Clear floating elements

grid.css

/* `Clear Floated Elements
----------------------------------------------------------------------------------------------------*/

/* http://sonspring.com/journal/clearing-floats */

.clear {
  clear: both;
  display: block;
  overflow: hidden;
  visibility: hidden;
  width: 0;
  height: 0;
}

/* http://www.yuiblog.com/blog/2010/09/27/clearfix-reloaded-overflowhidden-demystified */

.clearfix:before,
.clearfix:after {
  content: '\0020';
  display: block;
  overflow: hidden;
  visibility: hidden;
  width: 0;
  height: 0;
}

.clearfix:after {
  clear: both;
}

/*
  The following zoom:1 rule is specifically for IE6 + IE7.
  Move to separate stylesheet if invalid CSS is a problem.
*/

.clearfix {
  zoom: 1;
}