How to Check for Case-Insensitive Substrings in Go: Best Practices for 'golang string fold contains'?

Thanks, everyone! 🙌 I tried the `strings.Contains` + `ToLower` approach, and it worked perfectly for my use case.

I also checked out the `golang.org/x/text/cases` package, but it felt a bit heavy for what I needed. The regex solution is cool, but I’ll save that for more complex scenarios.

One follow-up: Has anyone tested the performance difference between `ToLower` and a custom loop for large strings? Just curious if it’s worth the extra effort.

Thanks again, y’all are awesome! 🚀