*{margin:0;padding:0}
.scroll-to-top-btn{-webkit-backdrop-filter:blur(16px)saturate(180%);cursor:pointer;z-index:999;opacity:0;visibility:hidden;mix-blend-mode:difference;background:#ffffff14;border:1px solid #ffffff40;border-radius:50%;outline:none;justify-content:center;align-items:center;width:50px;height:50px;padding:0;transition:opacity .4s cubic-bezier(.16,1,.3,1),visibility .4s cubic-bezier(.16,1,.3,1),transform .4s cubic-bezier(.16,1,.3,1),background .3s,border-color .3s,box-shadow .3s;display:flex;position:fixed;bottom:25px;right:25px;transform:translateY(16px)scale(.85);box-shadow:0 8px 32px #00000026}.scroll-to-top-btn.is-visible{opacity:1;visibility:visible;transform:translateY(0)scale(1)}.scroll-to-top-btn:hover{background:#ffffff38;border-color:#ffffff80;transform:translateY(-4px)scale(1.08);box-shadow:0 12px 36px #00000040}.scroll-to-top-btn:active{transform:translateY(0)scale(.96)}.scroll-progress-ring{pointer-events:none;width:100%;height:100%;position:absolute;top:0;left:0;transform:rotate(-90deg)}.scroll-progress-bg{fill:none;stroke:#ffffff40;stroke-width:3.5px}.scroll-progress-indicator{fill:none;stroke:#fff;stroke-width:3.5px;stroke-linecap:round;transition:stroke-dashoffset .12s linear}.scroll-to-top-icon{color:#fff;z-index:2;font-size:1.15rem;transition:transform .3s cubic-bezier(.16,1,.3,1)}.scroll-to-top-btn:hover .scroll-to-top-icon{transform:translateY(-3px)}@media (max-width:768px){.scroll-to-top-btn{width:44px;height:44px;bottom:20px;right:20px}}