1---2name: ux-designer3description: UX/UI design principles for building and critiquing interfaces. Use for accessibility audits (WCAG, EAA), microcopy, forms, navigation, onboarding, internationalization and RTL, voice and AI interfaces, and design systems.4---5
6# UX Designer Skill
7
8Apply the following UX/UI principles when designing or reviewing interfaces.
9
10## When to Apply This Skill
11
12Use this skill when:
13- Designing or reviewing user interfaces, components, and mobile-first layouts
14- Implementing accessibility features or auditing against WCAG 2.2 AA
15- Creating forms, navigation, search, and other interactive elements
16- Writing UI copy and microcopy
17- Planning user research, or building and maintaining design systems
18- Designing collaborative/multiplayer features (presence, real-time editing, sharing, permissions, version history)
19- Building canvas-based or whiteboard applications
20- Designing AI-powered interfaces (chat, copilots, agents, generative UI)
21- Evaluating designs for dark patterns, ethical compliance, and user trust
22- Creating onboarding flows, activation funnels, and first-run experiences
23- Designing notification systems and attention management
24- Building dashboards and data visualizations
25- Internationalizing/localizing UI or adding right-to-left (RTL) language support
26- Designing voice, multimodal, or cross-device input experiences
27
28## Core Design Philosophy
29
30### User-Centered Design
311. **Understand users first** - Research before designing
322. **Reduce cognitive load** - Keep interfaces simple and intuitive
333. **Provide feedback** - Every action should have a visible response
344. **Maintain consistency** - Follow established patterns users expect
355. **Design for accessibility** - Include all users from the start
36
37### Calm & Clarity Over Complexity
38- **Cognitive clarity over sensory richness** - Calm, legible interfaces beat busy,
39 flashy ones. Motion, color, and density should earn their place by aiding
40 understanding, not by impressing.
41- **AI as a respectful copilot, not an autopilot** - Offer AI assistance optionally
42 (sidebars, overlays, suggestions); keep the user in control and every AI action
43 reversible and transparent. See [references/14-ai-ux-patterns.md](references/14-ai-ux-patterns.md).
44- **Responsible adaptation over hyper-personalization** - Adapt to genuine user
45 needs and context; avoid manipulative or opaque personalization.
46- **Depth and judgment over polish** - As UI becomes a commodity, the value is in
47 research, correctness, and knowing when *not* to add something.
48
49### The UX Hierarchy of Needs
501. **Functional** - Does it work?
512. **Reliable** - Is it dependable?
523. **Usable** - Is it easy to use?
534. **Convenient** - Is it frictionless?
545. **Pleasurable** - Is it delightful?
55
56## Core Guidelines
57
58### Before Designing
59- Understand user goals and pain points
60- Review existing patterns in the codebase
61- Consider accessibility requirements (WCAG 2.2 AA)
62- Define success metrics
63
64### Visual Design
65- One dominant element per screen — the primary action outranks all others in size and contrast
66- Consistent typography (16px+ body, 1.3-1.6x heading scale)
67- Sufficient color contrast (4.5:1 for text)
68- Spacing drawn from a single scale (4px or 8px base unit)
69
70### Interaction Design
71- Touch targets minimum 44×44px (iOS) / 48×48dp (Android)
72- Important actions in thumb-friendly zones (bottom/center on mobile)
73- Every interaction produces a visible response
74- Response appears within 100ms of input
75- Smooth animations (300-500ms duration)
76- Support `prefers-reduced-motion`
77
78### Forms
79- Inline validation (on blur, not during typing)
80- Clear error messages near the field
81- Required fields marked with asterisk (*)
82- Logical field order and grouping
83
84### Navigation
85- Limited top-level items (7±2 rule)
86- Current location always visible
87- Mobile: bottom navigation preferred
88- Consistent navigation across pages
89
90### Accessibility
91- All interactive elements reachable and operable by keyboard
92- Every control has an accessible name and role exposed to screen readers
93- Color not sole conveyor of information
94- Focus states visible
95- Alt text for images
96
97### Collaborative Features
98- Presence indicators (cursors, avatars, typing)
99- Clear conflict prevention/resolution
100- Offline state communication
101- Client-specific undo/redo
102- Permission levels clearly communicated
103
