The article discusses the use of the sibling-index() and sibling-count() functions in CSS to determine an element's position among its siblings and the total number of siblings. It also highlights how to create custom functions to simplify the code while utilizing these features. However, it notes that these functions currently have limited browser support, primarily in Chrome.

A collection of CSS custom functions is available that utilizes the native CSS @function rule, requiring no build step for integration. Currently supported in Chrome 141+, it includes around 43 functions for various tasks, including math, color manipulation, typography, and layout, making CSS more efficient and streamlined for developers.