.back-to-top{background-color:#000;border:none;border-radius:8px;bottom:30px;box-shadow:0 4px 8px rgba(0,0,0,.2);color:#fff;cursor:pointer;display:block;font-size:16px;padding:12px 18px;position:fixed;right:30px;transition:opacity .3s ease;z-index:1000}.back-to-top:hover{background-color:#333}