.boton.dos::after {
	content: "";
	width: 100%;
	position: absolute;
	z-index: 1;
	top: 0;
	left: calc(-100% - 80px);
	border-bottom: 80px solid #286cff;
	border-right: 80px solid transparent;
	transition: .4s ease-in-out all;
}

.boton.dos:hover::after {
	left: 0;
}