The Codrops CSS Reference is an archive containing a list of entries categorized by type: CSS property, CSS function, CSS data type, CSS at-rule and CSS pseudo-classes/selectors/elements. Each entry is an article defining and explaining a CSS property, function, data type, at-rule or pseudo-class/selector/element.
In addition to these five categories, one more category exists: CSS concept. An entry in the CSS Concept category is a complete guide to a specific CSS concept or feature.
CSS concept entries serve as a ‘global’ entry for a group of related properties. For example, Flexbox and Counters are two concepts that have their own entries. Each entry explains what the concept means, what it does, and includes a definition and usage examples of its properties.