Using Chrome Inspect
I use Chrome as my default browser especially when working in WordPress.
>Appearances> Additional CSS> then right click and open Chrome Inspect to see the html and CSS for each element. This is how I see what CSS is impact the look of a page. Then I can modify the CSS with the Additional CSS window.
From the Chrome browser, you can Inspect any page you pull up in the browser to see the inner workings of the HTML and CSS.