.scroll-to-top-button{position:fixed;right:16px;bottom:40px;color:white;padding:12px;border-radius:50%;box-shadow:0 4px 6px rgba(0,0,0,.1);transition:opacity .3s ease-in-out;border:none;cursor:pointer}.scroll-to-top-button,.scroll-to-top-button:hover{background-color:var(--color2)}.visible{opacity:1}.hidden{opacity:0;pointer-events:none}