Altered theme CSS files when installing

hello support,

Im hoping you can help. I installed this plugin and it alternate the css files of my frontend theme and it also looks like some of the backend css styles were altered. I removed the plugin and our sites does not look the same as it did prior to installing. Can you please tell us if there any files outside of the plugin folder that modified; in this case css files?

Website: https://www.myvipclubs.com/city/new-york/listing/asian-art-museum/

Thank you in advance
Peter

https://www.ads-software.com/plugins/query-monitor/