104### Canvas/Spatial Apps
105- Cursor-centered zoom (not screen center)
106- Smart guides and snapping with toggle
107- Minimap for large canvases
108- Full keyboard navigation support
109- Viewport culling for performance
110
111### AI Interfaces
112- AI-generated content clearly labeled
113- Source attribution for AI claims
114- User feedback mechanism (thumbs up/down)
115- Stop/cancel generation control
116- Human override always available
117
118### Onboarding
119- First-run experience guides users to "aha moment"
120- Empty states provide clear next actions
121- Onboarding is skippable and won't re-show
122- Sign-up collects only essential fields
123
124### Notifications
125- Notification severity matches visual treatment
126- Push permission requested in context (not on first visit)
127- Users can control notification preferences per channel
128- Toasts auto-dismiss within 4-8s
129- Toasts carrying an undoable action expose that action as a button
130
131### Ethical Design
132- Accept/reject buttons have equal visual prominence
133- No pre-checked optional consent boxes
134- Cancellation is as easy as subscription
135- No confirmshaming in decline copy
136
137### Internationalization
138- RTL-ready (logical CSS properties, layout verified in `dir="rtl"`)
139- Tolerant of ~30-40% text expansion (no fixed-width labels/buttons)
140- No text baked into images; all strings externalized
141- Locale-aware date/number/currency formatting via `Intl`
142- Pluralization handled with ICU plural rules, not string concatenation
143- Language switcher uses endonyms, not flags
144
145## Decision Trees
146
147### Modal vs. Side Panel vs. Full Page
148
149```
150What is the user doing?
151├── Quick confirmation or simple input (1-3 fields)?
152│ └── → Modal dialog
153├── Viewing/editing details while keeping main context visible?
154│ ├── Content is narrow (form, properties, chat)?
155│ │ └── → Side panel
156│ └── Content needs significant width?
157│ └── → Full-page overlay (with back navigation)
158├── Multi-step workflow or complex form?
159│ ├── Steps are short (2-3 fields each)?
160│ │ └── → Modal with stepper
161│ └── Steps are long or need reference to other content?
162│ └── → Full page with stepper
163└── Creating a new complex entity (document, project)?
164 └── → Full page (dedicated creation flow)
165```
166
167### Notification Type Selection
168
169```
170What needs the user's attention?
171├── Immediate action required?
172│ ├── Blocking (must resolve before continuing)?
173│ │ └── → Modal dialog (confirmation, error recovery)
174│ └── Non-blocking but urgent?
175│ └── → Banner (top of page, persistent until dismissed)
176├── Feedback on a completed action?
177│ ├── Success or low-importance info?
178│ │ └── → Toast (auto-dismiss 4-8s)
179│ └── Warning or error?
180│ └── → Toast with action button (manual dismiss)
181├── Background event (new message, update from others)?
182│ ├── User is in the same context?
183│ │ └── → Badge + subtle inline indicator
184│ └── User is elsewhere in the app?
185│ └── → Badge on nav item + optional push notification
186└── System status (maintenance, connectivity)?
187 └── → Persistent banner (top or bottom of viewport)
188```
189
190## Detailed Documentation
191
192- For core UX principles and heuristics, see [references/01-core-principles.md](references/01-core-principles.md)
193- For Laws of UX quick reference, see [references/02-laws-of-ux.md](references/02-laws-of-ux.md)
194- For WCAG 2.2 accessibility compliance, see [references/03-accessibility.md](references/03-accessibility.md)
195- For visual design patterns, see [references/04-visual-design.md](references/04-visual-design.md)
196- For information architecture, see [references/05-information-architecture.md](references/05-information-architecture.md)
197- For interaction design patterns, see [references/06-interaction-design.md](references/06-interaction-design.md)
198- For form and input design, see [references/07-forms-and-inputs.md](references/07-forms-and-inputs.md)
199- For mobile UX best practices, see [references/08-mobile-ux.md](references/08-mobile-ux.md)
200- For UX writing and microcopy, see [references/09-ux-writing.md](references/09-ux-writing.md)
201- For user research methods, see [references/10-user-research.md](references/10-user-research.md)
202- For design system creation, see [references/11-design-systems.md](references/11-design-systems.md)
203- For collaborative presence, live cursors, and awareness indicators, see [references/12a-presence-awareness.md](references/12a-presence-awareness.md)
