Avenue mobile thumbnail per row change?

Hi, I am wondering if anybody have same issue with me and if solved?

I am using Avenue template, and tried to change 1 thumbnail per row only on mobile, I am currently have 2 thumbnails per row on desktop version.

Please help! Thanks in advance.

You can use custom code to handle

Can you share link to your site?

I'm looking to do the exact same thing! 

Add to Home > Design > Custom CSS

@media screen and (max-width:750px) {
.thumbnail-layout-basic-grid #projectThumbs .project {
    width: 100%;
    margin-left: 0;
    margin-right: 0;
}
}