* {
	-moz-box-sizing: border-box;
	-webkit-box-sizing: border-box;
	box-sizing: border-box;
}
html, body {
	margin: 0;
	padding: 0;
}
body {
	color: #222;
	font: 16px/1.5 Helvetica, Arial, sans-serif;
}
h1, h2, h3, p, pre, ul {
	margin: 0;
	padding: 0;
}
h1 {
	font-size: 48px;
	line-height: 1;
	margin-bottom: 1em;
}
h2 {
	font-size: 24px;
	line-height: 1;
	margin-bottom: 1em;
}
h3 {
	font-size: 16px;
	line-height: 1;
	margin-bottom: 1em;
}
p, pre, ul {
	margin-bottom: 2em;
}
pre {
	background: #fefefe;
	border: 1px solid #dedede;
	overflow-x: auto;
	padding: 2em;
}
ul {
	margin-left: 1em;
}

/* 主要代码部分 */
#nav {left: 20px;list-style: none;margin: 0;position: fixed;top: 20px;}
#nav li {margin-bottom: 2px;}
#nav a {background: #ededed;color: #666;display: block;	font-size: 14px;padding: 5px 10px;text-decoration: none;text-transform: uppercase;}
#nav a:hover {background: #dedede;}
#nav .current a {background: #666;color: #ededed;}
#container {margin: 0 auto;	width: 800px;}
.section {border-bottom: 5px solid #ccc;min-height: 60vh;padding: 50px 20px;}
.section p:last-child {	margin-bottom: 0;}