New MembershipChart card sits between the DateTimeline and the section
accordions, rendering whenever Members__current_ or
Member_Goal_for_current_Stage has any historical data.
- Actual member count: smooth leaf-700 polyline with a faint leaf-500
area fill underneath, dots at every measurement, an emphasized dot
on the most recent point with the value labeled inline.
- Goal: dashed clay-600 step line — each goal value is treated as a
target that holds until the next update, then extends flat to the
right edge of the chart. Dots at each update; the most-recent goal
value labeled at the right.
- Y-axis: niceYTicks picks 3–5 round-number ticks (snapped to
1/2/2.5/5/10 × 10^N) spanning [min(0, dataMin), dataMax]; faint
gridlines + tabular-num labels on the left. Anchoring at 0 keeps
growth-from-small-base readable.
- X-axis: reuses generateAxisTicks for adaptive month/year stepping,
matching the timeline above. Today gets a dashed clay vertical
guide when in range.
- Header: title + subtitle + an inline 'NNN of MMM target · X to go'
callout in tabular-nums, color-coded (clay-700 if behind goal,
leaf-700 if above).
- Legend at the bottom with line+dot chips for both series.
Joel Brock
ae4e47025c