invisible middle button in browser scrollbar - force its appearence!
I use Vivaldi in Debian. I use a dark theme for my desktop, with all possible programs - sadly, not all of them respect or use the window manager's theme. Some of them use something different as appearance, but this is rarely, very rarely, good.
In Vivaldi, with most websites, the browser scroll bar is pretty much invisible - or, better saying, it is barely just a white column in the right border of the window!
Look at this screenshot, made right here in Vivaldi forum:
A light grey scroll button to be dragged in a light grey bar. "Thank you! I could not make it more hidden."
In this forum that may not have a dark theme (if it has, please tell me, but i want to have it dark since before logging in), notice that the scroll bar inside the page (where the post is being written) has its colours inverted - so, they are good to be used, dark - and the button has a good colour contrast.
Firefox has a few default basic colours that are used in pages that do not define them - and thus, the default would be usually pure black text, pure white background, pure blue links, purple visited links. I prefer that these colours (the colours chosen in that setting, I mean) always override sites' colours, in most situations. I still use a lot of websites in Firefox, just for this detail! And they are not just simple sites. There are a few which do not behave friendly for this override, but this is another story.
The first step is to remove that horrible white scroll bar we have. Make it use the same theme we see in the rest of the Vivaldi windows, which I have shown, in the screenshot above, in a private window and a normal window. The normal window has the colours of my window manager (I chose them).
One more thing: youtube is a bad website that complete overrides browser's scrollbar. Its scroll bar is thin... it is not hard to grab just because I usually use maximized windows. But for other windows, that kind of bar would be awful. I prefer that no website can do that. If there are people who prefer this liberty for sites, make this a setting we can change, please.