I Frontend Design

This skill guides creation of distinctive, production-grade frontend interfaces that avoid generic "AI slop" aesthetics. Implement real working code with exceptional attention to aesthetic details and creative choices.

Synced with upstream impeccable v2.1.1: 2026-04-17

Context Gathering Protocol

Design skills produce generic output without project context. You MUST have confirmed design context before doing any design work.

Required context — every design skill needs at minimum:

• Target audience: Who uses this product and in what context?
• Use cases: What jobs are they trying to get done?
• Brand personality/tone: How should the interface feel?

Individual skills may require additional context — check the skill's preparation section for specifics.

CRITICAL: You cannot infer this context by reading the codebase. Code tells you what was built, not who it's for or what it should feel like. Only the creator can provide this context.

Gathering order:

1. Check current instructions (instant): If your loaded instructions already contain a Design Context section, proceed immediately.
2. Check design/context.md (canonical): Read design/context.md from the project root. If it exists and contains the required prose sections (Users & Purpose, Brand Personality, Aesthetic Direction), proceed. The Design Tokens section may be empty — that's valid.
3. Check .impeccable.md (migration fallback): If design/context.md doesn't exist, check .impeccable.md in the project root. If found and it contains the required context, proceed.
4. Check design/direction.md (migration fallback): If neither of the above exist, check for design/direction.md (exact filename). If found, read it and extract audience, intent, and aesthetic direction from its sections.
5. Run /i-teach-impeccable (REQUIRED): If none of the above sources have context, you MUST run /i-teach-impeccable NOW before doing anything else. Do NOT skip this step. Do NOT attempt to infer context from the codebase instead.

Hard gate: If a context file exists (any of steps 2-4) but is missing required prose sections (Users & Purpose / Users, Brand Personality, Aesthetic Direction), redirect to /i-teach-impeccable with a message identifying what's missing. Do not proceed with incomplete context — a partial file is more dangerous than no file.

Scoping Rule

All i-* skills inherit this default scoping behavior:

• If the user provided a path or component name (e.g., /i-typeset src/components/Header.tsx), scope to that target.
• If the conversation has a clear current focus (a file being discussed, a component just modified), scope to that.
• If scope is ambiguous, STOP and ask:

AskUserQuestion:
  question: "What should I work on?"
  header: "Scope"
  options:
    - label: "Current file"
      description: "The file we're currently looking at"
    - label: "Specific component"
      description: "I'll name the component or path"
    - label: "Whole UI"
      description: "Scan the entire frontend codebase"

Do not guess scope. Operating on the wrong files wastes time and produces irrelevant proposals.

Design Direction

Commit to a BOLD aesthetic direction:

• Purpose: What problem does this interface solve? Who uses it?
• Tone: Pick an extreme: brutally minimal, maximalist chaos, retro-futuristic, organic/natural, luxury/refined, playful/toy-like, editorial/magazine, brutalist/raw, art deco/geometric, soft/pastel, industrial/utilitarian, etc. There are so many flavors to choose from. Use these for inspiration but design one that is true to the aesthetic direction.
• Constraints: Technical requirements (framework, performance, accessibility).
• Differentiation: What makes this UNFORGETTABLE? What's the one thing someone will remember?

CRITICAL: Choose a clear conceptual direction and execute it with precision. Bold maximalism and refined minimalism both work—the key is intentionality, not intensity.

Then implement working code that is:

• Production-grade and functional
• Visually striking and memorable
• Cohesive with a clear aesthetic point-of-view
• Meticulously refined in every detail

Frontend Aesthetics Guidelines

Typography

→ Consult typography reference for OpenType features, web font loading, and the deeper material on scales.

Choose fonts that are beautiful, unique, and interesting. Pair a distinctive display font with a refined body font.

• Use a modular type scale with fluid sizing (clamp) for headings on marketing/content pages. Use fixed rem scales for app UIs and dashboards (no major design system uses fluid type in product UI).
• Use fewer sizes with more contrast. A 5-step scale with at least a 1.25 ratio between steps creates clearer hierarchy than 8 sizes that are 1.1× apart.
• Line-height scales inversely with line length. Narrow columns want tighter leading, wide columns want more. For light text on dark backgrounds, ADD 0.05-0.1 to your normal line-height — light type reads as lighter weight and needs more breathing room.
• Cap line length at ~65-75ch. Body text wider than that is fatiguing.

The model's natural failure mode is "I was told not to use Inter, so I will pick my next favorite font, which becomes the new monoculture." Avoid this by performing the following procedure on every project, in order:

Step 1. Read the brief once. Write down 3 concrete words for the brand voice (e.g., "warm and mechanical and opinionated", "calm and clinical and careful", "fast and dense and unimpressed", "handmade and a little weird"). NOT "modern" or "elegant" — those are dead categories.

Step 2. List the 3 fonts you would normally reach for given those words. Write them down. They are most likely from this list:

Reject every font that appears in the reflex_fonts_to_reject list. They are your training-data defaults and they create monoculture across projects.

