.arrow_box {
	position: relative;
	background: #2d2d2d;;
}
.arrow_box:after {
	bottom: 100%;
	border: solid transparent;
	content: " ";
	height: 0;
	width: 0;
	position: absolute;
	pointer-events: none;
}

.arrow_box:after {
	border-color: rgba(0, 0, 0, 0);
	border-bottom-color: #2d2d2d;;
	border-width: 15px;
	left: 50%;
	margin-left: -40px;
}