...a folder or sub-folder is represented by a "manilla-folder" thumbnail with badges showing the quantity of contents.

Click/touch any folder image to proceed further into subfolders.

Orange counters indicate the # of sub-folders; green counters indicate the # of images; both, together, indicate the # of sub-folders and the # of images contained, therein. A thumbnail of every image in the current subfolder is automatically created if it does not already exist, each linking to a larger version in a touch-enabled fancybox 'lightbox'

Once you click/touch an image, you can then navigate through the sub-gallery in any of three ways:

Close the image-preview with the [esc] key, or with the × in the top-right corner

Navigation context (e.g., "breadcrumb trail", "link-back-to", etc.) is interactive at the top of the page

Image processing in Photoshop; graphic design in Affinity Designer

Primary source derived (and extensively modified using BBEdit on a Mac Pro) from Harry Ghazanian's most-excellent folioGallery

I originally used v1.3

Unfortunately, Harry G has suspended development of FolioPages. See: github.com/padabou for more details, and example code

Thanks, Harry

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