Livery

livery

!checklist init ${CLAUDE_SKILL_DIR} --force

A livery is the coordinated visual identity a fleet wears — one paint-and-color scheme applied so every vessel reads as the same family, never repainted by hand per ship. livery is the visual-craft lens of the surface suite: where the other skills decide what is true (boundaries, source of truth, the four states), livery decides what it looks and feels like — and makes that a system, not a pile of ad-hoc values. Its product is a written visual system: a tokenized color-and-light scale, a modular type scale with its spacing scale, a single-light-source depth model, and a purpose-driven motion language — each committed before components consume it. It runs across gated stages and will not advance past a GATE until the checklist tool clears it — order enforced, substance yours.

The governing fact: a polished interface is values derived from a small system; an amateur one is values picked one at a time. The same #3B82F6 typed in nineteen places, a font-size chosen by nudging until it "looks right", a padding: 13px here and margin-top: 22px there, a box-shadow invented per component, a 200ms transition copied from a tutorial — each is a hand-picked value, and their sum is the visual incoherence the eye reads as "cheap" without being able to name it. The craft is the same subtraction the rest of the suite preaches: define a small system (a few tokens, a scale, one light source, a motion purpose), then derive every concrete value from it. Do that and two things happen — the surface becomes coherent (a thousand values agree because they came from ten), and it becomes evolvable (re-theme, dark-mode, or rebrand by changing the system, not finding-and-replacing the thousand).

This is where the agent era bites:

• The agent picks plausible-but-incoherent values and feels no wrongness. It will emit #2563eb here and #2f6ae0 there, a 1.31 then a 1.27 type ratio, a different gutter per component, four different shadow recipes — each defensible alone, the set visually noisy. It has no nervous system to flinch at 90ms of jank or a 4.2:1 contrast. The values must come from a decided system, not per-call taste.
• The agent reaches for the cheap trick. Dark mode by filter: invert(), depth by one fuzzy box-shadow, "animation" by a default transition: all 0.3s, a rainbow for a data series. Each is the move that looks like the craft and isn't.
• The agent treats motion as decoration. It animates because it can, not because the motion has a job — so transitions fire with no purpose, jank under load by animating layout properties, and ignore prefers-reduced-motion entirely.

Read [references/the-membrane.md](references/the-membrane.md) first — the suite's heart; for livery, lean on the axis the README names load-bearing: the benchmark is a human nervous system, so taste cannot be outsourced (16ms is a fusion threshold, 100ms is "I caused that"). Every gate here is a taste decision the agent cannot make for you; what it can do is enforce the system once you've set it. Load at the start, re-check at every gate.

Speak the user's language. The decisions are the user's — which color system, which type scale, which spacing density, how much depth, what motion is for. Read their fluency and gloss a term on first use (perceptual color / oklch, contrast ratio, type scale / modular ratio, fluid sizing / clamp(), measure / line-length, spacing scale / base unit, elevation / light model, design token, spring vs easing, prefers-reduced-motion). A token system the user can't read is a style imposed, not shared.

The reference library

The depth lives in references/. Open each when a stage sends you there — not all upfront.

• [references/the-membrane.md](references/the-membrane.md) — the heart: the agent-era axes; for livery, the taste-is-load-bearing / nervous-system-benchmark axis is the spine. Load at the start, re-check at every gate.
• [references/color-and-light.md](references/color-and-light.md) — perceptual color (oklch), neutral ramps with a temperature, semantic roles, contrast at design time, dark theme as a re-tuned ramp (not invert), and data-viz scales built for perceptual uniformity + colorblind-safety.
• [references/type.md](references/type.md) — the modular scale and ratio, fluid clamp() sizing, pairing and weight roles, measure and line-height by role, the spacing scale and vertical rhythm derived from the same rem unit, numerics, and the optical tells (display letter-spacing, font-features, metrics-compatible fallbacks with no CLS).
• [references/depth-form-texture.md](references/depth-form-texture.md) — one light model for layered shadows and a tokenized z-scale, concentric radii, intentional gradients/texture without banding, and shape.
• [references/icons-and-imagery.md](references/icons-and-imagery.md) — one coherent icon set (matched stroke/grid/optical size), responsive/art-directed imagery aspect-ratio-boxed against CLS, and when Canvas/WebGL earns its place (with a fallback).
• [references/motion-and-feel.md](references/motion-and-feel.md) — motion-with-a-purpose, spring/physics vs easing-curves, gesture intent and arbitration, the reduced-motion path, compositor-only properties, and masking latency to preserve the causal story.
• [references/css-and-tokens.md](references/css-and-tokens.md) — how the token system lives in the browser: custom properties (theming, @property, scoping, fallbacks), the cascade (@layer, specificity, inheritance), modern CSS (container queries, :has(), nesting, color-mix/relative color), the deep-water gotchas (containing-block traps, stacking contexts), and auditing an existing surface — the retrofit inventory that finds where the un-tokenized values hide.
• [references/tokens-across-css-and-js.md](references/tokens-across-css-and-js.md) — when styles live in JS (React inline-style objects, a JS color object, CSS-in-JS): the four ways tokens cross the CSS↔JS boundary, choosing ONE source of truth (var() strings vs a JS token module vs CSS-in-JS theming) so the palette is never maintained in two languages, and the trap that inline styles beat class rules — so an inline style must reference a token too, never a literal.

