原文地址如下：
http://www.webtoolkit.info/css-clearfix.html
See also:
http://www.codecto.com/2011/02/css-clearfix-float/
CSS clearfix
The problem happens when a floated element is within a container box, that element does not automatically force the container’s height adjust to the floated element. When an element is floated, its parent no longer contains it because the float is removed from the flow. You can use 2 methods to fix it:
{clear: both;}
clearfix
Once you understand what is happening, use the method below to “clearfix” it.
DEMO
Source code for webtoolkit.clearfix.css
.clearfix:after {
content: “.”;
display: block;
clear: both;
visibility: hidden;
line-height: 0;
height: 0;
}
.clearfix {
display: inline-block;
}
html[xmlns] .clearfix {
display: block;
}
* html .clearfix {
height: 1%;
}
以下是另外一种 clearfix 的写法，来处 jQuery UI:
.clearfix:before, .clearfix:after { content: “”; display: table; }
.clearfix:after { clear: both; }
.clearfix { zoom: 1; }
