#back-to-top{position:fixed;bottom:30px;right:30px;background:#ff4101;color:#fff;font-size:22px;text-align:center;line-height:40px;width:40px;height:40px;border-radius:50%;box-shadow:0 4px 6px rgba(0,0,0,0.2);cursor:pointer;z-index:999;opacity:0;visibility:hidden;transition:all 0.3s ease-in-out}#back-to-top:hover{background:#333}#back-to-top.show{opacity:1;visibility:visible}