Data Dashboard skill

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 ux-ui-agent-skills@3.1.0 init or as the Claude Code plugin. npx skills@1.7.6 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:

Band	Content	Why
1	Hero metric at 3x body size + its own chart, spanning most of the width	The eye lands once
2	Two or three secondary figures, stacked or narrow	Quiet by construction
3	Three different chart shapes side by side (donut, ranked bars, sparklines)	Variety reads as intent
4	A table that really sorts, plus a feed or log	Detail after summary
5	A footer line that ends the page	A page must end on purpose

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.

Chart	Geometry	Use it for
Bar / column	<rect> per bucket, rx for a soft corner	Discrete periods
Candlestick	<line> wick + <rect> body per period, class by up/down	OHLC price
Volume	Bars under the price chart, same x-scale, opacity:.45	Conviction behind a move
Moving average	<polyline> over the candles, 2px, round joins	Trend through noise
Line / sparkline	<polyline>, pathLength="1" for a draw animation	Trend in a cell
Area / stacked area	<path> per band: forward along the top, reverse along the previous baseline, close	Composition over time
Depth	Two cumulative area paths mirrored around the mid	Book liquidity
Waterfall	Floating <rect> per step + dashed connectors between levels	Attribution
Donut	<circle> with stroke-dasharray and rotate() per segment	Share of a whole, 3-5 slices
Radial gauge	Same trick, stroke-linecap:round, 270-degree sweep	One value against a limit
Scatter / bubble	<circle>, radius = third dimension	Two measures plus weight
Correlation matrix	HTML table, cell tint via color-mix	Pairwise relationships
Heatmap	HTML table or <rect> grid, tint by value	Cohorts, calendars
Order book	HTML table with a depth bar per row	Bids and asks

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 .sr-only 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.
• A zero-area element that only has area while it animates reads as content lost under prefers-reduced-motion. Give a radar sweep a wedge, not a 1px line.
• Never reuse a class name across layout and colour. .c4 as both a four-column span and the fourth chart colour painted an entire panel pink.

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).