Primefaces p:tabMenu align p:menuitem to right - css

Question

I'm using Java EE with JDK 1.8, Maven and Primefaces. Regarding the tabMenu of Primefaces I have the following question:
How can I align the last menuitem to the right?
Please see my code below:
<p:tabMenu activeIndex="#{param.i}">
<p:menuitem value="Login" outcome="/Person/PersonLogin.xhtml"
icon="fa fa-sign-in"
rendered="#{!personModel.personLoggedIn()}">
<f:param name="i" value="#{(!personModel.personLoggedIn())?0:99}"/>
</p:menuitem>
<p:menuitem value="Register" outcome="/Person/PersonRegistration.xhtml"
icon="fa fa-user-plus"
rendered="#{!personModel.personLoggedIn()}">
<f:param name="i" value="#{(!personModel.personLoggedIn())?3:95}"/>
</p:menuitem>
<p:menuitem value="#{personModel.usedAccount.balanceFormatted}"
outcome="/Overviews/TransactionOverview.xhtml"
style="float:right; margin-right: 30px; #{personModel.usedAccount.balance >=0 ? 'color:green;' : 'color:red;'}"
rendered="#{personModel.personLoggedIn()}">
<f:param name="i" value="#{(personModel.personLoggedIn())?123:94}"/>
</p:menuitem>
</p:tabMenu>
This code snippet style="float:right; margin-right: 30px; #{personModel.usedAccount.balance >=0 ? 'color:green;' : 'color:red;'}" in the last menuitem still doesn't align it on the right side:
Currently the output is the following:
while it should look like this:

Answer 1

I have just checked the css that primefaces used. And I see that your css code is used for <a> element instead of outer <li> element. When I manually add your css to outer <li> element, it is working as you want. You need to find a way to add your css to outer <li>
Or, you may use
<p:panelGrid columns="2" layout="grid" columnClasses="ui-grid-col-10,ui-grid-col-2>
first element your <p:tabMenu> element without last <p:menuitem>
and second one can be a <p:commandLink> element
<p:panelGrid columns="2" layout="grid" columnClasses="ui-grid-col-10 tabMenucssclass,ui-grid-col-2 commandlinkcssclass>
<p:tabMenu></p:tabMenu>
<p:commandLink></p:commandLink>
</p:panelGrid>
Check out primefaces panelGrid element
UPDATE - This is not for score, just for answer you should accept #Kukeltje answer
.flo .ui-tabmenuitem:last-child{float: right;}
<p:tabMenu class="flo"></p:tabMenu>

Answer 2

For me the following works (tested in the PF showcase on 6.0.x)
.ui-tabmenuitem:last-child {
float: right !important;
}
Although it is better to not use !important and see if adding a styleClass to the menuItem or the tabMenu and use that in your selector works to (no time to try, sorry).
Update:
As #mismanc and OP found out, styleClass or related is not supported on the tabMenu but a class is. So if you do not want this on every tabmenu
<p:tabMenu class="flo">
...
</p:tabMenu>
and use the class in the selector
.flo .ui-tabmenuitem:last-child {
float: right;
}