name	modern-ui-designer
description	Expert guidance for creating stunning, professional 2025 UI designs using Tailwind CSS and shadcn/ui. Ensures clean minimal aesthetics, 8px grid consistency, mobile-first responsive patterns, and WCAG accessibility compliance. Use when designing interfaces, reviewing UI, creating components, or when visual design needs modern professional standards.
license	MIT
metadata	[object Object]

Modern UI Designer - 2025 Standards

Overview

This skill provides comprehensive guidance for creating world-class UI designs that follow modern 2025 standards. It covers Tailwind CSS best practices, shadcn/ui component patterns, clean minimalist design principles, 8px grid spacing systems, mobile-first responsive design, and WCAG accessibility compliance.

Core Philosophy: Professional, minimal, accessible, and consistent.

Design Principles (2025)

1. Clean Minimalism

Core Rules:

Remove the unnecessary: Every element must have a clear purpose
Whitespace is powerful: Generous spacing improves readability and reduces cognitive load
Content-first: Design serves content, not the other way around
Visual hierarchy: Use size, color, and spacing to guide attention
Subtle over flashy: Professional designs use restraint

What to Avoid:

❌ Rainbow gradients or excessive colors
❌ Decorative elements without function
❌ Complex patterns or textures
❌ Overcrowded interfaces
❌ Inconsistent spacing

What to Embrace:

✅ Neutral color palette (grays + one accent color)
✅ Generous whitespace and breathing room
✅ Clean typography with clear hierarchy
✅ Subtle shadows and borders
✅ Consistent 8px grid system

2. Visual Hierarchy Best Practices

Size:

Use dramatic size differences for headings vs body text
Minimum 16px for body text (18px preferred for readability)
Heading scale: 48px → 32px → 24px → 20px → 18px → 16px
Use Tailwind's text-* utilities: text-6xl, text-4xl, text-2xl, text-xl, text-lg, text-base

Color:

Use color strategically to indicate importance
Primary actions: Accent color
Secondary actions: Neutral gray
Disabled states: Low contrast gray
Error states: Red (accessible contrast)
Success states: Green (accessible contrast)

Weight:

Headings: font-bold (700) or font-semibold (600)
Body: font-normal (400) or font-medium (500)
Captions: font-light (300) with careful use

Spacing:

Large spacing (32px+) separates major sections
Medium spacing (16-24px) groups related content
Small spacing (8px) for tightly related items
Internal ≤ External rule: Space inside elements should be less than space between them

8px Grid System

Core Concept

All spacing, sizing, and layout must use multiples of 8:

Base units: 8px, 16px, 24px, 32px, 40px, 48px, 56px, 64px, 72px, 80px
Half unit: 4px (only for icons, borders, or micro-adjustments)
Never use: 7px, 13px, 25px, or other non-conforming values

Why 8px?

Device compatibility: Most screen resolutions are divisible by 8
Scaling: Works perfectly across @1x, @2x, @3x displays
Visual consistency: Easy to eyeball and maintain rhythm
Developer-friendly: Reduces translation errors from design to code

Tailwind CSS Spacing Scale

Tailwind's spacing scale aligns perfectly with 8px grid:

0   →  0px
0.5 →  2px   (exception for borders)
1   →  4px   (half unit)
2   →  8px   (base)
3   →  12px  (1.5 units, use sparingly)
4   →  16px  (2 units)
5   →  20px  (2.5 units, use sparingly)
6   →  24px  (3 units)
8   →  32px  (4 units)
10  →  40px  (5 units)
12  →  48px  (6 units)
16  →  64px  (8 units)
20  →  80px  (10 units)
24  →  96px  (12 units)
32  →  128px (16 units)

Preferred values for spacing:

Padding: p-2, p-4, p-6, p-8, p-12, p-16
Margin: m-2, m-4, m-6, m-8, m-12, m-16
Gap: gap-2, gap-4, gap-6, gap-8

Spacing Hierarchy (Proximity Principle)

Tightly related (8px - 16px):

<div class="space-y-2">
  <h3 class="text-xl font-semibold">Heading</h3>
  <p class="text-gray-600">Subheading</p>
</div>

