W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.

Simple.css is classless CSS template that allows you to create a good looking website very quickly.

Color hex is a easy to use tool to get the color codes information including color models (RGB,HSL,HSV and CMYK), css and html color codes.

The CSS layout cookbook aims to bring together recipes for common layout patterns, things you might need to implement in your own sites. In addition to providing code you can use as a starting point in your projects, these recipes highlight the different ways layout specifications can be used, and the choices you can make as a developer.

A game for learning CSS grid layout

W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.

For artists and designers, bring your designs to life with our collection of online color tools and color palette inspiration.

When we truly learn the secrets of the Flexbox layout mode, we can build absolutely incredible things. Fluid layouts that stretch and shrink without arbitrary breakpoints. In this action-packed interactive tutorial, we'll pop the hood on the Flexbox algorithm and learn how to do remarkable things with it. ✨

CSS Reference is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and animated examples.

A series examining modern CSS solutions to problems Stephanie Eckles (@5t3ph), a seasoned frontend developer, has been solving for 15+ years.

A game for learning CSS flexbox