.scroll-top-btn{position:fixed;bottom:32px;right:32px;z-index:9999;width:48px;height:48px;border:none;border-radius:50%;background:#ba1d41;color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 16px rgba(186,29,65,.35);opacity:0;visibility:hidden;transform:translateY(20px);transition:opacity .3s ease,visibility .3s ease,transform .3s ease,background .2s ease}.scroll-top-btn.is-visible{opacity:1;visibility:visible;transform:translateY(0)}.scroll-top-btn:hover{background:#a0182f;box-shadow:0 6px 24px rgba(186,29,65,.5);transform:translateY(-2px)}.scroll-top-btn:active{transform:translateY(0)}.scroll-top-btn__progress{position:absolute;inset:0;border-radius:50%;border:2.5px solid transparent;border-top-color:rgba(255,255,255,.6);pointer-events:none;transition:transform .1s linear;transform:rotate(0deg)}@media (max-width:600px){.scroll-top-btn{bottom:20px;right:20px;width:42px;height:42px}}