Step 3. Browse a font catalog with the 3 brand words in mind. Sources: Google Fonts, Pangram Pangram, Future Fonts, Adobe Fonts, ABC Dinamo, Klim Type Foundry, Velvetyne. Look for something that fits the brand as a physical object — a museum exhibit caption, a hand-painted shop sign, a 1970s mainframe terminal manual, a fabric label on the inside of a coat, a children's book printed on cheap newsprint. Reject the first thing that "looks designy" — that's the trained reflex too. Keep looking.

Step 4. Cross-check the result. The right font for an "elegant" brief is NOT necessarily a serif. The right font for a "technical" brief is NOT necessarily a sans-serif. The right font for a "warm" brief is NOT Fraunces. If your final pick lines up with your reflex pattern, go back to Step 3.

DO NOT use overused fonts like Inter, Roboto, Arial, Open Sans, or system defaults — but also do not simply switch to your second-favorite. Every font in the reflex_fonts_to_reject list above is banned. Look further. DO NOT use monospace typography as lazy shorthand for "technical/developer" vibes. DO NOT put large icons with rounded corners above every heading. They rarely add value and make sites look templated. DO NOT use only one font family for the entire page. Pair a distinctive display font with a refined body font. DO NOT use a flat type hierarchy where sizes are too close together. Aim for at least a 1.25 ratio between steps. DO NOT set long body passages in uppercase. Reserve all-caps for short labels and headings.

→ See anti-patterns reference § Typography for additional anti-patterns.

Color & Theme

→ Consult color reference for the deeper material on contrast, accessibility, and palette construction.

Commit to a cohesive palette. Dominant colors with sharp accents outperform timid, evenly-distributed palettes.

• Use OKLCH, not HSL. OKLCH is perceptually uniform: equal steps in lightness look equal, which HSL does not deliver. As you move toward white or black, REDUCE chroma — high chroma at extreme lightness looks garish. A light blue at 85% lightness wants ~0.08 chroma, not the 0.15 of your base color.
• Tint your neutrals toward your brand hue. Even a chroma of 0.005-0.01 is perceptible and creates subconscious cohesion between brand color and UI surfaces. The hue you tint toward should come from THIS brand, not from a "warm = friendly" or "cool = tech" formula. Pick the brand's actual hue first, then tint everything toward it.
• The 60-30-10 rule is about visual weight, not pixel count. 60% neutral / surface, 30% secondary text and borders, 10% accent. Accents work BECAUSE they're rare. Overuse kills their power.

• A perp DEX consumed during fast trading sessions → dark
• A hospital portal consumed by anxious patients on phones late at night → light
• A children's reading app → light
• A vintage motorcycle forum where users sit in their garage at 9pm → dark
• An observability dashboard for SREs in a dark office → dark
• A wedding planning checklist for couples on a Sunday morning → light
• A music player app for headphone listening at night → dark
• A food magazine homepage browsed during a coffee break → light

Do not default everything to light "to play it safe." Do not default everything to dark "to look cool." Both defaults are the lazy reflex. The correct theme is the one the actual user wants in their actual context.

DO NOT use gray text on colored backgrounds; it looks washed out. Use a shade of the background color instead. DO NOT use pure black (#000) or pure white (#fff). Always tint; pure black/white never appears in nature. DO NOT use the AI color palette: cyan-on-dark, purple-to-blue gradients, neon accents on dark backgrounds. DO NOT use gradient text for impact — see absolute_bans section below for the strict definition. Solid colors only for text. DO NOT default to dark mode with glowing accents. It looks "cool" without requiring actual design decisions. DO NOT default to light mode "to be safe" either. The point is to choose, not to retreat to a safe option.

→ See anti-patterns reference § Color & Theme for additional anti-patterns.

Layout & Space

→ Consult spatial reference for the deeper material on grids, container queries, and optical adjustments.

Create visual rhythm through varied spacing, not the same padding everywhere. Embrace asymmetry and unexpected compositions. Break the grid intentionally for emphasis.

• Use a 4pt spacing scale with semantic token names (--space-sm, --space-md), not pixel-named (--spacing-8). Scale: 4, 8, 12, 16, 24, 32, 48, 64, 96. 8pt is too coarse — you'll often want 12px between two values.
• Use gap instead of margins for sibling spacing. It eliminates margin collapse and the cleanup hacks that come with it.
• Vary spacing for hierarchy. A heading with extra space above it reads as more important — make use of that. Don't apply the same padding everywhere.
• Self-adjusting grid pattern: grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)) is the breakpoint-free responsive grid for card-style content.
• Container queries are for components, viewport queries are for page layout. A card in a sidebar should adapt to the sidebar's width, not the viewport's.

