hacer un menu por pestañas css code example

Example: pestañas dentro de una pagina web php

ul.tabs {
	margin: 0;
	padding: 0;
	float: left;
	list-style: none;
	height: 32px; /*--Set height of tabs--*/
	border-bottom: 1px solid #999;
	border-left: 1px solid #999;
	width: 100%;
}
ul.tabs li {
	float: left;
	margin: 0;
	padding: 0;
	height: 31px; /*--Subtract 1px from the height of the unordered list--*/
	line-height: 31px; /*--Vertically aligns the text within the tab--*/
	border: 1px solid #999;
	border-left: none;
	margin-bottom: -1px; /*--Pull the list item down 1px--*/
	overflow: hidden;
	position: relative;
	background: #e0e0e0;
}
ul.tabs li a {
	text-decoration: none;
	color: #000;
	display: block;
	font-size: 1.2em;
	padding: 0 20px;
	border: 1px solid #fff; /*--Gives the bevel look with a 1px white border inside the list item--*/
	outline: none;
}
ul.tabs li a:hover {
	background: #ccc;
}
html ul.tabs li.active, html ul.tabs li.active a:hover  { /*--Makes sure that the active tab does not
        listen to the hover properties--*/
	background: #fff;
	bo        its content--*/
}rder-bottom: 1px solid #fff; /*--Makes the active tab look like it's connected with