yeah, you can toggle on view transitions in a swap via an hx-swap option:

https://htmx.org/docs/#view-transitions

for now css transitions are more widely supported though:

https://htmx.org/docs/#css_transitions

I'm using view transitions (have to use Chrome to see it), basically just copy-pasted the example from the htmx site. I'd like to do a sliding-opening animation, but I haven't figured out how to do that yet.