private function _mergeStyles(array $styleA, array $styleB)
    {
        foreach($styleB as $prop => $val) {
            if(!isset($styleA[$prop])
                || substr(str_replace(" ", "", strtolower($styleA[$prop])), -10) !== "!important")
            {
                $styleA[$prop] = $val;
            }
        }

        return $styleA;
    }