inline-block <ul> to get rid of some `width:` properties

In the case of a drop-down menu, it would be really cool to inline-block the 3rd (and higher)-level <ul> in order to vertical-align them with their corresponding <li>/<a>.
This CSS property is mostly support nowaday.
Basic sample:
<a>link</a><ul style="display: inline-block"><li>list item</li></ul>

The benefit is : no hardcoded width in order to space <ul> from <a> anymore.
So every 3rd-level <ul> is always correctly aligned and stuck to the 2nd-level <li> whatever the <li> (calculated) width is.
As the width is no more hardcoded, menus entry with longer text length are no more wrapped on two lines.
(that's the real benefit).

In the case of an override of the current CSS, it means, at least :

ul.nice-menu-down ul li {
  /* resets the width value for every <li> of the 2nd level and higher */
  width: auto;
}
ul.nice-menu-down ul,
ul.nice-menu-down ul li.menuparent {
  /* containers adapted to the (inlined) content;
     see https://developer.mozilla.org/en/CSS/max-width */
  width: -moz-max-content;
}
/* restore the default <a> status : inline */
ul.nice-menu-down ul a {
  display: inline;
}
/* inline-block the <ul> */
ul.nice-menu-down ul ul { 
  display: inline-block;
  top: auto;
  left: auto;
  position: relative;
}