@charset "utf-8";
/* CSS Document */
.box {width: 680px; margin: 40px auto; display:flex; flex-wrap:wrap;}

.season-box {
	width: 330px; 
	height: 214px;  
	border-radius: 5px;
	display:block;
	margin:5px;
	background-size:100%; 
	background-repeat:no-repeat;
	opacity: .5;
	transition: opacity 2s; 
}
.season-box:hover {opacity: 1.0;}
.winter {background-image: url("images/winter.jpg");}

.spring {background-image:url("images/spring.jpg")}

.summer {background-image: url("images/summer.jpg")}

.fall {background-image:url("images/fall.jpg")}