Hi,
What’s happening here is most likely a browser strictness issue with Mozilla Firefox, not that your calculator logic is fundamentally broken. Chrome tends to “forgive” loose JavaScript—like using raw input values without parsing or handling empty fields—while Firefox is much stricter. So if your code is directly using something like input.value in calculations, Firefox may treat it as NaN (not a number), which silently breaks the output and makes it look like nothing is working.
The fix is usually simple but important: make your JavaScript more explicit and defensive. Always convert input using parseFloat(), check for NaN, and ensure your script runs after the DOM is fully loaded. Also use the "input" event instead of "change" for consistent behavior. In short, don’t rely on the browser to guess what you mean—tell it clearly. Once you tighten that up, your calculator should behave the same across all browsers, including Firefox.
Regards
