Plan step 36. <x-split-button> renders data-md-split-button and
data-md-size on the pair and data-md-split on its halves. split-button.css
draws SplitButton*Tokens' shape — full outer corners, inner corners that
grow under the finger, the trailing half round while its menu is open —
the narrower leading padding and 48px trailing half at xs and sm, and the
chevron's own size, nudge and turn on the standard scheme. groups.css is
empty and leaves tailwind.css.
The actions browser test follows data-md-split and data-md-button-group,
and gains the owed tests for a connected segment's 48px edge and a
button group's single-required and multi selection.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
