CSS clearfix

.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%;
}

http://www.webtoolkit.info/css-clearfix.html