update: I have added your code to the custom css.
The attached images show you the ‘before’ and ‘after’ situation. As you can see, the grey line has disappeard.
But the yellow line is still there.
What code is needed if I want that one gone too?
I have added your code to the customizer, but since then I can not reach my site anymore.
I now get an HTTP error 503 (service unavailable).
On internet I can find that this might be caused by a plugin or a theme at my WordPress website. I have only made a change in my theme (added the code you suggested), nothing else. And now I get this error message.
Thank you for looking into it. My site url is: http://www.karinvandenbosch.nl
This site is still under construction. I try, with the circumference theme, to make it look good, but that’s still some work 🙂