How to give width to notification in percentage

[jsUser1]

How to give width to notification in percentage

How can I apply width in percentage to the notifications, which is supposed to be shown at top of the screen, something like shown in the attached picture.

In the previous version, there was a .notification class, through which I was able to give inline CSS for width in percentage like this:
.rnc__notification-container--top-center .notification {
width: 100% !important;
}
But now this class has been removed. I don't want to give width in px.

[teodosii]

I've added it back in 3.4.1, use .rnc__notification class name.

[jsUser1]

Thank you so much.... :-)