html, body{
    margin:0;
    padding:0;
    height:100%;
    background:url(../img/fon.jpg);
    background-size: cover;
    display: flex;
    justify-content: center;
    align-items: center;
}

a{
    display:inline-block;
    position:relative;
}

a img{
    display:block;
    max-width:100%;
    max-height:100%;
    cursor:pointer;
    user-select: none;
}

.click {
    display: none;
    width: 100%;
    min-height: 100%;
    background-color: rgba(0,0,0,0.5);
    overflow: hidden;
    position: fixed;
    top: 0px;
    z-index: 100;
}