descriptionBuild a dense, data-heavy screen - an analytics console or a trading terminal - with real charts drawn from tokens: candlestick, volume, depth, stacked area, waterfall, scatter, correlation matrix, donut, gauge, sparklines, heatmaps and order books. Use when the request is a dashboard, terminal, monitoring view, data console, or any screen whose job is to show many numbers at once. Covers the layout sequence, the SVG geometry, the accessibility contract per chart type, and the contrast traps that only appear in dark mode. Skill: Data dashboard
Requirements
This skill needs the full UX/UI Agent Skills kit: the gates, the references and
the design-system library. Install it with npx [email protected] init
or as the Claude Code plugin. npx [email protected] add copies the skill folder and
nothing else. Installed that way, this skill runs in guidance-only mode: no gate
runs, so it gives no verdict.
Step 0: is the kit here? Check once:
ls ${CLAUDE_SKILL_DIR}/../../../tokens >/dev/null 2>&1 && echo KIT_OK || echo KIT_MISSING
On KIT_MISSING, open your reply with: "Guidance-only mode: the UX/UI Agent
Skills kit is not installed here, so no gate ran and nothing below is
measured." Then work from this file and general practice, under three rules.
Do not guess or cite the contents of a kit file you could not open. State no
measured number (no contrast ratio, no N/N, no "passes WCAG"): write "not
verified" where one would go. End with a line Skipped (kit not installed):
that names every gate script this file tells you to run, then the install
command above.
A dashboard is the hardest screen to keep honest: it is dense, it is mostly
non-text, and almost every default makes it worse. This is the recipe that
produced ${CLAUDE_SKILL_DIR}/../../../examples/showcase/ and ${CLAUDE_SKILL_DIR}/../../../examples/terminal/, both of which pass every
gate in both themes.
1. Decide the brief before drawing anything
Answer these in one line each, or /grill-me them out of the user:
- Who reads this, and what decision do they make from it? A revenue console
for an operator and a trading desk for a dealer look nothing alike.
- What is the one number that leads? A dashboard without a lead is a wall.
- What is the update cadence? Hourly figures get a "last run" line. Live
figures get a tape and a timestamp per row.
- How dense is honest? A terminal earns 12 panels. A weekly report does not.
2. Layout sequence, not a grid of equal cards
Four equal stat cards is the single loudest tell that nobody designed this.
Compose in bands, each a different shape:
Use a 12-column grid with explicit spans (span 8 / span 4), collapsing to 6
then 1. Never repeat(auto-fit, …) for the primary bands - it produces exactly
the equal-card wall you are avoiding.
3. The chart inventory
All of these are plain inline SVG with viewBox, sized by CSS, filled from
--color-chart-*. No chart library, no runtime dependency.
Generate the geometry, do not hand-place it. Write a small deterministic
script (a seeded walk) that emits the SVG elements, then paste the output in.
Hand-typed coordinates drift and cannot be regenerated.
4. Domain correctness is part of craft
Gates cannot catch a chart that is drawn beautifully and means nothing. Check by
hand:
- A correlation matrix is symmetric and its diagonal is exactly 1. Random
values in both triangles is an instant tell to anyone who reads one for a living.
- A stacked area sums to the total; bands must not cross or leave gaps. The
usual bug is reversing the baseline by index instead of by coordinate, which
shows as dark wedges between bands.
- A waterfall needs connectors, and the closing bar must equal opening plus
the steps.
- Depth rises away from the mid on both sides; it never falls.
- A donut whose segments do not total the whole is a pie chart lying.
5. Accessibility contract, per chart
- Every SVG gets
role="img" plus either aria-label or <title>+<desc>
referenced by aria-labelledby. Say what the chart shows, not that it is a
chart: "Range 182.06 to 200.10, closing at 187.84" beats "price chart".
- Never encode meaning in colour alone. Green with a
+ and an arrow; red with a
-. Up and down also carry a word in the table cell.
- Tables get
<caption> (use .sr-only when the panel header already says it),
scope="col" / scope="row", and aria-sort only if clicking really sorts.
