.btn.btn-fab {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: inline;
    border-radius: 50%;
    z-index: 999;
    height: 75px;
    width: 75px;
}

.btn-fab.dropup .dropdown-menu {
    max-width: 200px;
    position: fixed;
    bottom: calc(20px + 75px + 10px);
    left: calc(100% - 180px);
}
.btn-fab.dropup .dropdown-menu li {
    margin: 0 10px;
}

.btn-fab.dropup .dropdown-menu li:not(:last-child) {
    margin-bottom: 5px;
}