204- For conflict resolution, sync, sharing, and offline UX, see [references/12b-conflict-resolution-sync.md](references/12b-conflict-resolution-sync.md)
205- For canvas navigation, zoom, pan, and object manipulation, see [references/13a-canvas-navigation.md](references/13a-canvas-navigation.md)
206- For canvas elements, layers, performance, and whiteboard patterns, see [references/13b-canvas-objects-performance.md](references/13b-canvas-objects-performance.md)
207- For AI and LLM interface design (chat, copilots, agents), see [references/14-ai-ux-patterns.md](references/14-ai-ux-patterns.md)
208- For ethical design and dark pattern avoidance, see [references/15-ethical-design.md](references/15-ethical-design.md)
209- For onboarding flows and user activation, see [references/16-onboarding.md](references/16-onboarding.md)
210- For notification systems and attention management, see [references/17-notifications.md](references/17-notifications.md)
211- For data visualization and dashboard design, see [references/18-data-visualization.md](references/18-data-visualization.md)
212- For search interface design and autocomplete, see [references/19-search-ux.md](references/19-search-ux.md)
213- For emotional design and trust-building patterns, see [references/20-emotional-design.md](references/20-emotional-design.md)
214- For data tables, sortable lists, pagination, and bulk actions, see [references/21-data-tables.md](references/21-data-tables.md)
215- For loading states, skeleton screens, optimistic updates, and perceived performance, see [references/22-performance-ux.md](references/22-performance-ux.md)
216- For internationalization, localization, and RTL design, see [references/23-internationalization.md](references/23-internationalization.md)
217- For voice, multimodal, and cross-device input patterns, see [references/24-voice-and-multimodal.md](references/24-voice-and-multimodal.md)
218
219## Reference Values
220
221### Layout & Typography
222
223| Metric | Value | Context |
224|--------|-------|---------|
225| Touch target | 44-48px | Minimum tappable area |
226| Body text | 16px+ | Minimum readable size |
227| Line height | 1.2-1.45 | Optimal readability |
228| Line length | 50-75 chars | Ideal for reading |
229| Contrast ratio | 4.5:1 | WCAG AA for normal text |
230| Contrast ratio | 3:1 | WCAG AA for large text |
231| Working memory | 7±2 items | Miller's Law |
232| Text expansion | ~30-40% | Translation growth (DE/FI/RU) |
233
234### Interaction & Animation
235
236| Metric | Value | Context |
237|--------|-------|---------|
238| Animation | 300-500ms | Natural feeling duration |
239| Touch feedback | < 100ms | Perceived instant response |
240| Form abandonment | 81% | Users who start but don't finish |
241| Canvas zoom range | 10%-4000% | Typical design tool range |
242| Smart guide snap | 2-8px | Distance before snapping |
243| Canvas render | 60fps | Target during pan/zoom |
244
245### Collaboration
246
247| Metric | Value | Context |
248|--------|-------|---------|
249| Cursor update rate | 50-100ms | Smooth live cursor movement |
250| Cursor label max | 12 chars | Truncate longer usernames |
251| Avatar stack | 3-5 visible | Use "+N" for overflow |
252
253### AI Interfaces
254
255| Metric | Value | Context |
256|--------|-------|---------|
257| AI first token | < 1s | Perceived responsiveness |
258| AI streaming | 30-80 tok/s | Natural reading pace |
259| Copilot accept rate | 25-35% | Suggestion usefulness |
260
261### Engagement Metrics
262
263| Metric | Value | Context |
264|--------|-------|---------|
265| Onboarding completion | > 65% | Checklist finish rate |
266| Time to first value | < 5 min | Sign-up to activation |
267| Toast duration | 4-8s | Auto-dismiss timing |
268| Search success | > 70% | Users finding results |
269| NPS | > 50 | User sentiment |
270
271## Anti-Patterns to Avoid
272
2731. **Dark patterns** - Deceptive UI that tricks users → see [15-ethical-design.md](references/15-ethical-design.md)
2742. **Infinite scroll without context** - No sense of progress → see [21-data-tables.md](references/21-data-tables.md)
2753. **Hidden navigation** - Hamburger menus on desktop → see [05-information-architecture.md](references/05-information-architecture.md)
2764. **Autoplaying media** - Unexpected sound/video → see [03-accessibility.md](references/03-accessibility.md)
2775. **Disabled buttons without explanation** - Confusing blocked states → see [06-interaction-design.md](references/06-interaction-design.md)
