Small CSS bug on Website

General information for the website: Image Gallery
Description of requirements/features: I am using MixItUp.js to handle the filters on my image gallery.

Image padding/margin isn't correct at mobile level and needs resolved.
Extra notes: Hi,

I have a page with a few images on it.

These images can be ordered using filters (MixItup JS). The filters work great.

My issue is, when at mobile level, the images don't appear correctly in the grid. The margin spacing isn't right.

I see why this is happening in my CSS so this *should* be an easy enough fix.

I can provide a link example if you need any clarity - just message me :-)