I googled "css specificity" and it autocompleted "calculator", which led me to https://specificity.keegan.st/ https://specificity.keegan.st/. You can paste in

I googled "css specificity" and it autocompleted "calculator", which led me to https://specificity.keegan.st/ https://specificity.keegan.st/. You can paste in a series of selectors (getting new boxes by clicking "duplicate"), then hit "Sort by specificity".