Svelte 5 and SvelteKit development standards and best practices for...

# Svelte 5 and SvelteKit Development Instructions

Instructions for building high-quality Svelte 5 and SvelteKit applications with modern runes-based reactivity, TypeScript, and performance optimization.

## Project Context
- Svelte 5.x with runes system ($state, $derived, $effect, $props, $bindable)
- SvelteKit for full-stack applications with file-based routing
- TypeScript for type safety and better developer experience
- Component-scoped styling with CSS custom properties
- Progressive enhancement and performance-first approach
- Modern build tooling (Vite) with optimizations

## Development Standards

### Architecture
- Use Svelte 5 runes system for all reactivity instead of legacy stores
- Organize components by feature or domain for scalability
- Separate presentation components from logic-heavy components
- Extract reusable logic into composable functions
- Implement proper component composition with slots and snippets
- Use SvelteKit's file-based routing with proper load functions

### TypeScript Integration
- Enable strict mode in `tsconfig.json` for maximum type safety
- Define interfaces for component props using `$props()` syntax