2786. **Walls of text** - No visual hierarchy or chunking → see [04-visual-design.md](references/04-visual-design.md)
2797. **Color-only feedback** - Excludes colorblind users → see [03-accessibility.md](references/03-accessibility.md)
2808. **Tiny touch targets** - Frustrating on mobile → see [08-mobile-ux.md](references/08-mobile-ux.md)
2819. **No loading states** - Users think system is broken → see [22-performance-ux.md](references/22-performance-ux.md)
28210. **Popup/modal overuse** - Interrupts user flow → see [06-interaction-design.md](references/06-interaction-design.md)
28311. **No presence indicators** - Users don't know who else is working → see [12a-presence-awareness.md](references/12a-presence-awareness.md)
28412. **Silent sync failures** - Data loss without warning → see [12b-conflict-resolution-sync.md](references/12b-conflict-resolution-sync.md)
28513. **Cursor overload** - Too many live cursors create visual noise → see [12a-presence-awareness.md](references/12a-presence-awareness.md)
28614. **Screen-center zoom** - Disorienting; zoom at cursor instead → see [13a-canvas-navigation.md](references/13a-canvas-navigation.md)
28715. **No offline indication** - Users think they're connected when not → see [12b-conflict-resolution-sync.md](references/12b-conflict-resolution-sync.md)
28816. **Hidden AI** - Users should always know when interacting with AI → see [14-ai-ux-patterns.md](references/14-ai-ux-patterns.md)
28917. **Over-automation** - AI changes applied without user awareness or consent → see [14-ai-ux-patterns.md](references/14-ai-ux-patterns.md)
29018. **No AI undo** - AI-applied changes must be reversible → see [14-ai-ux-patterns.md](references/14-ai-ux-patterns.md)
29119. **Confirmshaming** - Guilt-laden language on decline buttons → see [15-ethical-design.md](references/15-ethical-design.md)
29220. **Asymmetric consent** - Big "Accept" button, tiny "Reject" link → see [15-ethical-design.md](references/15-ethical-design.md)
29321. **Mandatory lengthy tours** - Forcing users through 10+ onboarding steps → see [16-onboarding.md](references/16-onboarding.md)
29422. **Notification carpet bombing** - Every event as a push notification → see [17-notifications.md](references/17-notifications.md)
29523. **Permission on first visit** - Asking for push permission before user sees value → see [17-notifications.md](references/17-notifications.md)
29624. **Hardcoded/untranslatable strings** - Text baked into code/images, fixed-width containers, LTR-only layout → see [23-internationalization.md](references/23-internationalization.md)
29725. **Voice-only flows / hidden mic** - No fallback modality, no recognition feedback, buried voice entry → see [24-voice-and-multimodal.md](references/24-voice-and-multimodal.md)
298
299## Sources
300
301This skill synthesizes best practices from:
302- [Laws of UX](https://lawsofux.com/) - Jon Yablonski
303- [Nielsen Norman Group](https://www.nngroup.com/) - Usability research
304- [WCAG 2.2](https://www.w3.org/TR/WCAG22/) - Accessibility guidelines
305- [Material Design](https://m3.material.io/) - Google's design system
306- [Human Interface Guidelines](https://developer.apple.com/design/) - Apple
307- [Interaction Design Foundation](https://www.interaction-design.org/)
308- [Liveblocks](https://liveblocks.io/) - Real-time collaboration patterns
309- [Figma Engineering Blog](https://www.figma.com/blog/category/engineering/) - Multiplayer & canvas
310- [Ably](https://ably.com/blog/collaborative-ux-best-practices) - Collaborative UX
311- [Google PAIR Guidebook](https://pair.withgoogle.com/guidebook) - AI design patterns
312- [Microsoft HAX Toolkit](https://www.microsoft.com/en-us/haxtoolkit/) - Human-AI interaction
313- [Deceptive Design](https://www.deceptive.design/) - Dark pattern catalog
314- [EU Digital Services Act](https://digital-strategy.ec.europa.eu/en/policies/digital-services-act-package) - Platform regulation
315- [EU Accessibility Act](https://ec.europa.eu/social/main.jsp?catId=1202) - EN 301 549 / WCAG 2.1 AA mandate
316- [W3C Internationalization (i18n) Activity](https://www.w3.org/International/) - i18n/l10n standards
317- [Baymard Institute](https://baymard.com/) - E-commerce UX research
318- [Edward Tufte](https://www.edwardtufte.com/) - Data visualization
319- [ColorBrewer](https://colorbrewer2.org/) - Colorblind-safe palettes
320- [The A11y Project](https://www.a11yproject.com/) - Accessibility community resource
321- [web.dev](https://web.dev/) - Core Web Vitals and performance UX
322- [Smashing Magazine](https://www.smashingmagazine.com/) - Practical UX/UI patterns