#container{
    display:flex;
    width:50%;
    margin:100px auto;
}

#images{
    width:300px;
    height:300px;
    overflow:hidden;
    position:relative;
    margin:auto;
}
#images img{
    position:absolute;
    width:100%;
    height:100%;
}

.button{
    align-content:center;
    width:25px;
}

.active{
    z-index:4;
}
.last{
    z-index:3;
}