XF 2.2 How to hide specific prefixes on all widgets ?!


im looking for an way to hide a specific prefix on my widgets like "top resources" / "last resources" and so on.
The story is that i have multiple prefixes for my resources and i want to have one specific prefix on top that is much bigger as the other ones bellow.

Here an example image:

The problem now is when i use this settings for the prefix to make it on the top and bigger as the others:

(prefixes via extra.less)

.prefixpremium {
    font-size: 15px;
    font-weight: bold;
    line-height: 26px;
    padding: 0 80px;
    vertical-align: middle;

then it is big on all widgets and also in the threads..
and this looks absolute ugly and ****ed up (sorry for this words)

So how to hide this specific prefix on all widgets ? Does anyone have an idea how to handle that quick and easy ?
Someone say i need to use something like this here:

#js-SideNavOcm > div.uix_sidebar--scroller.is_stuck > div:nth-child(2) > div > div:nth-child(2) > div > ul > li:nth-child(3) > div > div.contentRow-main.contentRow-main--close > a > span.label.label--pre-readme {
    display: none;

But this is not working when i change the prefixname to my name.

Widgets are more important then hiding it in the threads.
That is a second story and can be done later. Important for me is to hide this specific top prefixes on the widgets.