hey Sascha T. you can not adjust the top part unfortunately.
However, there is a hack. You can use that Code (CSS) to hide the top section and then try to incorporate/create a section in your post editor and have multiple link including read online.
Keyur is right, just hide the header and make your own. To hide it, just put this CSS in the box (the header’s class is helpfully named f lol.
.f { display:none;}