Just CSS. Absolutely NO jQuery/javascript or any other programming language.

The previous slideshow updated to allow for images in both landscape and portrait orientation.

I have also altered the CSS to make it even easier to update when using any number of images.

For this demonstration I have used 9 images with a show time of 4s and a slide time of 1s.

The only calculation necessary is the @keyframes slide and I have commented this in the stylesheet. It is a pity that CSS variables are not allowed in @keyframes percentage values.

The stylesheet for this demonstration is in the page head, but if you use this, please keep my copyright comment with the stylesheet.