The next HTML is produced by Joomla 1.7 for that menu of the site I am focusing on:

<ul class="menu-tabbed-horiz">

<li class="item-435 current active parent">
    <a class="firstmenuitem" href="/joomla/" >Home</a>
</li>
<li class="item-467">
    <a href="/joomla/index.php/menu2" >Menu 2</a>
</li>
<li class="item-468">
    <a href="/joomla/index.php/memu3" >Menu 3</a>
</li>

</ul>

Via CSS, I am styling this menu. For instance, I style recption menus item the mouse is hanging over such as this: .menu-tabbed-horiz a:hover. The active it's possible to be styled like so: .menu-tabbed-horiz .current a.

This works without problem, however I must style a food selection in a different way when it's the present one and hovered on than when it's just hovered on. Something similar to .menu-tabbed-horiz a:hover && !.current, but that clearly doesn't work.

Any suggestions could be appreciated, Fabian

If I have understood your question properly, then you are searching for something similar to this:

.menu-tabbed-horiz .current a:hover { /*Hovered and current*/ }
.menu-tabbed-horiz a:hover { /*Hovered (all)*/ }

This will work since the first selector is much more specific compared to second and can therefore be relevant to elements with .current rather than the 2nd selector.

Here is a working example of the aforementioned code.

You cannot do that type of factor directly. The answer would be to define the "non-current" style for .menu-tabbed-horiz li, and also the "current" style for .menu-tabbed-horiz li.active.

The 2nd style is much more specific compared to first, so it will require priority whenever each style can be found. The very first style is going to be requested all .menu-tabbed-horiz elements that not have the .current class.