Easydiscuss css code conflicting with my banners code

Hello,
I have some responsive banners and since the latest Easydiscuss update the css code

#ed img {

    min-width: 0;

    min-height: 0;

}

is conflicting with the banners code, causing the banner image to be shrinked on mobile devices.
the banner image should look banner-ok screenshot (see also here https://accademiainfinita.it/forum/index
but in easydiscuss pages looks like banner-ko screenshot (see also here https://accademiainfinita.it/blog/12-coscienza/1016-la-notte-buia-dell-anima)

I know that css code is conflicting with this

.responsive-banner .banner-img img {width:260px;

	  height: 100px;

	  max-width: 260px;

	}

but I am not able to find a solution.
I am not even sure if min-width: 0; min-height: 0; is valide css, since there is no px there, google chrome inspector thinks is not valid.

Could you suggest some code to correctly override it and have the banner images look good in easydicuss pages?

Thank you