public function getPixelValue(string $size)
    {
        $value = preg_replace('/[^0-9.-]+/', '', $size);
        $unit = preg_replace('/[^acehimnprtvwx%]/', '', $size);

        // Convert 16px = 1em = 2ex = 12pt = 1pc = 1/6in = 2.54/6cm = 25.4/6mm = 100%
        switch ($unit) {
            case '':
            case 'px':
                return (int) round($value);

                break;

            case 'em':
                return (int) round($value * 16);

                break;

            case 'ex':
                return (int) round($value * 16 / 2);

                break;

            case 'pt':
                return (int) round($value * 16 / 12);

                break;

            case 'pc':
                return (int) round($value * 16);

                break;

            case 'in':
                return (int) round($value * 16 * 6);

                break;

            case 'cm':
                return (int) round($value * 16 / (2.54 / 6));

                break;

            case 'mm':
                return (int) round($value * 16 / (25.4 / 6));

                break;

            case '%':
                return (int) round($value * 16 / 100);

                break;
        }

        return 0;
    }