Generate a random snippet of CSS that assigns value to a property.

        :return: CSS property.

        :Examples:
            'background-color: #f4d3a1'

def css_property(self) -> str:
        """Generate a random snippet of CSS that assigns value to a property.

        :return: CSS property.

        :Examples:
            'background-color: #f4d3a1'
        """
        prop = self.random.choice(list(CSS_PROPERTIES.keys()))
        val = CSS_PROPERTIES[prop]

        if isinstance(val, list):
            val = self.random.choice(val)
        elif val == 'color':
            val = self.__text.hex_color()
        elif val == 'size':
            val = '{}{}'.format(self.random.randint(1, 99),
                                self.random.choice(CSS_SIZE_UNITS))

        return '{}: {}'.format(prop, val)