<h1 class="cp_h1title">見出しテキスト</h1>

body {
	counter-reset: titleNum;
}
h1.cp_h1title {
	counter-increment: titleNum;
}
.cp_h1title {
	position: relative;
	padding: .1em .3em .1em 1.5em;
	border-bottom: 1px solid #FFCC80;
}
.cp_h1title::before {
	position: absolute;
	content: counter(titleNum);
	color: #fff;
	font-size: .9em;
	text-align: center;
	top: calc(50% - 0.75em);
	left: 0;
	width: 1.5em;
	height: 1.5em;
	line-height: 1.5em;
	background-color: #FF9800;
	border-radius: 100%;
}