I am using a free wordpress theme ,named Pitch (http://siteorigin.com/theme/pitch/) . I redesign the menu bar , so that the background of first element of the menu bar will show an image (the logo). To do so , I just add a simple block of code
ul#mainmenu-menu li.menu-item:first-child {
background:url(images/logo.png) no-repeat ;
text-indent:-9999px;
width:200px;
border:none;
}
ul#mainmenu-menu li.menu-item:first-child a:hover {
background:none;
}
But the problem is , that image also appear in first element of the dropdown item too . Like the image

What did I do wrong , How can I fix this ?
Here is the complete CSS code http://pastebin.com/edsYrqWF
Plz help me out