Interesting to see major sites with CSS issues like that, with the country code ("GB" for me, in the UK) added the width on the logo box isn't wide enough.

#yt-masthead #logo-container { margin-right: 20px; }

is a hacky fix.

They appear to be using position:absolute to get cheap vertical alignment to put the GB at the top, but it removes from the flow and so gets overlaid. "vertical-align:top" works, it seems, so I'm curious why they've not used that instead?