.site-back-top {
    position: fixed; right: max(24px, env(safe-area-inset-right)); bottom: calc(24px + env(safe-area-inset-bottom));
    z-index: 1000; display: grid; place-items: center; width: 50px; height: 50px; padding: 0;
    border: 1px solid #ffffffd9; border-radius: 50%; background: #fff8e9ed; color: #542744;
    box-shadow: inset 0 1px 1px #fff, 0 5px 18px #39273330; backdrop-filter: blur(12px);
    cursor: pointer; opacity: 0; visibility: hidden; pointer-events: none; transform: translateY(22px);
    transition: opacity 240ms ease, transform 280ms ease, visibility 280ms;
}
.site-back-top.is-visible { opacity: 1; visibility: visible; pointer-events: auto; transform: translateY(0); }
.site-back-top:hover { background: #fff1be; color: #542744; }
.site-back-top:focus-visible { outline: 3px solid #542744; outline-offset: 4px; }
.site-back-top::before, .site-back-top::after { content: none; }
.site-back-top svg { display: block; width: 22px; height: 22px; }
@media(max-width:767px) { .site-back-top { right: max(16px, env(safe-area-inset-right)); bottom: calc(16px + env(safe-area-inset-bottom)); width: 46px; height: 46px; } }
@media(prefers-reduced-motion:reduce) { .site-back-top { transition: none; transform: none; } }