Related content (24px - 32px):

<div class="space-y-6">
  <section><!-- Content --></section>
  <section><!-- Content --></section>
</div>

Separate sections (48px - 64px):

<div class="space-y-12 md:space-y-16">
  <section><!-- Major section --></section>
  <section><!-- Major section --></section>
</div>

Component Sizing with 8px Grid

Buttons:

Small: h-8 (32px) with px-3 py-1.5
Medium: h-10 (40px) with px-4 py-2
Large: h-12 (48px) with px-6 py-3
Extra Large: h-14 (56px) with px-8 py-4

Input Fields:

Height: h-10 (40px) or h-12 (48px)
Padding: px-3 py-2 or px-4 py-3

Cards:

Padding: p-4, p-6, or p-8 depending on content
Border radius: rounded-md (6px), rounded-lg (8px), rounded-xl (12px)

Color System (Neutral + Accent)

The Neutral Palette Approach

Base Strategy: Gray scale + ONE accent color

Gray Scale (Tailwind):

slate-50   → Backgrounds
slate-100  → Subtle backgrounds
slate-200  → Borders, dividers
slate-300  → Disabled text
slate-400  → Placeholder text
slate-500  → Secondary text
slate-600  → Body text
slate-700  → Headings
slate-800  → Emphasis
slate-900  → Maximum contrast

Accent Color Selection:

Choose ONE primary brand color
Use for: Primary buttons, links, active states, highlights
Shades needed: 50, 100, 200, 300, 400, 500, 600, 700, 800, 900
Example: blue-600 for primary, blue-700 for hover

Semantic Colors (Minimal Use)

<!-- Success -->
<div class="bg-green-50 text-green-700 border border-green-200">

<!-- Warning -->
<div class="bg-yellow-50 text-yellow-800 border border-yellow-200">

<!-- Error -->
<div class="bg-red-50 text-red-700 border border-red-200">

<!-- Info -->
<div class="bg-blue-50 text-blue-700 border border-blue-200">

Dark Mode Support

<!-- Neutral backgrounds -->
<div class="bg-white dark:bg-slate-900 text-slate-900 dark:text-slate-50">

<!-- Borders -->
<div class="border border-slate-200 dark:border-slate-800">

<!-- Subtle backgrounds -->
<div class="bg-slate-50 dark:bg-slate-800">

<!-- Primary accent -->
<button class="bg-blue-600 hover:bg-blue-700 dark:bg-blue-500 dark:hover:bg-blue-600">

Color Contrast Rules (WCAG)

Text Contrast Ratios:

Normal text (< 24px): Minimum 4.5:1
Large text (≥ 24px): Minimum 3:1
UI components & graphics: Minimum 3:1

Safe Combinations:

✅ slate-900 on white → 18.9:1
✅ slate-700 on white → 8.6:1
✅ slate-600 on white → 6.2:1
✅ blue-600 on white → 5.4:1
❌ slate-400 on white → 2.9:1 (fails)
❌ slate-300 on white → 1.7:1 (fails)

Tailwind CSS Best Practices (2025)

1. Utility-First Approach

DO:

<!-- ✅ Compose utilities directly -->
<button class="px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 
               focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2
               transition-colors duration-200">
  Click me
</button>

DON'T:

/* ❌ Avoid custom CSS unless absolutely necessary */
.custom-button {
  padding: 0.5rem 1rem;
  background: #3b82f6;
  /* ... */
}

2. Component Extraction with @apply (Sparingly)

Use @apply ONLY for:

Components used 10+ times
Third-party library overrides
Print stylesheets

/* ✅ Good use of @apply */
@layer components {
  .btn-primary {
    @apply px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 
           focus:outline-none focus:ring-2 focus:ring-blue-500;
  }
}

3. Responsive Design (Mobile-First)

Breakpoints:

sm:  640px  → Small tablets
md:  768px  → Tablets
lg:  1024px → Desktop
xl:  1280px → Large desktop
2xl: 1536px → Extra large

Pattern:

<!-- Mobile first, then scale up -->
<div class="p-4 md:p-6 lg:p-8">
  <h1 class="text-2xl md:text-3xl lg:text-4xl">
    Responsive Heading
  </h1>
</div>

