.presentation_tile{
	width:400px;
	display:inline-block;
	background-color:#eee;
	position:relative;
}
.presentation_tile_content{
	width:100%;
	pointer-events:none;
}
.slide_tile{
	width:480px;
	display:inline-block;
	position:relative;
	padding:5px;
	box-sizing:border-box;
	opacity:0.5;
}
.slide_tile:hover{
	filter:brightness(80%);
	cursor:pointer;
}
.slide_tile:active{
	filter:brightness(50%);
}
.slide_tile img{
	width:100%;
}
.tooltip{
	width:100%;
	height:100%;
	background-color:rgba(0,0,0,0.2);
	z-index:9000;
	position:absolute;
	top:0px;
	left:0px;
	opacity:0;
}
.tooltip:hover{
	cursor:pointer;
    opacity: 1;
    transition: opacity .25s ease-in-out;
    -moz-transition: opacity .25s ease-in-out;
    -webkit-transition: opacity .25s ease-in-out;
}
.tooltip:active{
	background-color:rgba(0,0,0,0.5);
}
.tile_title{
	font-size:30px;
	position:relative;
	top:40%;
	text-align:center;
	color:white;
	pointer-events:none;
}
@media screen and (max-width : 1280px)  {
	.presentation_tile{
		width:300px;
	}
	.slide_tile{
		width:300px;
	}
}
@media screen and (max-width : 640px)  {
	.presentation_tile{
		width:100%;
	}
	.slide_tile{
		width:100%;
	}
}