button.scroll-to-top{position:fixed;right:24px;bottom:24px;z-index:9999;display:grid;width:52px;height:52px;place-items:center;border:1px solid #000;border-radius:50%;background:#000;color:#fff;cursor:pointer;font-size:28px;line-height:1;opacity:0;pointer-events:none;transform:translateY(12px);transition:opacity .2s ease,transform .2s ease,background .18s ease}button.scroll-to-top.is-visible{opacity:1;pointer-events:auto;transform:translateY(0)}