<!-- Grid responsive -->
<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4 md:gap-6">
  <!-- Items -->
</div>

4. State Variants

Hover, Focus, Active:

<button class="bg-blue-600 hover:bg-blue-700 active:bg-blue-800
               focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2
               disabled:opacity-50 disabled:cursor-not-allowed">

Dark Mode:

<div class="bg-white dark:bg-slate-900 
            text-slate-900 dark:text-slate-50
            border border-slate-200 dark:border-slate-800">

5. Class Organization (Consistent Order)

Standard order:

Layout (display, position, overflow)
Sizing (width, height)
Spacing (margin, padding)
Typography (font, text)
Visual (background, border)
Effects (shadow, opacity)
Transitions
Variants (hover, focus, dark)

<!-- ✅ Organized -->
<div class="
  flex items-center justify-between
  w-full max-w-screen-lg
  px-4 py-3 my-2
  text-lg font-medium text-gray-800
  bg-white rounded shadow
  hover:shadow-md
  transition-shadow
">

6. JIT Mode & Purging

Always enable JIT (Just-In-Time mode):

// tailwind.config.js
module.exports = {
  content: [
    './src/**/*.{html,js,jsx,ts,tsx}',
    './components/**/*.{html,js,jsx,ts,tsx}',
  ],
  // ... rest of config
}

Benefits:

Smaller CSS bundle
Arbitrary values: w-[373px]
All variants available
Faster build times

shadcn/ui Component Patterns

Architecture Understanding

shadcn/ui = Radix UI + Tailwind CSS + CVA:

Radix UI: Unstyled, accessible primitives
Tailwind CSS: Utility-first styling
CVA (Class Variance Authority): Variant management

Core Pattern: Copy, Own, Customize

NOT a package: You copy component source into your project

Full ownership of code
No breaking updates
Complete customization
Type-safe variants

Component Anatomy Example

// Button.tsx
import { cva, type VariantProps } from "class-variance-authority"
import { cn } from "@/lib/utils"

const buttonVariants = cva(
  // Base styles (always applied)
  "inline-flex items-center justify-center rounded-lg font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50",
  {
    variants: {
      variant: {
        default: "bg-slate-900 text-slate-50 hover:bg-slate-800",
        outline: "border border-slate-200 bg-transparent hover:bg-slate-100",
        ghost: "hover:bg-slate-100",
      },
      size: {
        sm: "h-8 px-3 text-sm",
        md: "h-10 px-4",
        lg: "h-12 px-6 text-lg",
      },
    },
    defaultVariants: {
      variant: "default",
      size: "md",
    },
  }
)

interface ButtonProps
  extends React.ButtonHTMLAttributes<HTMLButtonElement>,
    VariantProps<typeof buttonVariants> {}

export const Button = ({ className, variant, size, ...props }: ButtonProps) => {
  return (
    <button
      className={cn(buttonVariants({ variant, size }), className)}
      {...props}
    />
  )
}

Best Practices for shadcn/ui

1. Use cn() utility for class merging:

import { cn } from "@/lib/utils"

// Allows className override
<Button className={cn("custom-class", conditionalClass && "other-class")} />

2. Design System Integration:

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        border: "hsl(var(--border))",
        input: "hsl(var(--input))",
        ring: "hsl(var(--ring))",
        background: "hsl(var(--background))",
        foreground: "hsl(var(--foreground))",
        primary: {
          DEFAULT: "hsl(var(--primary))",
          foreground: "hsl(var(--primary-foreground))",
        },
        // ... more design tokens
      },
    },
  },
}

3. CSS Variables for Theming:

:root {
  --background: 0 0% 100%;
  --foreground: 222.2 84% 4.9%;
  --primary: 221.2 83.2% 53.3%;
  --primary-foreground: 210 40% 98%;
  --border: 214.3 31.8% 91.4%;
  --radius: 0.5rem;
}

.dark {
  --background: 222.2 84% 4.9%;
  --foreground: 210 40% 98%;
  --primary: 217.2 91.2% 59.8%;
  --primary-foreground: 222.2 47.4% 11.2%;
  --border: 217.2 32.6% 17.5%;
}

