.back-to-top-button{left:50%;bottom:calc(14px + env(safe-area-inset-bottom,0px));color:#334155;-webkit-backdrop-filter:blur(8px);opacity:0;visibility:hidden;pointer-events:none;z-index:1200;background:#ffffffe6;border:1px solid #94a3b86b;border-radius:999px;justify-content:center;align-items:center;width:40px;height:40px;padding:0;line-height:0;transition:opacity .18s,transform .18s,visibility .18s,border-color .18s;display:inline-flex;position:fixed;transform:translate(-50%,14px);box-shadow:0 10px 22px #0f172a24}.back-to-top-button.visible{opacity:1;visibility:visible;pointer-events:auto;transform:translate(-50%)}.back-to-top-button:hover{border-color:#2563eb5c}.back-to-top-button:focus-visible{outline-offset:2px;outline:2px solid #2563eb}.back-to-top-button svg{flex:none;width:18px;height:18px;display:block;transform:translate(.5px)}[data-theme=dark] .back-to-top-button{color:#e2e8f0;background:#0f172ad6;border-color:#475569b8;box-shadow:0 12px 24px #00000057}[data-theme=dark] .back-to-top-button:hover{border-color:#818cf880}@media (width<=760px){.back-to-top-button{width:40px;height:40px}.back-to-top-button svg{transform:none}}