We are upgrading Pega 4 to Pega 7. Quite lot of CSS styles are custom coded in Text files. When I inspect an element, I see the CSS for the element in the browser. For ex.,

element.style {
}
.groupTitleBarIconSPANExpanded {
    display: block;
    background-image: none;
    width: 30px;
    background-repeat: no-repeat;
    background-position: 6px 0px;
}

Is there a way to quickly identify which text file, the above CSS is picked up from? For ex., the above code comes from user_work_form.css text file. To find that, I had to do manual search in the designer studio looking for this class groupTitleBarIconSPANExpanded. I am looking for an easy way to find the information.