Common Patterns

Form Field with Label:

<div className="space-y-2">
  <Label htmlFor="email">Email</Label>
  <Input
    id="email"
    type="email"
    placeholder="you@example.com"
    className="w-full"
  />
  <p className="text-sm text-slate-500">
    We'll never share your email.
  </p>
</div>

Card Layout:

<Card>
  <CardHeader>
    <CardTitle>Card Title</CardTitle>
    <CardDescription>Card description goes here</CardDescription>
  </CardHeader>
  <CardContent>
    <!-- Main content -->
  </CardContent>
  <CardFooter>
    <!-- Actions -->
  </CardFooter>
</Card>

Dialog Pattern:

<Dialog>
  <DialogTrigger asChild>
    <Button variant="outline">Open Dialog</Button>
  </DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>Dialog Title</DialogTitle>
      <DialogDescription>
        Dialog description text
      </DialogDescription>
    </DialogHeader>
    <!-- Dialog content -->
    <DialogFooter>
      <Button variant="outline">Cancel</Button>
      <Button>Confirm</Button>
    </DialogFooter>
  </DialogContent>
</Dialog>

Accessibility (WCAG 2.2 Compliance)

The Four Principles (POUR)

1. Perceivable:

Text alternatives for images
Captions for videos
Adaptable content structure
Sufficient color contrast

2. Operable:

Keyboard accessible
No keyboard traps
Sufficient time to interact
No seizure-inducing content

3. Understandable:

Readable text
Predictable behavior
Input assistance and error prevention

4. Robust:

Compatible with assistive technologies
Valid HTML
Proper ARIA attributes

Critical Requirements

Keyboard Navigation:

<!-- ✅ Proper focus management -->
<button
  class="focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2"
>
  Accessible Button
</button>

<!-- ✅ Skip links -->
<a href="#main-content" class="sr-only focus:not-sr-only focus:absolute focus:top-0 focus:left-0">
  Skip to main content
</a>

Focus Indicators (WCAG 2.2):

Must be visible
Minimum 2px thickness
Contrast ratio of 3:1 against background
Use focus:ring-2 and focus:ring-offset-2

Touch Targets:

Minimum 44x44px (WCAG 2.1)
Minimum 24x24px spacing (WCAG 2.2)
Use min-h-[44px] min-w-[44px] for interactive elements

Color Contrast:

<!-- ✅ Good contrast -->
<p class="text-slate-700">Body text</p> <!-- 8.6:1 -->
<button class="bg-blue-600 text-white">Action</button> <!-- 5.4:1 -->

<!-- ❌ Poor contrast -->
<p class="text-slate-400">Fails WCAG</p> <!-- 2.9:1 -->

Semantic HTML:

<!-- ✅ Use proper semantic elements -->
<header>
  <nav aria-label="Main navigation">
    <ul>
      <li><a href="/">Home</a></li>
    </ul>
  </nav>
</header>

<main>
  <article>
    <h1>Page Title</h1>
    <section>
      <h2>Section Heading</h2>
      <!-- Content -->
    </section>
  </article>
</main>

<footer>
  <!-- Footer content -->
</footer>

ARIA Labels:

<!-- Icon-only buttons -->
<button aria-label="Close dialog" class="...">
  <XIcon className="h-4 w-4" aria-hidden="true" />
</button>

<!-- Form labels -->
<label for="search" class="sr-only">Search</label>
<input id="search" type="search" />

<!-- Live regions -->
<div role="status" aria-live="polite" aria-atomic="true">
  Loading...
</div>

Form Accessibility:

<form>
  <div>
    <label for="email" class="block text-sm font-medium mb-2">
      Email
      <span class="text-red-600" aria-label="required">*</span>
    </label>
    <input
      id="email"
      type="email"
      required
      aria-required="true"
      aria-describedby="email-error"
      aria-invalid={hasError ? "true" : "false"}
      class="w-full"
    />
    {hasError && (
      <p id="email-error" class="text-sm text-red-600 mt-1" role="alert">
        Please enter a valid email address
      </p>
    )}
  </div>
</form>

