How to attach a css file to the content page...?

Hello,

I am working on my site and noticed that when I try to manually add a stylesheet to a content page it doesnt work. In master pages, all I would need to do is find the "attach stylesheet" in the stylesheet UI and GUI but now when I do that for a content page, it doesnt add. 

I will post photos of what I am saying...

So basically when I try to add stylesheet (in the first red circle...), it doesn't add the code to the second red circle. 

I tried adding it manually but I think my syntax is messed up. Anyone know how to add a stylesheet to this content page...?

Thanks in advance.

Best Regards,

AlphaCr8tive