.back-to-top{position:fixed;right:20px;bottom:calc(24px + env(safe-area-inset-bottom,0px));z-index:1000;width:48px;height:48px;padding:0;display:flex;align-items:center;justify-content:center;border:1px solid #7ad5ff;border-radius:50%;background:#34b8ff;color:#071423;box-shadow:0 4px 18px rgba(0,0,0,.3);cursor:pointer;touch-action:manipulation}
.back-to-top[hidden]{display:none!important}
.back-to-top:hover{background:#7ad5ff}
.back-to-top:focus-visible{outline:3px solid #fff;outline-offset:4px}
@media(max-width:580px){.back-to-top{right:14px;bottom:calc(20px + env(safe-area-inset-bottom,0px))}}