.scroll-to-top {position: fixed;bottom: 20%;right: 20px;color: #fff;border: none;display: none;cursor: pointer;transition: opacity .3s, transform .3s;padding: 0;background: #ffffff;border-radius: 50%;height: 45px;width: 45px;}
.scroll-to-top.show {display: flex;opacity: 1;}