Question [Solved] Remove style css
It's not added by the wpDiscuz plugin side. You can check here wpDiscuz doesn't have such inline classes: https://wpdiscuz.com/demo/
Please deactivate the plugins/theme one by one and check after each deactivation to find the problem maker.
Keep the cache plugin (if you have) deactivated during this testing process.
Don't forget to press Ctrl+F5(twice) on the frontend each time before checking.