Cannot close Project CSS window

I can open the Project CSS file from the Project menu but I cannot close it.
What’s the secret?

Close the tab for it. It will be in the tab bar across the top of the Code Window.

The only way to close the tab for it is to click on another code window tab.
Why not just put a Close X beside it like all the other code windows.

Okay, I see. It opens and closes at the same time as when you click on Project Properties and Global Code. That’s weird.