Improve the robustness of the CSS parser

    def remove_all(self) -> bool:

        with open(self.filename, encoding='utf-8') as f:

            cleaned = re.sub(r'/\*.*?\*/', '', f.read(), 0, self.flags)

            try:

                content = f.read()

            except UnicodeDecodeError:  # pragma: no cover

                raise ValueError

            cleaned = re.sub(r'/\*.*?\*/', '', content, 0, self.flags)

        with open(self.output_filename, 'w', encoding='utf-8') as f:

            f.write(cleaned)

        return True

    def get_meta(self) -> Dict[str, Any]:

        metadata = {}

        with open(self.filename, encoding='utf-8') as f:

            cssdoc = re.findall(r'/\*(.*?)\*/', f.read(), self.flags)

            try:

                content = f.read()

            except UnicodeDecodeError:  # pragma: no cover

                raise ValueError

        cssdoc = re.findall(r'/\*(.*?)\*/', content, self.flags)

        for match in cssdoc:

            for line in match.splitlines():

                try: