Frontend Design

This skill guides creation of product-specific, production-grade interfaces. Distinctive means the product has a clear point of view, not that the screen is busy. Implement real working code with strong product judgment and excellent accessibility.

The user may ask for a component, page, full app, dashboard, marketing surface, or restyle. Before coding, understand the audience and pick a direction that fits the product instead of defaulting to generic SaaS polish.

Design Thinking

Before coding, decide:

• Job: What is the one thing a repeat user came here to do?
• Audience and mode: Who uses it, how often, and is this operate, read, persuade, or experience?
• Next decision: What must the user understand or choose next?
• World: What existing product system, domain convention, or deliberate visual direction makes this feel authored for this product?

Write that contract in one line before coding: <mode> / <user> / <job> / <next action>.

If the surface has two primary jobs, split the route, step, or state. Do not solve an information-architecture problem with more cards, tabs, helper copy, or buttons. Then implement the smallest cohesive, accessible, responsive surface that proves the contract.

The first-viewport budget

The default state is a calm starting point, not a catalog of everything the feature can do. It should show only:

• where the user is and the current state;
• the content or input needed for the current job;
• for an actionable job, one obvious next action; for a read-only, overview, monitoring, or experience surface, the next decision or focal result.

On actionable surfaces, use one primary action and at most two visible secondary actions. Put rare, advanced, destructive, diagnostic, history, and provider controls in a menu, disclosure, focused dialog, or later step. If a task has more than four visible choices, group or stage them before styling it. If setup, results, feedback, history, and advanced configuration all appear together, the information architecture is wrong - separate the states.

Prefer one visible input group for one job. If several fields are genuinely required, keep them in one focused form or stage them; do not expose separate setup, feedback, and configuration forms on the same default surface.

Every visible element must earn one of four jobs: orient, show work/state, provide required input, or enable the next decision. Remove or disclose anything else. More visible UI is not more capability; routes, actions, menus, keyboard commands, and the agent surface can preserve capability without competing in the first viewport.

Do not add a new input, button, icon, badge, card, or sentence merely because a capability exists. First ask whether an existing row action, menu, composer, agent handoff, or progressive disclosure already owns it. Default to no icon when text is clear; use an icon only when it adds recognition or saves space.

When a screenshot feels busy, delete or defer elements before changing color, radius, shadow, or typography. Whitespace is a valid outcome. A focused tool is better than a miniature control panel.

Visual Direction Contract

For a new app or an explicit visual redesign, define its product mode, audience, visual world, palette family, type treatment, composition, shape language, and anti-references in DESIGN.md. Read references/visual-direction.md for the vocabulary. For a routine screen or cleanup, do not invent a mood-board exercise: inspect the incumbent tokens and components, choose one fitting direction, and get back to the user's job.

Preserve an existing brand system and component library. When no brand exists, choose a deliberate direction based on the domain and compare sibling apps before selecting its accent family. Shared behavior and semantic token names stay consistent; visual variation is a reasoned product choice, not a demand to make every screen novel.

Interaction Responsiveness

Use the Nielsen response-time limits, Google RAIL, and the Doherty threshold as product defaults:

• Make every interaction produce visible feedback immediately, targeting a response within 100 ms so it feels instantaneous. Keep input handling under 50 ms where possible so the browser can paint that response in time.
• If the operation cannot finish within 100 ms, show local or optimistic state, a focused loading/progress state, or a clear working state before then and no later than 400 ms. Never wait for a network round-trip before acknowledging the interaction; reconcile success or roll back on failure.
• Keep ordinary view and navigation changes within 1 second. Work that takes longer needs visible progress and an interruption or cancellation path when the operation supports one.

Default Surface Density

This is the most repeated correction in this repo, tracked as text-heavy-ui in node scripts/agent-friction-report.mjs. Every item below has been asked for by name more than once, usually right after a previous surface was corrected for the same thing. So treat the list as the default shape you apply, not a tradeoff you weigh per surface. If the user wants one of these, they will ask.

Density comes from useful data, not from chrome. A table, inbox, canvas, or editor may be information-dense while its controls stay quiet. Never translate "operational" or "dense" into more cards, buttons, icons, inputs, or visible configuration. If the user came to complete one task, a focused surface with empty space is the correct default.

Keep on-screen text and badging minimal: show the shortest label needed for the next action, remove decorative or duplicate status chips, and put context in a tooltip or progressive disclosure when it is not needed to decide.

