clearfix.css

/*
add the clearfix class to the parent element.
In my case, the border of a div was collapsing into a child button. This was caused by adding the "float": "left" rule to the button
(this occurs even when "clear": "right" is not added)

*/

.clearfix:after {
  content: "";
  display: table;
  clear: both;
}

/*********************************
below is Nicolas Gallagher's micro clearfix hack
********************************/

.clearfix:before,
.clearfix:after {
    content: " ";
    display: table;
}

.clearfix:after {
    clear: both;
}