The bookmark bar disappears when the bookmarked link is opened
The bookmarkbar toolbar must be displayed when I open a new tab or even home page and after clicking on the desired link, it will disappear automatically.
Firefox and Chrome do not have this deature in home page.
This feature is not interesting with CSS. This feature must be on Vivaldi itself.
I could have enabled it in Firefox with CSS (userchrome.css), but it was not interesting and annoying, but finally Mozilla realized that it had to put this feature in the Firefox browser itself.