Files
chart-sins/README.md
T
Claude a3ab9f8a79 Restyle on the Carbon Design System
Adopt Carbon at the design-token level (the component libraries ship JS and
target app UIs; this is a static content site):

- IBM Plex Sans/Mono, self-hosted via @fontsource (no external requests)
- Carbon color tokens + layered White / Gray 100 themes
- 8px spacing scale, productive/expressive type, motion tokens, square
  geometry, 2px focus ring
- UI-shell header, tile grid, Carbon tags, geometric severity meter,
  breadcrumb, colophon crediting Carbon
- Charts themed with IBM Plex + Carbon's data-visualization palette
  (validated colorblind-safe/contrast) on a fixed light canvas so the
  build-time SVG stays legible in both themes

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XPEvmMbac2fCvKXpQcovj8
2026-08-05 12:41:00 +00:00

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Markdown

# Chart Sins
A catalogue of data-visualization sins — for each one: the chart that misleads,
why it fools the eye, and the honest version that fixes it.
Built with [Astro](https://astro.build) and styled on the
[Carbon Design System](https://carbondesignsystem.com). Charts are authored as
[Vega-Lite](https://vega.github.io/vega-lite/) specs and rendered to **static
SVG at build time**, so pages ship with zero client-side JavaScript.
## Tech stack
| Concern | Choice |
| ---------- | --------------------------------------------------- |
| Framework | Astro 5 (static output) |
| Content | Markdown/MDX via Astro Content Collections |
| Charts | Vega-Lite specs → SVG at build (headless Vega) |
| Design | Carbon Design System — tokens, type scale, spacing, motion, themes |
| Typeface | IBM Plex Sans / Mono (self-hosted via `@fontsource`) |
| Styling | Token-driven CSS (`src/styles/global.css`) |
| Hosting | GitHub Pages (via GitHub Actions) |
| Language | TypeScript |
### On the Carbon adoption
Carbon ships React/web-component libraries built for application UIs and they
ship JavaScript; this is a static content site, so instead of the component
runtime we adopt Carbon at the **design-token level** — its color tokens and
White/Gray-100 themes, the 8px spacing scale, the productive/expressive type
distinction (IBM Plex), motion tokens, square geometry, the focus ring, and
Carbon's **data-visualization palette** for the charts (validated for
colorblind-safety and contrast on the chart surface).
## Project layout
```
src/
├── content.config.ts # typed frontmatter schema for a "sin"
├── content/sins/ # one Markdown file per sin
├── charts/ # Vega-Lite JSON specs (bad + fixed)
├── components/VegaChart.astro # build-time Vega-Lite → SVG renderer
├── layouts/BaseLayout.astro
├── lib/charts.ts # spec lookup + severity helper
├── pages/
│ ├── index.astro # the gallery
│ └── sins/[...slug].astro # a sin's detail page
└── styles/global.css
```
## Adding a new sin
1. Author two Vega-Lite specs in `src/charts/`, e.g.
`my-sin-bad.json` and `my-sin-fixed.json`.
> Omit `$schema`, `config`, and outer `width`/`height` tuning you don't need —
> keep specs focused on the data and encoding.
2. Create `src/content/sins/my-sin.md` with frontmatter:
```yaml
---
title: "My Sin"
summary: "One-line description shown on the gallery."
category: "Misleading Scales"
severity: 3 # 1 (venial) … 5 (mortal)
tags: ["bar chart"]
badChart: "my-sin-bad" # basename in src/charts/, no .json
fixedChart: "my-sin-fixed"
date: 2026-08-05
---
Prose explaining the sin, why it deceives, and the repentance.
```
3. `npm run dev` and check it. The typed schema will flag a mistyped field or a
missing chart spec at build time.
### Making a chart interactive (opt-in)
Charts are static SVG by default. To make one interactive, render it client-side
with `vega-embed` in a small Astro island (`client:visible`) on that page only,
instead of using `<VegaChart>`. This keeps the default fast while allowing
hover/zoom where a specific sin benefits from it.
## Commands
| Command | Action |
| ----------------- | ----------------------------------------- |
| `npm install` | Install dependencies |
| `npm run dev` | Start the dev server at `localhost:4321` |
| `npm run build` | Build the static site to `./dist` |
| `npm run preview` | Preview the production build locally |
## Deployment
Pushing to `main` triggers `.github/workflows/deploy.yml`, which builds the site
and publishes it to GitHub Pages. Enable it once under
**Settings → Pages → Build and deployment → Source: GitHub Actions**.
The site is configured for the project path `https://olehomelchenko.github.io/chart-sins`
(`site` + `base` in `astro.config.mjs`). If you move to a custom domain, set
`site` to it and remove `base`.