W3C - CSS. What is CSS?
Cascading Style Sheets (CSS) is a simple mechanism for adding style (e.g., fonts, colors, spacing) to Web documents. These pages contain information on how to learn and use CSS and on available software. w3schools - CSS Reference. Responsive Web Design. This infographic is the first place to check when you need well researched information on responsive web design.
With basic glossary, 15 blog articles, 5 quotes, 11 free PDF books, Google recommendations, as well as 65 tutorials, 20 plugins, 19 tools, and ready-made responsive website templates, this page is meant to classify a whopping amount of RWD content and give you exhaustive answers & tips to help improve your website designs. Use this, it will make you a better responsive web designer.