How can I apply a specific style to the first paragraph of the page? Is it possible?

Something like this:

[first-page-p-selector] p { color: #f00; }

The first paragraph of each page? Unfortunately this is not yet possible, there is no selector for this in CSS, to select things based on where they appear in the output. Is there some way of identifying the paragraphs you wish to select based on their position in the input document instead?

I was doing that but as I change the text I have to go through all those paragraphs and reassign the class name. I just wanted something more automatic.

I'll keep doing the manual assignment.