back-to-top{position:fixed;bottom:2rem;right:2rem;z-index:100;opacity:0;visibility:hidden;transition:opacity var(--duration-default) ease,visibility var(--duration-default) ease}back-to-top.is-visible{opacity:1;visibility:visible}back-to-top button{width:48px;height:48px;background:rgba(var(--color-background),1);color:rgba(var(--color-foreground),1);display:flex;align-items:center;justify-content:center;transition:opacity var(--duration-default) ease}back-to-top button:hover{opacity:.75}back-to-top button svg{width:16px;height:16px;fill:currentColor}