Mobile-First Responsive Design

Strategy

Start with mobile (320px - 640px):

Design for smallest screen first
Optimize for touch interactions
Prioritize content hierarchy
Progressive enhancement for larger screens

Responsive Patterns

Container Width:

<!-- Responsive container -->
<div class="container mx-auto px-4 md:px-6 lg:px-8 max-w-7xl">
  <!-- Content -->
</div>

Typography Scale:

<!-- Responsive text -->
<h1 class="text-3xl md:text-4xl lg:text-5xl font-bold">
  Responsive Heading
</h1>

<p class="text-base md:text-lg leading-relaxed">
  Body text with responsive sizing
</p>

Grid Layouts:

<!-- Responsive grid -->
<div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-4 lg:gap-6">
  <div><!-- Card --></div>
  <div><!-- Card --></div>
  <div><!-- Card --></div>
</div>

Flexbox Responsive:

<!-- Stack on mobile, row on desktop -->
<div class="flex flex-col md:flex-row gap-4 md:gap-6">
  <div class="flex-1"><!-- Content --></div>
  <div class="flex-1"><!-- Content --></div>
</div>

Visibility Control:

<!-- Hide on mobile, show on desktop -->
<div class="hidden md:block">
  Desktop only content
</div>

<!-- Show on mobile, hide on desktop -->
<div class="block md:hidden">
  Mobile only content
</div>

Navigation Pattern:

<!-- Mobile: Hamburger menu -->
<!-- Desktop: Horizontal nav -->
<nav>
  <!-- Mobile menu button -->
  <button class="md:hidden">
    <MenuIcon />
  </button>
  
  <!-- Desktop nav -->
  <ul class="hidden md:flex md:space-x-4">
    <li><a href="/">Home</a></li>
    <li><a href="/about">About</a></li>
  </ul>
</nav>

Typography System

Font Selection

Modern Professional Fonts:

Sans-serif: Inter, SF Pro, -apple-system, system-ui
Monospace: JetBrains Mono, Fira Code, SF Mono

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      fontFamily: {
        sans: ['Inter', 'system-ui', 'sans-serif'],
        mono: ['JetBrains Mono', 'monospace'],
      },
    },
  },
}

Type Scale (8px-based)

text-xs   → 12px (line-height: 16px)
text-sm   → 14px (line-height: 20px)
text-base → 16px (line-height: 24px) ← Body text default
text-lg   → 18px (line-height: 28px)
text-xl   → 20px (line-height: 28px)
text-2xl  → 24px (line-height: 32px)
text-3xl  → 30px (line-height: 36px)
text-4xl  → 36px (line-height: 40px)
text-5xl  → 48px (line-height: 48px)
text-6xl  → 60px (line-height: 60px)

Line Heights

Always use 8px-aligned line heights:

<!-- Body text -->
<p class="text-base leading-6"> <!-- 16px text, 24px line-height -->

<!-- Headings -->
<h2 class="text-3xl leading-9"> <!-- 30px text, 36px line-height -->

Text Hierarchy Example

<article class="space-y-6">
  <!-- Main heading -->
  <h1 class="text-4xl md:text-5xl font-bold text-slate-900 leading-tight">
    Article Title
  </h1>
  
  <!-- Subtitle -->
  <p class="text-xl text-slate-600 leading-relaxed">
    Engaging subtitle or description
  </p>
  
  <!-- Meta information -->
  <div class="flex items-center gap-4 text-sm text-slate-500">
    <span>By Author Name</span>
    <span>•</span>
    <time datetime="2025-01-15">Jan 15, 2025</time>
  </div>
  
  <!-- Body content -->
  <div class="prose prose-slate max-w-none">
    <p class="text-base leading-relaxed text-slate-700">
      Body paragraph with comfortable reading size and spacing...
    </p>
  </div>
</article>

Shadows & Elevation

Shadow System (Subtle Professional)

<!-- Subtle card elevation -->
<div class="shadow-sm"> <!-- Very subtle -->
<div class="shadow">    <!-- Default card -->
<div class="shadow-md"> <!-- Slightly raised -->
<div class="shadow-lg"> <!-- Pronounced elevation -->
<div class="shadow-xl"> <!-- Modal/dialog -->

