.sfe-top{position:fixed;right:16px;bottom:16px;z-index:99998;width:44px;height:44px;border-radius:999px;display:flex;align-items:center;justify-content:center;background:#222;color:#fff;font-size:18px;text-decoration:none;opacity:.85;transition:opacity .2s,transform .15s;box-shadow:0 8px 30px rgba(0,0,0,.25)}
.sfe-top:hover{opacity:1;transform:translateY(-2px)}
.sfe-top--hide{display:none}