.window-slider{
    width: 815px;
    height: 515px;
    position: relative;
    left: 50%;
    margin-left: -410px;
    background-color: #000;
    border-top-left-radius: 15px;
    border-top-right-radius: 15px;
    border-bottom-left-radius: 15px;
    border-bottom-right-radius: 15px;
}
.tl-window{
    border: solid 5px #000;
    border-right: solid 2.5px #000;
    border-bottom: solid 2.5px #000;
    border-top-left-radius: 15px;
}
.tr-window{
    border: solid 5px #000;
    border-left: solid 2.5px #000;
    border-bottom: solid 2.5px #000;
    border-top-right-radius: 15px;
}
.bl-window{
    border: solid 5px #000;
    border-right: solid 2.5px #000;
    border-top: solid 2.5px #000;
    border-bottom-left-radius: 15px;
}
.br-window{
    border: solid 5px #000;
    border-left: solid 2.5px #000;
    border-top: solid 2.5px #000;
    border-bottom-right-radius: 15px;
}
.window-slider > div:nth-child(odd){
    float: left;
}
.window-slider > div:nth-child(even){
    float: right;
}
.window-slider > div{
    position:relative;
    width: 400px;
    height: 250px;
    overflow: hidden;
}
.window-slider > div > img{
    position: relative;
    width: 400px;
    height: 250px;
}
.window-slider > div > img:nth-child(n+2){
    display: none;
}