If you build things as components as you are supposed to (every backend and frontend framework has been geared around since the late 90s) Your CSS styling should correspond directly to your components (whether they are JS or a MVC partial view). So it should be obvious.

> You need to go digging around in all your stylesheets to figure it out and in most cases actually load up the page and inspect it.

When are you changing CSS and not inspecting the page at the same time? You are going to have to check your work. This doesn't happen if you keep things tidy as you go along. Working in a large team and/or scrum is no excuse for checking-in poor code.