How can I add PDF to custom post type?

Right, I think I misunderstood the question, so leaving original answer underneath (may help you, or someone else). What im assuming here is that custom css is unique for each custom post. Method 1. Minimal PHP because I'm lazy, and you won't learn if I do it all for you! Insert a style tag before the custom post. Add your custom css in the style tag but, wrap it in a unique ID (should go without saying, these are HTML IDs after all). Then, add the unique ID to the root (or whatever element you need the custom css applied to) element of the custom post.

Method 2. This involves concatenating the custom CSS and putting it in a style tag of the elements you need (less neat). Original Answer Steps. 1) Create a custom post class in your case. E.g.. .my-custom-post { // set whatever you'd like } 2) Create php logic to add the custom class if custom post. E.g.. Note. I would do it using OOP and would have a class that represents a post. I'd then use methods to manipulate the post. This is how I'd handle the OOP logic. is_customType === true){ $post->addClass('my-custom-post'); } ?>