CSS Code Refactoring. Are there any tools/mechanisms/services that can make css/less/sass refactoring easier/improved?

Question

css

In general, for several years, css in the project has swollen to the point of obscenity, a task has been received for css code refactoring.
What I see as the main problem: for many years, if necessary, styles were stupidly overwritten, now in the inspector there are very long footcloths with styles overwritten and crossed out many times.
Are there any tools or services in nature that could somehow help simplify this process, since it’s still an occupation to clean up more than one thousand lines with your hands and head.
Well, or - who went through this, plz share your experience in the comments, how did you do it, where did you start, how did you cope? In my particular case, all the code is in less, I don’t know if there are any specifics here, what to pay special attention to.