<h1 class="cp_h1title">見出しテキスト</h1>

.cp_h1title{
	border-bottom: solid 4px #4DD0E1;
	position: relative;
	padding: .3em 0;
}
.cp_h1title:after {
	position: absolute;
	content: " ";
	display: block;
	border-bottom: solid 4px #006064;
	bottom: -4px;
	width: 15%;
}