<h1 class="cp_h1title">見出しテキスト</h1>

.cp_h1title {
	position: relative;
	padding: .3em;
}
.cp_h1title:after {
	content: "";
	position: absolute;
	left: 0;
	bottom: 0;
	width: 100%;
	height: 4px;
	background: repeating-linear-gradient(-45deg, #FF7043, #FF7043 2px, #fff 2px, #fff 4px);
}