Premium
An RSVP card. Check Going and your avatar drops into the front of the stack with an overshoot, the others shuffle right in a wave, the last one tucks into the overflow chip and +3 rolls to +4.
Also known as: rsvp checkbox avatars, join event facepile, avatar group add me css, attending checkbox animation.
Premium
Everything you see above is live. Basic and Pro include every premium piece, with the HTML and CSS ready to copy, plus the Tailwind version where there is one and Motions in Claude Code on Pro.
--chk-color on the element or a parent.
Currently previewing #3b82f6.--chk-size. Every other dimension is in
em, so the whole thing scales together. Currently previewing 24px.transition or animation
shorthand. Staggered delays are relative, so they keep their rhythm.