<!-- Custom shadows (use sparingly) -->
<div class="shadow-[0_2px_8px_rgba(0,0,0,0.08)]">

Modern Pattern: Combine shadow with border

<div class="border border-slate-200 shadow-sm rounded-lg">
  <!-- More refined than shadow alone -->
</div>

Elevation States

<!-- Card hover effect -->
<div class="border border-slate-200 shadow-sm hover:shadow-md 
            transition-shadow duration-200 rounded-lg">
  Hover me
</div>

Border Radius Guidelines

Consistent Rounding

rounded-none → 0px
rounded-sm   → 2px   (subtle, modern)
rounded      → 4px   (default)
rounded-md   → 6px   (cards)
rounded-lg   → 8px   (buttons, inputs) ← Preferred
rounded-xl   → 12px  (large cards)
rounded-2xl  → 16px  (hero sections)
rounded-full → 9999px (circles, pills)

2025 Trend: Larger, softer corners (8px - 12px)

<!-- Modern button -->
<button class="px-4 py-2 bg-blue-600 text-white rounded-lg">

<!-- Card -->
<div class="border border-slate-200 rounded-xl p-6">

<!-- Avatar -->
<img class="h-10 w-10 rounded-full" />

Component Design Examples

Modern Button

<!-- Primary -->
<button class="
  inline-flex items-center justify-center
  h-10 px-4
  text-base font-medium
  bg-blue-600 text-white
  rounded-lg
  hover:bg-blue-700
  focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2
  active:bg-blue-800
  disabled:opacity-50 disabled:cursor-not-allowed
  transition-colors duration-200
">
  Primary Action
</button>

<!-- Secondary -->
<button class="
  inline-flex items-center justify-center
  h-10 px-4
  text-base font-medium
  border border-slate-300 bg-white text-slate-700
  rounded-lg
  hover:bg-slate-50
  focus:outline-none focus:ring-2 focus:ring-slate-500 focus:ring-offset-2
  disabled:opacity-50 disabled:cursor-not-allowed
  transition-colors duration-200
">
  Secondary Action
</button>

<!-- Ghost -->
<button class="
  inline-flex items-center justify-center
  h-10 px-4
  text-base font-medium text-slate-700
  rounded-lg
  hover:bg-slate-100
  focus:outline-none focus:ring-2 focus:ring-slate-500 focus:ring-offset-2
  transition-colors duration-200
">
  Ghost Button
</button>

Modern Input Field

<div class="space-y-2">
  <label 
    for="email" 
    class="block text-sm font-medium text-slate-700"
  >
    Email address
  </label>
  <input
    id="email"
    type="email"
    placeholder="you@example.com"
    class="
      w-full h-10 px-3
      text-base text-slate-900 placeholder:text-slate-400
      bg-white
      border border-slate-300 rounded-lg
      focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent
      disabled:bg-slate-50 disabled:text-slate-500 disabled:cursor-not-allowed
      transition-colors duration-200
    "
  />
  <p class="text-sm text-slate-500">
    We'll never share your email with anyone else.
  </p>
</div>

Modern Card

<div class="
  bg-white
  border border-slate-200
  rounded-xl
  shadow-sm hover:shadow-md
  transition-shadow duration-200
  overflow-hidden
">
  <!-- Card header with image -->
  <div class="aspect-video bg-slate-100">
    <img 
      src="..." 
      alt="..."
      class="w-full h-full object-cover"
    />
  </div>
  
  <!-- Card content -->
  <div class="p-6 space-y-4">
    <!-- Heading -->
    <h3 class="text-xl font-semibold text-slate-900">
      Card Title
    </h3>
    
    <!-- Description -->
    <p class="text-base text-slate-600 leading-relaxed">
      Card description goes here with comfortable reading spacing.
    </p>
    
    <!-- Actions -->
    <div class="flex items-center gap-3">
      <button class="...">Primary</button>
      <button class="...">Secondary</button>
    </div>
  </div>
</div>

