Is there a way to modify the css for one class when hovering on an element from another class using only css ?
Something like:
.item:hover .wrapper {
Provided .wrapper is inside .item, and provided you're either not in IE 6 or .item is an a tag, the CSS you have should work just fine. Do you have evidence to suggest it isn't?
EDIT:
CSS alone can't affect something not contained within it. To make this happen, format your menu like so:
and your CSS like this:
.menu .menu {
display: none;
}
.menu .menuitem:hover .menu {
display: block;
float: left;
// likely need to set top & left
}