<h1 class="cp_h1title">見出しテキスト</h1>

.cp_h1title {
	position: relative;
	padding: .3em;
	background-color: #00897B;
	color: #ffffff;
}
.cp_h1title::after {
	position: absolute;
	top: 0;
	right: 0;
	content: '';
	width: 0;
	border-width: 0 16px 16px 0;
	border-style: solid;
	border-color: #fafcfc #fafcfc #B2DFDB #B2DFDB;
	box-shadow: -1px 1px 2px rgba(0, 0, 0, .1);
}