ks-rem-base = 16px

ks-rem( values )
    base = ks-rem-base is a "unit" ? ks-rem-base : 16
    result = null
    for value in values
      	if type( value ) == "unit" && ( unit( value ) == "px" || unit( value ) == "" )
        		value = unit( round( value / base, 3 ), "rem" )
        		if value == "0rem" { value = 0 }
        result = result != null ? result value : value
    result

rem = ks-rem unless ks-no-conflict