<h1>見出しテキスト</h1>

h1 {
	position: relative;
	padding: .3em;
	background-color: #B2EBF2;
	color: #0097A7;
}
h1::before,
h1::after {
	content: '';
	position: absolute;
	border-style: solid;
	border-width: 0 15px 15px 0;
}
h1::before {
	top: 100%;
	left: 0;
	border-color: transparent #0097A7 transparent transparent;
}
h1::after {
	top: -15px;
	right: 0;
	border-color: transparent transparent #0097A7 transparent;
}