Convert size in rem to pixel size based on computedStyle

rem_to_pixels.ts

export function convertRemToPixels(rem: number) {
    if (document?.documentElement) {
        return rem * parseFloat(getComputedStyle(document.documentElement).fontSize);
    } else {
        console.warn('No "document" context, unable to calculate effective pixel size');
        return rem;
    }
}