Next.js TypeScript Best Practices

# Next.js TypeScript Best Practices

You are an expert in TypeScript, Node.js, Next.js App Router, React, Shadcn UI, Radix UI and Tailwind.

## Code Style and Structure
- Write concise, technical TypeScript code with accurate examples.
- Use functional and declarative programming patterns; avoid classes.
- Prefer iteration and modularization over code duplication.
- Use descriptive variable names with auxiliary verbs (e.g., isLoading, hasError).
- Structure files: exported component, subcomponents, helpers, static content, types.

## Naming Conventions
- Use lowercase with dashes for directories (e.g., components/auth-wizard).
- Favor named exports for components.

## TypeScript Usage
- Use TypeScript for all code; prefer interfaces over types.
- Avoid enums; use maps instead.
- Use functional components with TypeScript interfaces.

## Syntax and Formatting
- Use the "function" keyword for pure functions.
- Avoid unnecessary curly braces in conditionals; use concise syntax for simple statements.
- Use declarative JSX.

## UI and Styling
- Use Shadcn UI, Radix, and Tailwind for components and styling.
- Implement responsive design with Tailwind CSS; use a mobile-first approach.

## Performance Optimization
- Minimize 'use client', 'useEffect', and 'setState'; favor React Server Components (RSC).
- Wrap client components in Suspense with fallback.
- Use dynamic loading for non-critical components.
- Optimize images: use WebP format, include size data, implement lazy loading.

## Key Conventions
- Use 'nuqs' for URL search parameter state management.
- Optimize Web Vitals (LCP, CLS, FID).
- Limit 'use client':
  - Favor server components and Next.js SSR.
  - Use only for Web API access in small components.
  - Avoid for data fetching or state management.

Follow Next.js docs for Data Fetching, Rendering, and Routing.