1import { PixelRatio, Platform } from 'react-native'; 2 3export function rem(value: number): number | string { 4 if (Platform.OS === 'web') return `${value}rem`; 5 return PixelRatio.getFontScale() * 16 * value; 6} 7 8export function em(value: number): number | string { 9 if (Platform.OS === 'web') return `${value}em`; 10 return rem(value); 11} 12