How do I apply a custom css style to a chapter title?

How do I apply custom css styles to chapter titles? In the compiler, I don’t any option to associate a particular CSS style to a particular title.

Does anyone know the answer to this question? I still can’t figure out how to do this? Do I just append custom CSS in the compiler? If so, which CSS selector do I specify for the heading 1 and heading 2 styles? Thanks.

And other thing, I created a new project from scratch and I now see the “bordered title” style defined in the styles list of the compiler for epub but not in the main project of the editor. I didn’t see this in my previous old scrivener version project that I opened up in scrivener 3. What is going on? Any insights would be appreciated. Thanks.