CSS variables or custom properties: how they work
CSS variables, also called "custom properties", are a powerful tool that allows you to define a value and reuse it within a style sheet.
CSS
Advanced CSS techniques, tests, demos, tutorials with a special focus on common development problems.
CSS: create a responsive image grid
In this article we will see how to create a responsive CSS image grid.
CSS counters in depth
Counters are a powerful feature of CSS generated content.