How to hide horizontal rule

Is there a way to hide the horizontal rule that Xwiki seems to put at the top of everypage?
If using SSX, what CSS would I use to say “hide the first hr”?

I guess it’s coming from xwiki-platform/xwiki-platform-core/xwiki-platform-flamingo/xwiki-platform-flamingo-skin/xwiki-platform-flamingo-skin-resources/src/main/resources/flamingo/contentheader.vm at 73b07f8352d1716b9945b577d6e4a3334f058a77 · xwiki/xwiki-platform · GitHub

So you could either customize the skin to override this template or use a SSX, based on HTML you see around that HR (or count the HRs from the top).