.back-to-top{position:fixed;right:1.2rem;bottom:5rem;z-index:25;width:2.7rem;height:2.7rem;border-radius:50%;border:1px solid var(--line);background:var(--card-grad),var(--panel-soft);color:var(--text);display:flex;align-items:center;justify-content:center;cursor:pointer;box-shadow:var(--shadow-sm);opacity:0;visibility:hidden;transform:translateY(8px);transition:opacity .25s ease,transform .25s ease,visibility .25s ease,border-color .2s ease}@media(max-width:420px){.back-to-top{right:.8rem;bottom:4.6rem}}.back-to-top.is-visible{opacity:1;visibility:visible;transform:translateY(0)}.back-to-top:hover{border-color:var(--line-strong);transform:translateY(-2px)}