I want to add a background behind all of my images.
But there is different image sizes.
First I thought I could add backgorund-image to the img tag in CSS, but if there are more than one size, I got problem.
My second thought was to add a pictur with different sizes to all pciture size.
How can I do to add a background-image and deside which size of the picture I will use I would use (in CSS)