I'm looking to create a custom input box on Fandom and am open to using whatever tools are available—whether it's Wikitext, JavaScript, Lua, or CSS. Specifically, I want to build a calculator that calculates and displays a percentage (formatted as 0.00%) based on the numerical difference between two user-provided values.
Could anyone provide guidance on how to implement this, considering Fandom’s limitations and supported features? I’d appreciate recommendations on the best way to achieve this functionality.