Do not add, unless asked:

• A page title that repeats the nav item or route the user just clicked, or a breadcrumb on a page that already has a back arrow.
• A description, subtitle, tagline, or eyebrow under any title — page, card, panel, tab, dialog, settings group, or list row. A surface gets a title or a description, never both.
• A count, stat, or summary strip over content already on screen: "11 apps", "25 results", "0 signals · 0 decisions · 0 runs".
• An About, help, or "what this does" section in settings.
• Helper text under each option in a chooser. The option label carries it.
• A placeholder that restates its own label.

The explanation goes in a tooltip, a Manage popover, a menu, or nowhere. Settings use one shape: a compact row with the label and its current state, one action on the right, and Manage revealing the form once something is configured. Do not spell every input out on the default surface.

Chrome is not content. These rules govern strings you write into JSX. A description the user typed and the app stored is data — render it, and render nothing when it is empty. Never add a || "No description yet." fallback; an empty field is empty, not an opening to explain the feature.

Focused flows

For genuinely sequential setup, prefer one decision per step, a clear progress cue, smart defaults, and advanced detail behind a labeled disclosure. Use a full-screen takeover only when the task deserves uninterrupted focus; use a dialog or inline row for a small task. Do not copy one approved flow onto every surface. Choose the smallest composition that matches the user's actual job.

templates/forms/ is a reference for quiet settings: no repeated page title, breadcrumbs, eyebrows, card descriptions, or form fields before the user asks to create or manage something. User-authored field content is the exception.

Before shipping, verify collapsed, expanded, loading, empty, error, and narrow-width states. The default state fails review when its first viewport carries explanatory paragraphs, several unrelated forms, or controls for another task. guard:no-default-chrome checks the structural half of this on lines your branch adds; it cannot see a sentence you wrote, so the list above is still yours to apply.

Aesthetic Guidelines

• Typography: Use the product's existing type system first. For SaaS and operational apps, make a clear sans-serif hierarchy the default; reserve a serif or editorial face for a deliberate content preview or brand moment, not the whole application shell.
• Color and theme: Use semantic tokens and CSS variables. Avoid one-note palettes, default warm beige/terracotta, and default purple/blue gradients unless the brand demands them. New apps should choose a product-fitting accent family rather than inherit the previous app's color.
• Motion: Prefer purposeful transitions and small state changes. Use CSS transitions/keyframes unless the app already uses a motion library. Never transition-all — list the properties that actually change (e.g. transition-[opacity,transform]). Use the shared easing tokens defined in packages/core/src/styles/agent-native.css instead of hand-typing curves: var(--ease-drawer) (260ms, drawers/app chrome), var(--ease-collapse) (200ms, expand/collapse), var(--ease-out-strong) (snappy entrances) — in Tailwind, ease-[var(--ease-collapse)]. Enter/exit with ease-out, never ease-in. Overlays that zoom in must set the Radix origin var (e.g. origin-[--radix-popover-content-transform-origin]). Animate transform/opacity, not width/height/padding/box-shadow. Gate looping or large-movement animations with motion-reduce:. Command palettes and keyboard-triggered actions get no animation.
• Composition: Match the workflow. Operational apps should be scannable, not necessarily packed; choose a focused flow, list/detail, table, editor, or canvas instead of combining them into equal-weight panels.
• Visual assets: Websites, games, and object-focused pages need real or generated media when images help users understand the subject.
• Responsive fit: Text must not overflow buttons, cards, tabs, sidebars, or fixed-format tools. Use stable dimensions for boards, grids, toolbars, and counters.

Avoid convergence by choosing with purpose. A named direction is useful for a new or explicitly redesigned surface, not as ceremony for every row or dialog. Pair a reference with the reason it fits, then commit to one direction. Only deal multiple visual worlds when the brief is genuinely open and the choice is worth the cost. Never average several directions into extra decoration.

