How to make css grid responsive in a fluid manner

Hello, been messing around with css grid and to a degree I love it. However its quite frustrating as I am trying to make it responsive it a much more fluid manner. When I look at tutorials all over the web theirs seems to flow naturally. However mine seems to change all over the place. The images seem to go out of flow and nothing is neat about it. Could someone explain what is wrong with my markup please?

My link is

You need to make your images responsive. You can do that by giving your images these attributes


Thank you, so much better. Never thought about actually targetting just the images.