Vivaldi is awesome browser, and I really like it. The UI is really good, but one thing that I always like to see is Blur Effect. It would be nice if you make menu bar with blurred background. Also, a nice blur on the panel would be nice
I really hope I'll see something like that in the future!
If you think a feature is useful and missing in Vivaldi, please make a request.
How to make a feature request for Vivaldi
If you think your problem can be solved by a missing feature, please add a request at https://forum.vivaldi.net/category/48/features-requests in the corresponding thread for your browser version.
Add one line in bold as a short title for the feature and 2-3 lines to describe the wanted feature.