DO NOT wrap everything in cards. Not everything needs a container. DO NOT nest cards inside cards. Visual noise; flatten the hierarchy. DO NOT use identical card grids (same-sized cards with icon + heading + text, repeated endlessly). DO NOT use the hero metric layout template (big number, small label, supporting stats, gradient accent). DO NOT center everything. Left-aligned text with asymmetric layouts feels more designed. DO NOT use the same spacing everywhere. Without rhythm, layouts feel monotonous. DO NOT let body text wrap beyond ~80 characters per line. Add a max-width like 65–75ch so the eye can track easily.

→ See anti-patterns reference § Layout & Space for additional anti-patterns.

Visual Details

BAN 1: Side-stripe borders on cards/list items/callouts/alerts

• PATTERN: border-left: or border-right: with width greater than 1px
• INCLUDES: hard-coded colors AND CSS variables
• FORBIDDEN: border-left: 3px solid red, border-left: 4px solid #ff0000, border-left: 4px solid var(--color-warning), border-left: 5px solid oklch(...), etc.
• WHY: this is the single most overused "design touch" in admin, dashboard, and medical UIs. It never looks intentional regardless of color, radius, opacity, or whether the variable name is "primary" or "warning" or "accent."
• REWRITE: use a different element structure entirely. Do not just swap to box-shadow inset. Reach for full borders, background tints, leading numbers/icons, or no visual indicator at all.

BAN 2: Gradient text

• PATTERN: background-clip: text (or -webkit-background-clip: text) combined with a gradient background
• FORBIDDEN: any combination that makes text fill come from a linear-gradient, radial-gradient, or conic-gradient
• WHY: gradient text is decorative rather than meaningful and is one of the top three AI design tells
• REWRITE: use a single solid color for text. If you want emphasis, use weight or size, not gradient fill.

DO: Use intentional, purposeful decorative elements that reinforce brand. DO NOT: Use border-left or border-right greater than 1px as a colored accent stripe on cards, list items, callouts, or alerts. See absolute_bans section above for the strict CSS pattern. DO NOT: Use glassmorphism everywhere (blur effects, glass cards, glow borders used decoratively rather than purposefully). DO NOT: Use sparklines as decoration. Tiny charts that look sophisticated but convey nothing meaningful. DO NOT: Use rounded rectangles with generic drop shadows. Safe, forgettable, could be any AI output. DO NOT: Use modals unless there's truly no better alternative. Modals are lazy.

→ See anti-patterns reference § Visual Details for additional anti-patterns.

Motion

→ Consult motion reference for timing, easing, and reduced motion.

Focus on high-impact moments: one well-orchestrated page load with staggered reveals creates more delight than scattered micro-interactions.

DO: Use motion to convey state changes: entrances, exits, feedback DO: Use exponential easing (ease-out-quart/quint/expo) for natural deceleration DO: For accordion/content-reveal height animations, use grid-template-rows transitions instead of animating height directly DON'T: Animate layout properties (width, height, padding, margin) as a default. Prefer transform and opacity, except for intentional layout-driven reveal patterns like grid-template-rows accordions DON'T: Use bounce or elastic easing. They feel dated and tacky; real objects decelerate smoothly

→ See anti-patterns reference § Motion for additional anti-patterns.

Interaction

→ Consult interaction reference for forms, focus, and loading patterns.

Make interactions feel fast. Use optimistic UI—update immediately, sync later.

DO: Use progressive disclosure. Start simple, reveal sophistication through interaction (basic options first, advanced behind expandable sections; hover states that reveal secondary actions) DO: Design empty states that teach the interface, not just say "nothing here" DO: Make every interactive surface feel intentional and responsive DON'T: Repeat the same information (redundant headers, intros that restate the heading) DON'T: Make every button primary. Use ghost buttons, text links, secondary styles; hierarchy matters

→ See anti-patterns reference § Interaction & Copy for additional anti-patterns.

Responsive

→ Consult responsive reference for mobile-first, fluid design, and container queries.

DO: Use container queries (@container) for component-level responsiveness DO: Adapt the interface for different contexts, not just shrink it DON'T: Hide critical functionality on mobile. Adapt the interface, don't amputate it

UX Writing

→ Consult ux-writing reference for labels, errors, and empty states.

DO: Make every word earn its place DON'T: Repeat information users can already see

The AI Slop Test

→ Consult anti-patterns reference for the full AI Slop Test and all DON'T guidelines.

Critical quality check: If you showed this interface to someone and said "AI made this," would they believe you immediately? If yes, that's the problem. A distinctive interface should make someone ask "how was this made?" not "which AI made this?"

Implementation Principles

Match implementation complexity to the aesthetic vision. Maximalist designs need elaborate code with extensive animations and effects. Minimalist or refined designs need restraint, precision, and careful attention to spacing, typography, and subtle details.

Interpret creatively and make unexpected choices that feel genuinely designed for the context. No design should be the same. Vary between light and dark themes, different fonts, different aesthetics. NEVER converge on common choices across generations.

Remember: Claude is capable of extraordinary creative work. Don't hold back—show what can truly be created when thinking outside the box and committing fully to a distinctive vision.