UI Design

ui-design preserves the user-visible objective while reimagining the simplest greenfield composition and collapsing local markup, arbitrary styling, and duplicated visual contracts into @epicenter/ui, except where app-specific behavior or a load-bearing interaction earns the custom shape.

The existing screen is evidence, not a structure to reproduce. For Epicenter product apps, @epicenter/ui is the default system. Treat shadcn-svelte as implementation lineage and upstream grounding, not as an app import path.

Canonical Path

1. Name the user-visible objective in one concrete sentence. When the product direction is unsettled, read references/direction-discovery.md before choosing the composition.
2. Read the current and neighboring surfaces. Inventory the workflow, hierarchy, accessibility, important states, and recognizable product intent that matter.
3. Sketch the simplest greenfield composition using the natural anatomy of existing @epicenter/ui primitives.
4. Run the component-system collapse pass below. Refuse exact reproduction of incidental markup, spacing, colors, breakpoints, and one-off states.
5. Implement the whole state surface: loading, empty, error, disabled, pending, selected, and filter-empty where relevant.
6. Verify visible, responsive, and interactive results in the browser.
7. Run UI pre-flight before final handoff or committing the change.

For substantial work, state the design read:

Objective: <what the user accomplishes>.
Greenfield shape: <the simplest natural component-system composition>.
Collapse: <the local structure or styling that disappears>.

Component-System Collapse Pass

Run this for every meaningful UI implementation or review, not only work called a redesign. This is the UI application of asymmetric-wins; load that skill when a candidate refusal needs an explicit product-loss versus deletion-prize decision.

Preserve the product sentence.
Challenge the inherited composition.
Refuse the incidental visual promise.
Delete the local code family.

Inspect every wrapper, class bundle, arbitrary Tailwind value, custom color, locally reconstructed state surface, and primitive override. Ask:

1. Does an existing primitive or variant already own this contract?
2. Can the primitive's natural shape replace the wrapper and its classes?
3. Is the exact local detail load-bearing for comprehension, accessibility, interaction, brand, or required geometry?
4. If it survives, who owns it: the app's product behavior or the shared system?

Implement obvious collapses directly. Ask the user only when the refusal changes workflow, hierarchy, product meaning, brand posture, or a plausibly load-bearing detail.

Keep custom UI app-local only when it owns app-specific behavior or product meaning. Move a stable visual contract into packages/ui when several apps need it or it owns an accessibility or interaction contract.

Human Taste Gate

Ask one focused question when human preference would materially change the visual language, brand posture, primary hierarchy, navigation, density, or the direction of an expressive public surface. Present concrete alternatives and a recommendation. Do not ask about choices settled by the shared system, accessibility, existing product intent, or a mechanical collapse.

Product UI And Expressive Surfaces

Product UI should usually be dense, quiet, and operational. Distinctiveness comes from workflow fit, hierarchy, copy, state design, and purposeful details. Marketing pages, docs entry points, prototypes, and explicitly expressive work can use a stronger visual identity, but still run the collapse pass and keep only details that serve the chosen direction.

References

• Read references/direction-discovery.md when the user wants to co-design, compare directions, or turn a rough UI idea into a buildable surface.
• Read references/comparable-apps.md when the design question depends on category fit or what other apps do.
• Read references/component-system.md for every meaningful Epicenter product UI implementation or review. It owns collapse smells and exceptions, then routes exact component and package mechanics to the authoritative packages/ui guide.
• Read references/anti-slop-tells.md for public, marketing, docs, portfolio-like, or highly polished work where templated output is a material risk.
• Read references/preflight.md before final handoff or committing any visible UI change. Report only failures or intentional exceptions.

Delegation Boundaries

• styling owns CSS, Tailwind, spacing, wrappers, overflow, and scroll traps.
• svelte owns component structure, runes, lifecycle, and state mechanics.
• tanstack-table owns table state, columns, sorting, and row identity.
• writing-voice owns visible interface copy and tone.

For an explicit external standards or accessibility audit, WebFetch the Vercel Web Interface Guidelines and apply them directly, reporting findings as file:line. Fetch them per review rather than caching a copy here, because the upstream rules change and a stale copy would be worse than no copy.

https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md

The design decision and component-system collapse stay here even when another skill owns their implementation mechanics.

Final Output

Report the changed surfaces, browser verification, any material deletion prize, and only the custom shapes or pre-flight exceptions that intentionally remain.