OpenAI dotcom figures

Reproduce the two figure types OpenAI uses in its posts, as self-contained HTML/SVG (no Vega, D3, Mermaid, or build step):

1. Bar charts — grouped or single-series. → see "Bar charts" below.
2. Flow / process diagrams — e.g. the "Quality assurance pipeline". → see "Flow diagrams" below.

Both share one design system: the real OpenAI Sans font (loaded from OpenAI's public CDN), near-black ink #0d0d0d, and a pink accent. The full color palette (6 hues × 5 shades) and token rules are in references/design-spec.md — read it when you need extra hues, more series, or to theme surrounding page elements so everything reads as one system.

Bar charts