.back-to-top { position: fixed; right: 22px; bottom: 88px; z-index: 59; width: 48px; height: 48px; display: grid; place-items: center; border: 1px solid #dbeafe; border-radius: 50%; padding: 0; color: #096dd9; background: rgba(255, 255, 255, .96); box-shadow: 0 10px 26px rgba(15, 52, 96, .16); opacity: 0; visibility: hidden; transform: translateY(12px); pointer-events: none; cursor: pointer; transition: opacity .22s, visibility .22s, transform .22s, color .2s, background .2s; }
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); pointer-events: auto; }
.back-to-top:hover { color: #fff; background: #1890ff; }
.back-to-top:focus-visible { outline: 3px solid rgba(24, 144, 255, .28); outline-offset: 3px; }
.back-to-top svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }
@media (max-width: 640px) { .back-to-top { right: 14px; bottom: 82px; width: 46px; height: 46px; } }
@media (prefers-reduced-motion: reduce) { .back-to-top { transition: none; } }