How to Resize Thumbnail Image for blog component on mobile

Hi everyone,

I have setup a blog component for displaying testimonials on my homepage and looking for a way to resize the thumbnail image that displays on mobile.

I used the below code, but it's only changing the size on the desktop not mobile. I'm not a coder, so if anyone could provide some assistance it would be appreciated 🙂 

@media only screen and (max-width: 640px){}
.summary-thumbnail img {  
 border-radius: 50%;
  padding: 0px;
  max-width: 15%;
  margin: auto;}

Here are some screenshots from my live site on desktop & mobile. Site built on 7.0, Five template.

https://www.jambusinesssupportservices.com.au/
 

Thanks
 

You can use this code to Website > Website Tools > Custom CSS

@media screen and (max-width:767px) {
    .summary-thumbnail img {
        max-width: 90% !important;
    }
}