.back-to-top{position:fixed;right:24px;bottom:calc(24px + var(--footer-clearance,0px) + env(safe-area-inset-bottom,0px));z-index:50;display:flex;align-items:center;justify-content:center;width:48px;height:48px;padding:0;border:0;border-radius:50%;background:#222;color:#fff;box-shadow:0 4px 14px #0003;cursor:pointer;transition:background .18s,transform .18s}
.back-to-top[hidden]{display:none}
.back-to-top svg{width:24px;height:24px}
.back-to-top:hover{background:#e60012;transform:translateY(-2px)}
.back-to-top:focus-visible{outline:2px solid #e60012;outline-offset:4px}
@media(max-width:640px){.back-to-top{right:16px;bottom:calc(16px + var(--footer-clearance,0px) + env(safe-area-inset-bottom,0px))}}
@media(prefers-reduced-motion:reduce){.back-to-top{transition:none}}