Other values than px do not produce the same result

[viu-x]

I've used your plugin with px values in several projects now without problems and loving it.

In a current project I need rem values and those do not work properly at all.

Assuming a base font size of 16px = 1rem; The following produce totally different results:

:root {
	--design-min: 800;
	--design-max: 1440;

	/* generated values */
	--fv-calc: (100vw - var(--design-min)* 1px) /(var(--design-max) - var(--design-min));
    --2-4rem: clamp(2rem, calc(2rem + 2* var(--fv-calc)), 4rem);
	--32-64: clamp(32px, calc(32px + 32 * var(--fv-calc)), 64px);
}

h1 {
	/* this renders everything perfectly */
	font-size: var(--32-64);

	/* 
	here the lower limit is equal to 32px, but the interpolation up to --design-max and the maximum size do not correspond.
	if I resize my viewport to 5000px wide, then I only get a calculated value of 45.125px. Far away from the desired 64px or 4rem.
	and I think it has to do with the value of --fv-calc which results in a px value but then gets added to a rem value.
	*/
	font-size: var(--2-4rem);
}

For a 100vw = 1920px the value of --fv-calc results in 1.75px. Therefore the value of the calc function inside clamp results in 35.5px.