How to split the categories into sections with titles?

[manuel (Manuel Kostka)]

@manuel

body [data-category-id="1"]:before {
    content: "Projects";
}

You just need to be more specific with your style declaration. The code snippet declares styles anywhere on the body element. To change that, inspect the element you want to adjust with your browser tools and replace body with a more specific declaration, e.g:

#main-outlet .category-list {
  [data-category-id="1"]:before {
     content: "Projects";
  }
}