<div class="wrap">
  <div class="col">
    <p>Column1</p>
  </div>
  <div class="col">
    <p>Column2</p>
  </div>
</div>
.wrap {
	/zoom: 1;
}
.wrap:after {
	display: block;
	clear: both;
	height: 0;
	visibility: hidden;
	content: ".";
}
.col{
  width: calc( (100% - 30px) / 5 * 2 );
  float: left;
}
.col:last-child{
  width: calc( (100% - 30px) / 5 * 3 );
  float: right;
}

External CSS

  1. https://www.ibnet.ne.jp/column/web/201012/screen.css

External JavaScript

This Pen doesn't use any external JavaScript resources.