align menu to the right

hi
sorry to raise this for the 100th time but still:

I’m trying to align the lang flags in the menu bar to the right.
i’m using this custom css code in the twentytwelve theme:

.lang-switch {
float:right;
}
.lang-item {
display:inline;
}

but this doesnt work. any idea?

https://www.ads-software.com/plugins/polylang/