.biografias{
	width: 100%;
	margin-bottom: 20px;
	
}

.titulo_biografias{
	text-align: center;
	font-size: 2em;
	color: orange;
	margin-bottom: 70px;
}
.Autores{
	width: 95%;
	margin: auto;
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	background-image: url(bibliografia.jpg);
	background-repeat: no-repeat;
    background-size: cover;
}

.img_autores{
	margin: 10px;
	-webkit-perspective: 800;
	perspective: 800;

}

.autor{
	width: 200px;
	height: 250px;
	background: orange;
	position: relative;
	transform-style:preserve-3d;
	transition:.7s ease;
	/* aplicar sombras */ 
	-webkit-box-shadow:10px 10Px 15px -5px rgba(0,0,0,0.65);
	-moz-box-shadow:10px 10px 15px -5px rgba(0,0,0,0.65);
	box-shadow:10px 10px 15px -5px rgba(0,0,0,0.65);
}

.arriba, .abajo{
	width: 100%;
	height: 100%;
	position: absolute;
	top: 0;
	left:0;
	--webkit-visibility: hidden;
	backface-visibility: hidden;
}

.img_autores:hover .autor{
	transform: rotateY(180deg);
}

.arriba{
	width: 100%;
}

.abajo{
	transform: rotateY(180deg);
	display: flex;
	justify-content: center;
	align-items: center;
	text-align: center;
	color: #fff;
}


.img_biografias{
	height: 250px;
	width: 200px;
	object-fit: cover;
	object-position: center;
}

.link-biografias{
	text-decoration:none;
	color: white;
}
.main-footer{
	background: cornflowerblue;
}

@media screen and (min-width:770px){
	.biografias{
		margin-bottom: 40px;
	}
}
@media screen and (min-width:1024px){
	.biografias{
		margin-bottom: 70px;
	}
}