Hi, take a look on our extension "modernpninfo", which per animation (1s) centered at the top of the page pops up. Our "modernpninfo" (box) is responsive. We have developed the concept already in use for a long time and tested it in January 2015 for phpBB 3.1.* in the form of an extension. If you take them to use, it must be mentioned that we (still) have not found a way to let them off by the user
The CSS is initially - color - focused on prosilver. The "modernpninfo" (box) is loaded when you receive a new private message, if you have JS allowed into the browser. Advanced to the count of the notification, so you've an additional function.
A modern effect (similar looks like a pop-up-function, but this is not a popup(!)) ..., - just try it, if you like ...
http://www.ongray-design.de/forum/viewt ... 1000#p6537