- Sortable headers, range tabs and theme toggles all declare state - so they must
change it on a real click.
verify_interactive.mjs clicks them and checks.
6. The traps that only appear when you measure
Every one of these was found on a screen that looked finished. The first group a
gate caught; the ones marked "no gate sees it" were caught by opening the
screenshot and looking, which is why that step is not optional:
- A chart palette is not a text palette. White initials on
--color-chart-4
measured 2.65:1 in dark. Chart colours are tuned for large filled shapes.
- Success green as text on a raised surface measured 4.43:1 - four
hundredths short of AA. Put the colour on the icon and the sign; keep the text
neutral.
- axe must not run mid-transition. Disable transitions before flipping the
theme, or contrast is sampled while colours are still moving.
- Dense tables do not fit a phone. Drop the column a phone can lose - the
sparkline, the derived value - in a media query, and say so in a comment. Do
not shrink type below the scale.
- Stagger comes from a token:
calc(var(--duration-fast) * 0.6 * n), never a
typed millisecond.
- A grid row stretches its items. Two fields side by side where only one has
a hint: the hint-less control grows to match the taller column and the two
inputs end up different heights. Set
align-content: start on the field and an
explicit block-size on the control. Measure the heights in the render - the
difference is obvious in a screenshot and invisible in the markup.
- The same stretch hits whole panels, and no gate sees it. A row is as tall as
its tallest panel, and the short one packs its content to the top and ends in a
bordered void - a heatmap panel with 130px of nothing under the caption, a right
column that stops two panels short of the map beside it. Every panel in a row
has to say which it is: one child absorbs the slack
(
grid-template-rows:auto minmax(0,1fr), and that child's own tracks go
minmax(<min>,1fr) so its rows grow too), or the rows share it out
(align-content:space-between), or the short column earns another panel.
Screenshot the row and look at the bottom edge of each panel; this never shows
up in the markup.
auto-fit silently drops a column, and no gate sees it. Three gauges in a
panel about 340px wide with minmax(min(100%,7rem),1fr) resolved to two tracks
and orphaned the third beside an empty cell. When the count is fixed and
meaningful, write repeat(3,minmax(0,1fr)) and give narrow widths their own rule.- A category chart needs its categories on the page, and no gate sees it. A
Pareto of five defect types whose names live only in the
aria-label is a row
of anonymous bars to everyone looking at it. Put the labels under the bars -
lay the plot out on an even pitch inside its viewBox so a matching grid of
labels lines up without a second coordinate system.
- An needs a positioned ancestor. Inside a scroller it otherwise
resolves against the initial containing block, lands outside the viewport, and
inflates the document's scroll width by hundreds of pixels.
7. The loop
node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs measure_render.mjs <file> && node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs measure_render.mjs --dark <file>
node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs verify_states.mjs <file> && node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs axe_audit.mjs --dark <file>
node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs verify_responsive.mjs <file> --scale=1.25
node ${CLAUDE_SKILL_DIR}/../../../scripts/gate.mjs verify_interactive.mjs <file>
DS_REQUIRE_BROWSER=1 node ${CLAUDE_SKILL_DIR}/../../../scripts/slop_tells.mjs --strict <file> && DS_REQUIRE_BROWSER=1 node ${CLAUDE_SKILL_DIR}/../../../scripts/taste_audit.mjs --strict <file>
Then screenshot it and look, in both themes, at 1600 and 390 wide. The gates
will pass a chart that is drawn wrong. A correlation matrix that is not
symmetric is 16/16 green and still embarrassing.
Worked references, both gate-verified: ${CLAUDE_SKILL_DIR}/../../../examples/showcase/index.html (revenue
console) and ${CLAUDE_SKILL_DIR}/../../../examples/terminal/index.html (trading desk, ten chart types).
Build a dense, data-heavy screen - an analytics console or a trading terminal - with real charts drawn from tokens: candlestick, volume, depth, stacked area, waterfall, scatter, correlation matrix, do