*, *:before, *:after{
box-sizing: border-box;
}

body{
display: flex;
flex-wrap: wrap;
justify-content: center;
align-items: center;
}
img{
display: block;
margin: 8px;
border: 2px solid black;
box-shadow: 4px 4px 8px;
border-radius: 5px;
max-width: 70%;
height: auto;
filter: grayscale(1);
}
img:hover{
    filter: grayscale(0);
    transform: scale(1.2);
    z-index: 10;
    transition: .4s transform ease-in-out;
}