> The arc is one visual system. Four stages — color · type · form · motion — turn a working-but-styleless build into a coherent surface: color fixes the perceptual palette and light/dark as tokens; type fixes the scale, the spacing scale, and rhythm; form fixes depth, radius, and texture from one light source; motion gives every animation a purpose and physics. livery gates all four; it runs after seaworthy (the four states are built) and its visual system is what lookout later measures as felt performance.

> Greenfield or retrofit? Decide the entry, not a new stage. Most real work is not a blank canvas — it is an existing surface thick with ad-hoc values, and the job is audit-then-retrofit, not invent. The four stages are the same; only the entrance differs. If you are starting clean, walk STAGE 0→3 in order. If a UI already exists, do one pass first: inventory the ad-hoc values — every magic hex, every magic px (spacing especially), every duplicated palette and one-off shadow/radius/duration — and cluster them into the systems the stages will own (color · type · space · form · motion). That inventory is not a deliverable to perfect; it is the raw material each gate consumes — the cluster of forty blues becomes the perceptual ramp STAGE 0 commits, the scatter of font-sizes becomes the modular scale and the scatter of gutters becomes the spacing scale STAGE 1 commits, and so on. The technique for extracting it (where the literals hide across CSS / CSS-in-JS / JS token objects, how to spot the same value duplicated in two languages) is in [references/css-and-tokens.md](references/css-and-tokens.md) under Auditing an existing surface. The taste call stays a gate: for each ad-hoc cluster you still decide what the system should be — the inventory tells you what exists, never what's right. Bring the inventory to STAGE 0 and the gates run unchanged.

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STAGE 0 — Color & light (commit a perceptual color system as tokens)

Open [references/color-and-light.md](references/color-and-light.md). Fix the palette before coloring any component.

• Build in a perceptual space, as tokens. Define the system in oklch (lightness and chroma independent, steps perceptually even), not scattered hex/hsl: a neutral ramp built on purpose (a chosen temperature/hue, not pure gray) plus a small set of semantic roles (surface / text / border / accent / the four feedback states), each a lightness step that holds its contrast relationship in both light and dark.
• Dark is a re-tuned ramp, not invert(). Compress the contrast range, de-saturate and lift accents, signal elevation with a lighter surface rather than a bigger shadow. Check contrast at design time — 4.5:1 body, 3:1 large & UI — not after. Data-viz uses a scale engineered for perceptual uniformity and colorblind-safety, never a hand-picked rainbow. The hard rule: no raw color literal in a component; a value not in the system doesn't ship. And the subtler duplicate isn't a literal — it's the same palette maintained in two languages at once (a CSS custom property and a JS color object), a second source of truth that drifts exactly like any other; that is surface:wellspring's law applied to the design system — the system is itself state, so it gets one source of truth and the other side is derived (var() strings consumed by JS, or a token module that emits the CSS), never two hand-kept copies. When styles live in JS — inline-style objects, a JS color object, CSS-in-JS — pick ONE source and have both languages read it, because inline styles beat class rules, so a literal hidden in an inline style silently wins over every token (see [references/tokens-across-css-and-js.md](references/tokens-across-css-and-js.md)).

GATE — clear before TYPE

1. checklist check color color-system-as-tokens
2. checklist verify color

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STAGE 1 — Type & space (a modular scale and a spacing scale, both rhythm — as tokens)

Open [references/type.md](references/type.md). The thing most responsible for "looks designed" or "looks like a draft" — and the spacing scale that rides on the same rhythm.

