正确使用CSS:在特定容器中不排除元素

I am styling a series of pages of which I have no control of their markup, and it is presenting some unique challenges. The styles are based on a design mockup that I was given and therefore there are instances of- for example- h2 elements that must look different than other particular h2 elements in order for the design to be adhered to. I am styling a series of pages of which I have