`) that owns responsive sizing, title/caption, and the **table-view toggle** (the accessibility twin of every chart). **Any fixed height includes the x-axis band** (plot height + axis labels) so the card never gets a nested vertical scroll; prefer letting the container grow with its content. - **Legend** (toggle-to-isolate, texture-aware swatches) · **Tooltip** · **Axis** · **Data label**. ## Tier 1 — The charts people ask for - **Bar chart** — grouped + stacked, thin-bar default, horizontal + vertical. - **Line chart** — multi-series, soft-fill area variant, accessibility markers. - **Stat tile** — value + delta + optional sparkline (the figure contract). - **Meter / progress track** — same-ramp tracks. ## Tier 2 — Rounding out the kit - **Area chart** (stacked, band-edge = line) · **Sparkline** · **Heatmap** - **Scale legend** (sequential / diverging) · **Chart filters / time range** · **Empty state** ## System tier — becomes the skill - **Six-checks validator** — `scripts/validate_palette.js` (palette validation). - **Theming engine** — snap a customer's ramps to passing values (color-formula.md). - **Chart-type heuristic** — pick the form (choosing-a-form.md). - **Table-view generator** — the WCAG-clean equivalent of any chart. Notes: part-to-whole rides on the stacked bar chart; donut stays deprioritized. Small multiples is a layout pattern over these, not a separate piece. Scatter joins Tier 2 if scatter-heavy surfaces land.