codepawan-dev/Temperature-Calculator ? reverse-engineered prompt

Build me a simple desktop temperature converter in Java.

It should let me enter a temperature and convert Celsius to Fahrenheit or Fahrenheit to Celsius with a clear button to reset things. I also want a light mode and dark mode switch so the app feels nice to use in both themes. Keep the interface clean and easy to understand, with a small window, a title, and obvious labels for the input and result.

I’d like it to look polished enough to match a basic screenshot style app, not just a plain form. If you need to check any current Java GUI best practices or docs online, go ahead and do that. Please make sure the app runs from one main Java file and the conversion works correctly in both directions.