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A comprehensive guide for creating animations that feel right, based on Emil Kowalski's "Animations on the Web" course.

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Fundamental design principles for writing maintainable, testable Python code. \n \n Covers five core patterns: KISS (Keep It Simple), Single Responsibility Principle, Separation of Concerns, Composition Over Inheritance, and the Rule of Three \n Includes practical code examples contrasting anti-patterns with recommended approaches for each principle \n Provides layered architecture guidance (API, Service, Repository layers) with dependency injection patterns for testability \n Emphasizes explici

React Native and Expo best practices for performant mobile apps across list rendering, animations, navigation, and native modules. \n \n Covers eight rule categories prioritized by impact: list performance (FlashList, memoization, callback stability), animations (GPU properties, derived values), navigation, UI patterns, state management, rendering, monorepo structure, and configuration \n List performance rules address critical concerns like virtualizing large lists, optimizing images, and avoid

Setup and usage of next-intl with prefix-based locale routing (e.g. /en/about, /ja/about). Use this skill in any Next.js App Router project.

Universal React UI framework for web and native with an optimizing compiler.

Implement purposeful, performant animations that enhance UX without overwhelming users. Focus on key moments: hero intros, hover feedback, content reveals, and navigation transitions.

Use this skill in two modes:

HTML-first slide deck creation with visual editing, validation, and export to PPTX or PDF. \n \n Plan decks with structured outlines before generating HTML slides; review visually in a browser editor before exporting \n Organize slides in dedicated workspace directories ( decks/<deck-name>/ ) with self-contained HTML files, one primary idea per slide \n Validate slide structure and convert approved decks to .pptx or .pdf using core commands: build-viewer , validate , convert , pdf \n Requir

Create zero-dependency, animation-rich HTML presentations with visual style discovery. \n \n Supports three workflows: building new decks from scratch, converting PowerPoint files to HTML, and enhancing existing presentations with improved layout and motion \n Enforces viewport-fit constraint: every slide must fit in one viewport with no internal scrolling, using clamp() for responsive scaling and Intersection Observer for reveal animations \n Defaults to visual exploration over abstract questio