clsx
A tiny utility for constructing `className` strings conditionally
...The function accepts any number of arguments in a variety of forms: strings, numbers, arrays, and objects where truthy values indicate which classes to include. It then returns a deduplicated, space-separated class string that can be applied directly to HTML or JSX className attributes. The library is distributed in multiple formats (ESM, CommonJS, and UMD) so it works well in bundlers, Node environments, and direct tags. Because it has zero dependencies and a stable API, it is widely used in both small projects and large production codebases where bundle size is a concern.