Make CSSRuleList object from style string.

def parse_style_rules(styles: str) -> CSSRuleList:
    """Make CSSRuleList object from style string."""
    rules = CSSRuleList()
    for m in _style_rule_re.finditer(styles):
        rules.append(CSSStyleRule(m.group(1), parse_style_decl(m.group(2))))
    return rules