* { padding: 0; margin: 0; }
body{
	font-family: arial; 
	font-size: 12px;
} 
header {
	display:block;
	position: fixed; 
	width: 100%; 
	height: 80px;
	left: 0; 
	top: 0;
	z-index: 999;
	background-color: #fff;
	border-bottom: 1px solid #006699;
	padding:10px;

}
header > h3 {
	margin:10px;
	padding:5px; 
	border-radius: 5px; 
	border: 1px solid #ccc;
	background-color: #efefef; 
}
header > nav {
	margin:5px 10px;
	padding:5px; 
}
header > nav > ul {
	list-style: none; 
}

header > nav > ul > li {
	display: inline-block; 
}

header > nav > ul > li > a {
	margin: 10px;
	padding: 10px;
	background-color: #006699; 
	color: #fff;
	border-radius: 5px; 
	text-decoration: none; 
	font-weight: bold; 
}

header > nav > ul > li > a:hover {
	background-color: green; 
} 

section {
	padding-top: 100px;
}

article {
	margin:10px; 
	padding:5px; 
	border: 1px solid #ccc;
	border-radius: 5px;
}

article h4 {
	padding:10px;
	background-color: #aaa; 
	font-weight: bolder;
	color:#fff;
}

article p {
	margin:10px;
}

article > ol {
	margin:35px;
}

article > ol > li {
	margin:10px;
	padding:5px;
	border-bottom: 1px solid green; 
}

.pre{
	width: 70%;
	margin: 10px auto;
	overflow: auto; 
	height: 250px;
	display: block; 
	background-color: lightgrey; 
	padding: 5px;
	border: 1px solid #006699;
}