Agent-Native UI Rules

• Agent-Native apps use React and Vite. The default adapter uses Tailwind CSS, shadcn/ui, and @tabler/icons-react, but an app may register a different company design system in app/design-system.ts.
• Use the app's design-system seam for standard UI. Inspect app/design-system.ts, ToolkitProvider, and the local UI adapter directory before choosing a primitive. Use shadcn primitives when they are the active adapter; use the registered company components when they are not.
• When touching shadcn/ui components, also read shadcn-ui if it exists. That skill covers components.json, CLI docs, component composition, theming, and registry workflows.
• Check app/components/ui/ before importing a shadcn component. If a primitive is missing, add it from the app root with pnpm dlx shadcn@latest add <component>, then review the generated file.
• Pages, routes, and domain components must import controls through the app's local adapter path, usually @/components/ui/*. Never import @agent-native/toolkit/ui/* directly in app product code.
• Toolkit/Core feature presentation flows through the semantic components from @agent-native/toolkit/design-system. Their props express intent, emphasis, size, controlled values, and behavior; they do not require Tailwind, CVA, or className.
• For deeper feature customization, consume the feature-level headless controller through its product render slot. The same controller must power the default and custom views. Eject the smallest supported unit only after tokens, semantic components, controllers, and slots are insufficient.
• Do not build custom dropdowns, menus, popovers, modals, or confirmations with manual absolute positioning and click-outside effects.
• Never use browser dialogs (window.alert, window.confirm, window.prompt). Use AlertDialog, Dialog, or app-specific confirmation UI.
• Use Tabler icons for all first-party UI icons. Do not add Lucide, Heroicons, inline SVG icon sets, or emoji icons.
• Never guess a Tabler icon name. Names like IconPartyPopper or IconConfettiCannon feel plausible but don't exist and crash Vite with a "Named export not found" error. Before importing an icon you haven't used elsewhere in this app, confirm it exists by grepping node_modules/@tabler/icons-react/dist/tabler-icons-react.d.ts (or the package's icon list) for the exact name, and pick the closest real match if your first guess isn't there.
• Keep inline help/info glyphs next to labels at size-3 (12px) or smaller than the adjacent text. Preserve a larger hit area on the trigger, not the glyph. Use guard:allow-large-help-icon only for deliberate heading documentation or menu action exceptions. Do not add help glyphs to every row; use one contextual explanation where it is needed.
• Use useActionQuery and useActionMutation from @agent-native/core/client for action-backed UI. Standard CRUD should go through actions, not custom /api/ routes.
• Keep UI optimistic where possible: update cache and navigation immediately, then reconcile or roll back on mutation result.
• Custom styles belong in Tailwind classes, component CSS, or the existing global CSS theme file; avoid inline styles.

Agent Surface And Page Boundaries

• Treat the domain UI and the agent as two coordinated surfaces. The domain page should make the repeatable job fast; the agent should handle judgment, exploration, and actions that benefit from conversation.
• Keep domain work on a named domain route such as /automations, /block, or /workflow. Preserve the starter's full-page chat route (/ or /chat/*) when it exists; do not replace it with a domain form while leaving the shell configured as if it were chat.
• Use the existing right AgentSidebar for contextual AI when the app has one and the task benefits from judgment. A button that sends work to sendToAgentChat must open or focus that sidebar and leave the user on the current domain surface. Do not add a second prompt box or a sidebar merely to make AI visible. Use full-page chat for chat-first work, not as a hidden transport for a domain button.
• Keep the left navigation domain-specific. A page called Automations, Block time, or Create deck should not be nested under a generic Chat item; Chat is its own destination and the right rail is the contextual assistant.
• Never use sparkle, wand, magic, robot, or similar decorative AI icons. Use a familiar message, assistant, or neutral action icon only when it improves recognition; plain text is preferred when it is clearer. An icon-only control needs a tooltip and accessible name.
• When an AgentSidebar exists, give the drawer a quiet but intentional boundary: a subtle surface shift, divider, or both. The sidebar and domain page should not read as one undifferentiated slab, and the treatment should remain calm when the drawer opens or closes.
• Treat an AI-labeled action as a contract. Buttons named Ask agent, Review with agent, Refine, Generate with AI, or similar must call sendToAgentChat with bounded context, openSidebar: true, and the intended submit mode. Prefer one contextual handoff over a row of AI buttons. A deterministic local action is useful, but label it local, preview, or analyze rather than implying it invoked an agent.

