Images All Resized to Large!

My page was looking right, and then some upgrade, and now all my images are coming in larger. I tried on both mobile and desktop web versions, and the images are enormous. I have many weblinks and features to re-upload and build on the page. Is there a custom CSS code to add to the gallery to resize them all to business card shape and reasonable size?

The page I need help with: [log in to see the link]