.back-to-top-btn{animation:slideIn .5s forwards}@keyframes slideIn{0%{transform:translateY(20);opacity:0}to{transform:translateY(0);opacity:1}}.back-to-top-inner{max-width:630px}.back-to-top-outer{position:fixed;bottom:100px;left:0;width:100%}@media screen and (min-width:768px){.back-to-top-inner{max-width:1920px}.back-to-top-outer{bottom:0}}