Learn how to create a Responsive Image Grid.
Read on how to do it in this link: https://www.w3schools.com/howto/howto_css_image_grid_responsive.asp
Responsive Image Grid
Learn how to create an image gallery that varies between four, two or full-width images, depending on screen size:
Try it yourself here: https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_image_grid_responsive