.show-img{
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    position: fixed;
    top: 0;
    display: none;
    z-index: 100;
}

.show-img img{
    position: absolute;
    left: 0;
    right: 0;
    margin: 0 auto;
    top: 200px;

}