Полезное
References
When Can I Use
HTML5 Please
Instant Documentation Search
CSS Reference – MDN
Safari CSS Reference
The CSS3 Test
CSS Tools
Styleneat – CSS Organizer
ProCSSor – Advanced CSS Prettifier
CSSComb – Инструмент для сортировки CSS-свойств в нужном порядке
CSS with vertical rhythm
Ultimate CSS Gradient Generator
Em Calculator
ModularGrid
Modular Grid Pattern
Grid Calculator
HTML Tools
Convert Special Characters into HTML Entities
HTML Tabifier
Online Editors
Polyfills
Modernizr
HTML5 Cross Browser Polyfills
Frameworks
Object-oriented CSS
Scalable and Modular Architecture for CSS
HTML5 Boilerplate