html{scroll-behavior:smooth}.back-to-top{position:fixed;z-index:40;right:clamp(18px,3vw,44px);bottom:clamp(18px,3vw,38px);width:48px;height:48px;border-radius:15px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1px;color:#fff;text-decoration:none;background:linear-gradient(145deg,#a74cff,#6d21d3);border:1px solid rgba(255,255,255,.28);box-shadow:0 14px 35px rgba(91,27,181,.42),inset 0 1px 0 rgba(255,255,255,.22);opacity:0;transform:translateY(18px) scale(.88);pointer-events:none;animation:show-backtop linear both;animation-timeline:scroll(root);animation-range:180px 340px;transition:filter .2s,box-shadow .2s}.back-to-top:before{content:"";position:absolute;inset:3px;border:1px solid rgba(255,255,255,.1);border-radius:11px}.back-to-top svg{width:18px;height:18px;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}.back-to-top span{font-size:5px;font-weight:900;letter-spacing:1.2px;margin-left:1px}.back-to-top:hover{filter:brightness(1.14);box-shadow:0 16px 40px rgba(128,48,225,.55),inset 0 1px 0 rgba(255,255,255,.3)}@keyframes show-backtop{to{opacity:1;transform:translateY(0) scale(1);pointer-events:auto}}@supports not (animation-timeline:scroll()){.back-to-top{opacity:1;transform:none;pointer-events:auto}}@media(max-width:600px){.back-to-top{width:44px;height:44px;border-radius:14px;right:16px;bottom:16px}}