100% width for gallery width issue

Hi, After hours of trying. I am still not able to make the gallery width to 100% on smaller devices via custom CSS.
From the setting, there is only a fixed width px option for us. I want to make it 100% width. I cannot… Would you please give a CSS selector to control the width. I Have all options set to be ‘0’ already from the setting panel.

I can not locate the correct selector to unset those min-width or min-height. for either variable product images or a single image gallery.

Thanks…