Source Code

UI/UX Design

Name: ui-ux-design
Description: Modern UI/UX design principles, patterns, and best practices for web and mobile applications. Use when building user interfaces, designing layouts, choosing color palettes, implementing responsive design, ensuring accessibility (WCAG), or creating beautiful modern applications. Includes 2026 design trends, Tailwind CSS patterns, Shadcn/ui integration, micro-interactions, and mobile-first responsive design.

Core Design Principles

1. Mobile-First Always

Start with 320px width (smallest phone)
Breakpoints: 576px (phone), 768px (tablet), 992px (laptop), 1200px (desktop)
Single-column default, expand only when space allows

2. Visual Hierarchy

Guide user attention using:

Size: Larger = more important
Color: Bright/contrasting = attention
Whitespace: More space = emphasis
Proximity: Related items grouped together
Contrast: Dark on light or light on dark (4.5:1 minimum for text)

3. Whitespace is Your Weapon

Space elements in multiples of 8px (8, 16, 24, 32, 48, 64)
Breathing room between sections: 48-64px minimum
Padding inside cards: 24-32px

Quick Reference

Color System

Build a primary color scale (50-900):

Primary: Brand color (CTAs, links, active states)
Neutrals: Grays 50-900 (text, backgrounds, borders)
Semantic: Success (green), Error (red), Warning (yellow/orange)

Tools: Huevy.app, Coolors.co, Adobe Color

Typography Scale (8px baseline)

text-xs:   12px / 16px line-height
text-sm:   14px / 20px
text-base: 16px / 24px (body default)
text-lg:   18px / 28px
text-xl:   20px / 28px
text-2xl:  24px / 32px
text-3xl:  30px / 36px (section headers)
text-4xl:  36px / 40px
text-5xl:  48px / 1 (hero titles)

Font pairing: 2 fonts max (sans-serif for UI, optional serif for headings)

Layout Patterns

CSS Grid: 2D layouts (page structure)
Flexbox: 1D layouts (component internals)
Auto-fit grid: repeat(auto-fit, minmax(280px, 1fr)) (no media queries!)

Micro-Interactions

Hover: Scale 1.05x (buttons feel clickable)
Click: Scale 0.95x (tactile feedback)
Duration: 0.2-0.3s max (keep it subtle)
Animate only: transform and opacity (GPU accelerated)

Accessibility (WCAG 2.2)

Text contrast: 4.5:1 minimum (normal text), 3:1 (large text)
UI components: 3:1 contrast minimum
Keyboard navigation: Tab order logical, focus states visible (3:1 contrast)
ARIA labels: Always provide for buttons, images, interactive elements

Shadcn/ui + Tailwind Stack

Setup (Next.js)

npx create-next-app@latest project-name --typescript --tailwind --app
cd project-name
npx shadcn@latest init

Choose: Style (Default), Base color (Blue or custom), CSS variables (Yes)

Adding Components

npx shadcn@latest add button
npx shadcn@latest add card
npx shadcn@latest add dialog
npx shadcn@latest add calendar

Components appear in components/ui/ — you own the code, customize freely.

Tailwind Best Practices

Use design tokens (not arbitrary values): p-4 not p-[17px]
Responsive utilities: w-full md:w-1/2 lg:w-1/3
Dark mode: dark:bg-gray-900 dark:text-white

Pre-Build Checklist

Before writing code, confirm:

Color palette defined (primary + neutrals + semantic colors)
Typography scale chosen (6-8 sizes)
Component library picked (Shadcn + Tailwind)
Mobile breakpoints planned (576px, 768px, 992px)
Accessibility contrast ratios checked (4.5:1 text, 3:1 UI)
Micro-interaction list (hover, click, success states)
Grid layout sketched (mobile → desktop progression)

Inspiration Sources

Study these products:

Linear (linear.app) — Best keyboard-first UI, subtle animations
Stripe Dashboard — Clean data visualization, perfect spacing
Vercel — Minimalist, fast, modern gradients
Notion — Intuitive drag-and-drop, clear hierarchy

Tools:

Figma (mockups before coding)
WebAIM Contrast Checker (accessibility)
Coolors/Huevy (color palettes)

The 5 Laws of Beautiful UI

Contrast creates hierarchy (big vs small, dark vs light)
Whitespace creates calm (never fear empty space)
Consistency builds trust (same patterns repeated)
Feedback confirms action (animations, success messages)
Accessibility includes everyone (contrast, keyboard, screen readers)

Full Reference

For comprehensive deep-dives (component patterns, animation examples, responsive grid techniques), see UI_UX_MASTER_GUIDE.md in this skill directory.

Last Updated: 2026-02-05