clearfix_hack

.clear:after { /* expands collapsed parent to clear its height past its floating children */

	content: " "; /* adds html text of period symbol (:after) all opther children inside the parent with is .clear:after class applied to it. */

	display: block; /* set newly created content: to display block */

	clear: both; /* sets the '.' content to clear past all of the floating children giving a height reference. */

	visibility: hidden; /* make the '.' content invisible. */

	line-height: 0; /* make sure it has no text line-height */

	height: 0; /* make sue it has no physical height */
}