Don't you confused by tabs?
Don't you think the inactive tabs aren't distinct? They're like all have same background color. Personally I can't count number of tabs right of active tab (especially new unloaded tabs - unless by their icons)
This makes me a little crazy as well. I look forward to Vivaldi adding greater visual delineation between inactive tabs, so that I can apprehend which is which, and I can click on the right one with less effort put into visual inspection before I move my mouse, and with fewer errors.