.btn-floating {
    width: 0px;
    height: 0px;
    border-style: solid;
    border-width: 50px 86.6px 50px 0;
    border-color: transparent #076591 transparent transparent;
}

#picture-slides {
    margin-left: auto;
    margin-right: auto;
    height: 200px;
    width:  600px;
}

#btn-left {
    margin-right: 100px;
    margin-bottom: 100px;
}