.back2Top{color:#fff;cursor:pointer;z-index:99;visibility:hidden;opacity:0;background-color:#748792b0;border:1px solid #748792;border-radius:5px;padding:15px 25px;font-size:2em;font-weight:700;transition:visibility,opacity .25s linear;position:fixed;bottom:15px;right:15px}.back2Top.show{visibility:visible;opacity:1}