Is it possible to format the font used for custom navigation links?

I don’t know if this is the better way (but it works):

.list-controls .nav-pills .active a[href="/bookmarks"] {
    font-style: italic;
}

However you can remove those lines from CSS:

border-radius: 0px;
border-bottom: 0px solid !important;

you don’t need them (they are relative to my specific case).