Your CSS is a mess.
This visualises that mess.
This will render every possible combination of your rules and show you where things look the same.
But you're describing them differently for some reason.
You'll be so embarrassed you'll then fix it.
Clicking elements will delete them.
Delete them from the page.
Then delete those redundant rules from your CSS.
Then profit.
Then create a style guide so it doesn't happen again.
It's okay as other sites have messes, look at one in the dropdown
Then simply add a CSS file to index.html and look at your mess.