let baseBreakpoint = 20 interface Breakpoints { small: string medium: string large: string extraLarge: string } export let breakpoints = [ ['small', baseBreakpoint], ['medium', baseBreakpoint * 2], ['large', baseBreakpoint * 3], ['extraLarge', baseBreakpoint * 4], ].reduce( (acc, [label, val]): Partial => ({ ...acc, [label]: `${val}em`, }), {}, ) as Breakpoints