• A scale, not sizes. Choose a modular ratio (≈1.2 for dense UI → 1.333 for editorial), express it fluidly with clamp() so it breathes between breakpoints without a media-query cascade, and reference scale steps from components — never magic px. Pair deliberately (or pick one strong family) and name each weight's role.
• Rhythm and the optical tells. Hold measure to ~45–75ch on running text; set line-height by role (tight on display, ~1.5 on body); keep a consistent vertical rhythm. Handle numerics (tabular-nums for data). Address the details that separate pro from amateur: negative letter-spacing on large display, font-feature-settings the face offers, and a metrics-compatible fallback stack so a late webfont causes no layout shift.
• Spacing is the same rhythm, gated separately. Pick one base unit and derive a spacing scale (a small geometric/4–8px-step set: xs…3xl) — every gap, padding, and margin references a step, never a magic px. It is the same rem-based rhythm the type scale rides on, so vertical rhythm and the spacing scale agree. Choose a density (compact data UI vs airy marketing) and let the scale, not the eye, set the values. This is the single most pervasive ad-hoc tell: padding: 13px, margin-top: 22px, a different gutter per component.

GATE — clear before FORM

1. checklist check type type-scale-and-rhythm-systematized
2. checklist check type spacing-scale-systematized
3. checklist verify type

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STAGE 2 — Depth, form & texture (one light source, tokenized)

Open [references/depth-form-texture.md](references/depth-form-texture.md). Depth is where invented values show up most.

• One light model. Every shadow shares a single light direction and is layered (ambient + direct, umbra/penumbra), never a lone fuzzy box-shadow; elevation maps to a tokenized z-scale (resting / raised / overlay / modal), not ad-hoc blur. Radii tokenized and concentric (inner = outer − padding) so nested corners look intentional.
• Texture, icons, imagery with intent. Gradients/texture only with a job (depth, focus, brand) and banding-free (perceptual interpolation / dithering). Icons from one set with matched stroke-width, grid, and optical size. Imagery aspect-ratio-boxed (no CLS), responsive/art-directed, with a deliberate loading + placeholder strategy. Canvas/WebGL only where the DOM genuinely can't go, always with a fallback. Like color and type: every radius, shadow, and surface is a token.

GATE — clear before MOTION

1. checklist check form depth-and-form-from-one-light-model
2. checklist verify form

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STAGE 3 — Motion & feel (purpose, physics, and a reduced path)

Open [references/motion-and-feel.md](references/motion-and-feel.md). The feel is the product; motion without a job is noise.

• Every animation has a purpose; dynamics come from physics. Map each to a job (orient on state change, show causality/continuity, mask latency, direct attention) — delete the rest. Use spring / mass-damping for interruptible, gesture-driven, or natural motion (a re-triggered animation continues from current velocity, it doesn't jank-restart); use easing curves with short durations (≈150–300ms) for discrete UI transitions — never confuse the two. Scale intensity to the surface: the same purpose taxonomy holds everywhere, but a marketing/brand surface can spend signature, expressive motion where a data/tool/dashboard surface should spend almost none — there, motion earns its place only as orientation and causality (state change, what-just-happened, masking latency), runs crisp and short, and a re-fire under streaming data must never restart or distract. The taxonomy is the constant; the budget is set by what the surface is for.
• Non-negotiables. Gesture interactions arbitrate intent (scroll-vs-drag, nested-gesture conflicts, Pointer Events not mouse-only). A real prefers-reduced-motion path (re-tuned, not just stripped). Compositor-only properties (transform/opacity — never animate layout/paint), 60fps held under load. Mask latency so the user's causal story holds — their action visibly, immediately causes the result.

FINAL GATE

1. checklist check motion motion-has-purpose-physics-and-a-reduced-path
2. checklist verify motion
3. checklist show — confirm all four stages passed.
4. checklist done — clear this run's state.

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The thread through all of it

livery is the suite's visual conscience — the place the README's claim that taste is load-bearing finally gets a gate. It runs after seaworthy has built the four states, and its system is what lookout later measures as felt performance and what bulwark must keep from drifting at 1→N. The through-line is the suite's own — push correctness into structure — applied to looks: a value derived from a system can't drift the way a hand-picked one can, so coherence becomes structural rather than maintained by vigilance. The line that keeps livery honest inside a suite that says "the correct isn't in a document": **the document holds the encodable technique (how oklch works, how a spring is tuned, how tokens cross into JS); the taste — which palette, which scale, which density, what the motion is for — stays a gate the user clears.** Blur that line and the skill becomes a recipe book; hold it and it stays a lens.

Anti-patterns (use as a pre-flight checklist)

• Magic values — the same color/size/radius/dura

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Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: IamK77
• Source: IamK77/Skill
• License: Apache-2.0
• Homepage: https://www.npmjs.com/package/@iamk77/skill-checklist

Install and usage instructions live in the source repository linked above.