How to automatically scale images when showing content in VIEWS

Hi there,

So, I'm trying to work in the layout of my views page. I had done pretty much everything I wanted, but there is something I can't figure out: I would like to have the images in a smaller size than they are in the actual content, but preserving proportions. I guess there has to be a CSS way to do it, but I haven't been able to find it. Does anyone know how to do it?

Thanks a lot!