hvordan: hover reagere på større felt

Kode 

@charset "utf-8";

*	{
	margin: 0px;
	padding: 0px;
}

body {
	text-align: center;
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 11px;
}
img{
	border:none;
}
#header_home {
	height: 266px;
	width: 1025px;
	margin:0 auto;
	background:transparent url(grafik/ot.jpg) no-repeat left top;
}
#header_er{
	height: 266px;
	width: 1025px;
	margin:0 auto;
	background:transparent url(grafik/er.jpg) no-repeat left top;
}

#wrapper {
	background: red;
	width: 1025px;
	margin:0 auto;
	text-align: left;
}
#header_home ul li a {
	color: white;
	margin-top:16px;
	text-decoration: none;;
	line-height:16px;
	display:block;
	padding: 0 20px 0 20px;
	background-color: black;
	text-align: right;
}
#header_home ul li a:hover{
	color: black;
	text-decoration: none;
	background-color: #FFEC00;
}
#header_home ul {
	width: 100px;
	height: 20px;
	list-style-type: none;
	float:left;
}
#header_home ul li {
	width: 200px;
	height: 20px;
	margin:0 auto;
	list-style-type: none;
	float:left;
}