Product Surface Review

Before shipping a new app or a substantial redesign, review the surface as an operator would use it repeatedly:

• Name the one primary job and point to the one next action. If either is unclear, fix the structure before styling.
• Mark every visible element as orientation, content/state, input, or next action. Delete or disclose anything without a job.
• Check that there is one primary action, no more than two visible secondary actions, and no decision point with more than four ungrouped choices.
• Remove generic hero copy, feature tours, repeated helper text, nested cards, status-chip soup, decorative icons, and controls for another task.
• Put optional inputs, provider choices, diagnostics, long explanations, history, and secondary actions behind the smallest discoverable disclosure.
• Match the composition to the workflow: focused steps for sequential work, list/detail for inspection, tables for comparison, and canvas/editor space for direct manipulation. Do not combine them as equal-weight blocks.
• Check realistic desktop and narrow-width content in the default, expanded, loading, empty, error, and success states. If it feels like documentation or a control panel instead of a tool, subtract before restyling.

shadcn/ui Design Rules

• Use built-in component variants first (variant, size) before overriding classes.
• Use semantic tokens (bg-background, text-muted-foreground, border-border, bg-primary) instead of raw Tailwind colors for app chrome and reusable components.
• Use gap-* in flex/grid layouts instead of space-x-* or space-y-*.
• Use size-* when width and height are equal, and truncate instead of spelling out overflow/ellipsis/nowrap.
• Use cn() from the local utils alias for conditional classes.
• Dialog, Sheet, Drawer, and AlertDialog content must have an accessible title. Use sr-only only when the visible design already communicates the title.
• Put menu/list items inside their group primitives: SelectGroup, DropdownMenuGroup, CommandGroup, and equivalents.
• Compose cards from CardHeader, CardTitle, CardContent, and CardFooter. Do not add CardDescription, and do not hand-roll a muted <p> under a CardTitle — a card gets a title or a description, never both.
• Use ToggleGroup for small option sets, Switch for binary settings, Checkbox for multi-select, RadioGroup for one-of-many, and Slider/inputs for numeric values.
• For forms, prefer the app's existing shadcn form pattern. If newer Field, FieldGroup, or InputGroup primitives are installed or appropriate to add, use them instead of raw layout divs.
• Page and section data loading uses layout-matching Skeleton geometry. Do not show generic "Loading..." text for content loads; reserve Spinner for brief mutations, uploads, and progress actions. Use the app's existing loading primitive when it is a genuine design-system adapter. Empty states should communicate the state and offer the appropriate next step or small set of choices.

Anti-Patterns

Avoid patterns that add visual noise, obscure state, or compete with the user's task without a clear product reason:

• Generic AI aesthetics: purple gradients, glassy cards everywhere, vague sparkle language, decorative blobs, and context-free hero sections.
• Custom reimplementations of shadcn primitives.
• Raw color overrides on shared components when semantic tokens or variants would work.
• New always-visible controls for rare actions when a contextual surface would preserve discoverability and reduce noise.
• Full-width banners, persistent helper rows, decorative cards, or explanatory chrome for status that could be communicated more clearly with less weight.
• Dropping a label, focus state, hit target, accessible name, or recovery path in the name of minimalism. Defer complexity freely; never defer the ability to operate the control.
• UI cards nested inside other cards.
• Text or icons that resize or shift fixed-format UI on hover/loading.

Verification

Match verification effort to the size of the change. For one component, one form, one page, or a restyle, run the app's existing checks — formatter, pnpm typecheck, existing tests — and stop there.

Escalate to browser verification only when the user asks for it, or when the change is a multi-step user-visible flow that cannot be confirmed any other way. Never author a new Playwright/Puppeteer script, add a browser-automation dependency, or stand up an e2e harness to check work the user did not ask you to test that way; use an available browser tool, or say what you could not verify.

For substantial frontend work:

1. Run the relevant formatter/checks.
2. Start the dev server when the app needs one.
3. Verify with the available browser tooling at desktop and mobile widths.
4. Check interactive states: hover, focus, loading, empty, error, and destructive confirmations.
5. When registering or changing a company adapter, run @agent-native/toolkit/conformance, including mixed-overlay focus, portalContainer, and z-index stacking checks.
6. For a new app or a visual redesign, review DESIGN.md against the rendered surface and run the anti-slop audit in references/visual-direction.md.

Related Skills

• shadcn-ui — shadcn CLI, component docs, composition rules, theming, and registries
• customizing-agent-native — Design-system registration, feature controllers, product slots, conformance, and ejection
• self-modifying-code — The agent can edit source code to apply design changes
• storing-data — All data lives in SQL; use actions for data access
• actions — useActionQuery/useActionMutation hooks for frontend data fetching