* {
    box-sizing: border-box;
}
body{
    margin: 0;
    background-color: #cfcccc;
}
 
.container{
    width:100%;
    min-height: 100vh;
    
 
}
 
main{
    display: flex;
    justify-content: space-around;
    align-items: center;
    width: 100vw;
    height: 100vh;
   flex-wrap: wrap;
}
 
.box {
    position: relative;
    width: 300px;
    height: 300px;
    overflow: hidden;
    border: 15px solid grey;
    border-radius: 15px;
    margin: 33px;
}
 
img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: all linear 0.7s;
}
 
.hover_img {
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
}
 
.box:hover img {
    opacity: 0;
 
}
 
.box:hover .hover_img {
    opacity: 1;
 
}