ah!

goal is to make: a full width popup picker using summaries and pictures. see if only on sibling can be at once with just css.

image placeholder — a square image.

a landscape video.

kind of as planned

so that works where all <details> elements share the same name property.

some additional ideas.

improved method of setting width.
target surface area of media?
width based on target height?
progress bar on the summary while details is open.
flex shrink to match width of image (variable).
image grows to match width of parent.
visual change on hover.
multimedia, image, videos, audio.
ui to reflect toggling (open / close).
background when open, for text at least.
transition details width when toggled.
improved navigation with mouse.
improved navigation with keyboard.