1. 将网页或元素居中
HTML：
<div class="wrap">
</div><!-- end wrap -->
CSS：
.wrap { width:960px; margin:0 auto;}
2.Sticky Footer (让页脚永远停靠在页面底部，而不是根据绝对位置)
HTML：
<div id="wrap">
<div id="main" class="clearfix">
</div>
</div>
<div id="footer">
</div>
CSS：
* { margin:0; padding:0; }
html, body, #wrap { height: 100%; }
body > #wrap {height: auto; min-height: 100%;}
#main { padding-bottom: 150px; } /* must be same height as the footer */
#footer {
position: relative;
margin-top: -150px; /* negative value of footer height */
height: 150px;
clear:both;}
/* CLEAR FIX*/
.clearfix:after {content: ".";
display: block;
height: 0;
clear: both;
visibility: hidden;}
.clearfix {display: inline-block;}
/* Hides from IE-mac */
* html .clearfix { height: 1%;}
.clearfix {display: block;}
/* End&nb
