-ratio : 3) { }

iPhone 8

@media only screen 
    and (device-width : 375px) 
    and (device-height : 667px) 
    and (-webkit-device-pixel-ratio : 2) { }

iPhone 8 Plus

@media only screen 
    and (device-width : 414px) 
    and (device-height : 736px) 
    and (-webkit-device-pixel-ratio : 3) { }