Contact form - custom inputs, independent validation

What are you most proud of, and what would you do differently next time?

I am satisfied with my custom radio buttons and checkboxes and with the form validation solution in JS.

Validation is done in such a way that the same code (with a small correction) can be used for many forms. Works independently.

What challenges did you encounter, and how did you overcome them?

I definitely had a problem with JS multiplying over time. The best way to do this is to think twice about how something should work rather than rushing in.

Please give me any advice or tips if you notice something that needs to be corrected.