.marker {width:0; height:0;}
.marker  span {
	display:flex;
	justify-content:center;
	align-items:center;
	box-sizing:border-box;
	width: 30px;
	height: 30px;
	color:#fff;
	background: #693;
	border:solid 2px;
	border-radius: 0 70% 70%;
	box-shadow:0 0 2px #000;
	cursor: pointer;
	transform-origin:0 0;
	transform: rotateZ(-135deg);
}
.marker b {transform: rotateZ(135deg)}