@charset "utf 8";

.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: 0.5;
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");}