- How to write truly terrible CSS - Freecodecamp
- CSS Naming Conventions - Freecodecamp
- A Primer to Well-Structured CSS
- PWA Builder - Create PWAs, publish it to app stores, etc… Site performance
- Webhint - Website analyzer from Microsoft and Open JS foundation.
- Google Pagespeed Insights - Analyze website performance
- web.dev - Measure - Similar to Pagespeed insights
- GTmetrix Validators
- W3C | HTML Validator
- W3C | CSS Validator
- W3C | Atom/RSS Feed Validator
- Can I Use - Browser support for modern web technologies
- Bootstrap - Responsive CSS framework.
- MaterializeCSS - A responsive framework based on Material Design.
- Ant Design - Design system for enterprise applications.
- UI kit - Lightweight and modular frontend framework
- Spectre - A Lightweight, Responsive and Modern CSS Framework
- Tailwind - A utility-first CSS framework for rapidly building custom designs.