Modern Navigation

<header class="sticky top-0 z-50 bg-white border-b border-slate-200">
  <nav class="container mx-auto px-4 md:px-6">
    <div class="flex items-center justify-between h-16">
      <!-- Logo -->
      <a href="/" class="flex items-center gap-2">
        <img src="logo.svg" alt="Logo" class="h-8 w-8" />
        <span class="text-xl font-bold text-slate-900">Brand</span>
      </a>
      
      <!-- Desktop navigation -->
      <ul class="hidden md:flex items-center gap-8">
        <li>
          <a href="/" class="text-sm font-medium text-slate-700 hover:text-slate-900">
            Home
          </a>
        </li>
        <li>
          <a href="/about" class="text-sm font-medium text-slate-700 hover:text-slate-900">
            About
          </a>
        </li>
        <li>
          <a href="/contact" class="text-sm font-medium text-slate-700 hover:text-slate-900">
            Contact
          </a>
        </li>
      </ul>
      
      <!-- CTA -->
      <button class="hidden md:inline-flex ...">
        Get Started
      </button>
      
      <!-- Mobile menu button -->
      <button class="md:hidden" aria-label="Open menu">
        <MenuIcon class="h-6 w-6" />
      </button>
    </div>
  </nav>
</header>

Anti-Patterns to Avoid

❌ DON'T DO THESE

1. Inconsistent Spacing:

<!-- ❌ Bad: Random spacing values -->
<div class="mt-3 mb-5 px-7">

<!-- ✅ Good: 8px grid aligned -->
<div class="my-4 px-6">

2. Poor Color Contrast:

<!-- ❌ Bad: Fails WCAG -->
<p class="text-slate-400">Important text</p>

<!-- ✅ Good: Passes WCAG -->
<p class="text-slate-700">Important text</p>

3. Missing Focus Styles:

<!-- ❌ Bad: No focus indicator -->
<button class="outline-none">

<!-- ✅ Good: Clear focus ring -->
<button class="focus:outline-none focus:ring-2 focus:ring-blue-500">

4. Non-Semantic HTML:

<!-- ❌ Bad: Divs for everything -->
<div onClick="navigate()">Home</div>

<!-- ✅ Good: Semantic elements -->
<a href="/home">Home</a>

5. Tiny Touch Targets:

<!-- ❌ Bad: Too small for touch -->
<button class="p-1">×</button>

<!-- ✅ Good: Minimum 44x44px -->
<button class="p-3 min-h-[44px] min-w-[44px]">×</button>

6. Over-Styled Designs:

<!-- ❌ Bad: Rainbow chaos -->
<div class="bg-gradient-to-r from-purple-500 via-pink-500 to-red-500 
            shadow-2xl border-4 border-yellow-400 rounded-3xl">

<!-- ✅ Good: Minimal & professional -->
<div class="bg-white border border-slate-200 rounded-lg shadow-sm">

7. Fixed Pixel Widths:

<!-- ❌ Bad: Breaks on small screens -->
<div class="w-[800px]">

<!-- ✅ Good: Responsive -->
<div class="w-full max-w-3xl">

Quick Review Checklist

Design Review (Before Development)

Visual Design:

Uses neutral color palette (grays + 1 accent)
Follows 8px grid for all spacing and sizing
Maintains consistent border radius (8px - 12px)
Uses subtle shadows (not heavy drop shadows)
Typography hierarchy is clear
Whitespace is generous and purposeful

Responsiveness:

Mobile-first design approach
Touch targets are minimum 44x44px
Text is readable without zooming
Content reflows properly at all breakpoints
Navigation works on mobile

Accessibility:

Color contrast meets WCAG 2.2 (4.5:1 minimum)
Focus indicators are visible (2px ring)
Semantic HTML used correctly
ARIA labels on icon-only buttons
Form labels are properly associated

Components:

Buttons have hover, focus, and active states
Form inputs have validation states
Loading states are designed
Error states are clear and helpful
Empty states are friendly

Development Review (After Implementation)

Technical:

Tailwind classes follow consistent order
JIT mode enabled and purging configured
No custom CSS unless absolutely necessary
Dark mode support implemented
Performance optimized (lazy loading, etc.)

