def css(self):
        """Returns
        -------
        str
            The CSS.
        """
        css_list = [DEFAULT_MARK_CSS]
        for aes in self.aesthetics:
            css_list.extend(get_mark_css(aes, self.values[aes]))
        #print('\n'.join(css_list))
        return '\n'.join(css_list)
Returns
        -------
        str
            The CSS.