.m-back-top { position: fixed; right: 40px; bottom: 40px; transform: scale(0); transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1); -webkit-tap-highlight-color: rgba(0, 0, 0, 0);}.m-back-top .m-button[back-top-cover] { width: 40px; height: 40px;}.m-back-top .m-button[back-top-cover] .m-icon { font-size: 22px;}.m-back-top--active { transform: scale(1);}