Accessibility Testing:

Keyboard navigation works completely
Screen reader tested (NVDA/VoiceOver)
Color contrast verified with tool
Forms are fully accessible
ARIA attributes used correctly

Responsive Testing:

Tested on mobile (375px, 414px)
Tested on tablet (768px, 1024px)
Tested on desktop (1280px, 1920px)
Touch interactions work properly
No horizontal scroll at any size

Advanced Techniques

1. Tailwind CSS Variables for Theming

@layer base {
  :root {
    /* Spacing */
    --spacing-xs: 0.5rem;  /* 8px */
    --spacing-sm: 1rem;    /* 16px */
    --spacing-md: 1.5rem;  /* 24px */
    --spacing-lg: 2rem;    /* 32px */
    
    /* Colors */
    --color-primary: 220 90% 56%;
    --color-primary-hover: 220 90% 48%;
    
    /* Border radius */
    --radius-sm: 0.5rem;  /* 8px */
    --radius-md: 0.75rem; /* 12px */
    --radius-lg: 1rem;    /* 16px */
  }
}

2. Custom Utility Classes

@layer utilities {
  /* Text balance for headings */
  .text-balance {
    text-wrap: balance;
  }
  
  /* Smooth scroll */
  .scroll-smooth {
    scroll-behavior: smooth;
  }
  
  /* Focus visible only */
  .focus-visible-ring {
    @apply focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-500;
  }
}

3. Component Composition Pattern

// Compose smaller components into larger ones
<Card>
  <CardHeader>
    <div className="flex items-center justify-between">
      <div className="space-y-1">
        <CardTitle>Dashboard</CardTitle>
        <CardDescription>Welcome back</CardDescription>
      </div>
      <Button variant="outline" size="sm">
        <SettingsIcon className="h-4 w-4" />
      </Button>
    </div>
  </CardHeader>
  <CardContent>
    <Tabs defaultValue="overview">
      <TabsList>
        <TabsTrigger value="overview">Overview</TabsTrigger>
        <TabsTrigger value="analytics">Analytics</TabsTrigger>
      </TabsList>
      <TabsContent value="overview" className="space-y-4">
        {/* Content */}
      </TabsContent>
    </Tabs>
  </CardContent>
</Card>

Resources & Tools

Design Tools

Figma: Primary design tool
Tailwind CSS IntelliSense: VS Code extension
Headless UI: Unstyled accessible components
Radix UI: Primitive components for shadcn/ui

Accessibility Testing

WAVE: Browser extension for accessibility testing
axe DevTools: Automated accessibility testing
Contrast Checker: Verify WCAG color contrast
NVDA/VoiceOver: Screen reader testing

Color Tools

Coolors: Color palette generator
Tailwind Shades: Generate Tailwind color scales
Contrast Ratio: WebAIM contrast checker

Typography

Typescale: Generate type scales
Modular Scale: Calculate harmonious sizes
Google Fonts: Free web fonts

Learning Resources

Tailwind CSS Documentation: Official docs
shadcn/ui Documentation: Component library docs
WCAG Guidelines: W3C accessibility standards
Refactoring UI: Design tips by Tailwind creators

Summary

Modern UI Design in 2025 means:

Clean Minimalism: Remove the unnecessary, embrace whitespace
8px Grid System: Consistent, scalable spacing and sizing
Neutral + Accent: Grays with one primary color
Tailwind CSS: Utility-first, JIT-enabled, responsive
shadcn/ui: Copy-and-own accessible components
WCAG 2.2: Full keyboard support and color contrast
Mobile-First: Design small screens first, scale up
Professional Polish: Subtle shadows, soft corners, smooth transitions

Remember: The goal is not to impress with flashy design, but to create interfaces that are beautiful, functional, accessible, and a pleasure to use.

When to Use This Skill

Activate this skill when:

Designing new UI components or pages
Reviewing existing designs for modern standards
Creating design systems or component libraries
Implementing Tailwind CSS or shadcn/ui
Ensuring accessibility compliance
Optimizing responsive layouts
Troubleshooting visual design issues
Teaching or documenting UI best practices

Output Format: Always provide code examples, explain design decisions, and reference specific Tailwind utilities or shadcn/ui components when applicable.

Install Skill

SKILL.md