.fab{position:fixed; right:18px; bottom:18px; z-index:999}
.fab__btn{
  width:56px;height:56px;border-radius:50%;
  border:1px solid #1f2937;background:#0b1220;color:#fff;
  box-shadow:0 8px 24px rgba(0,0,0,.2); cursor:pointer; font-size:20px
}
.fab__btn:hover{filter:brightness(1.1)}
.fab__list{
  list-style:none;margin:10px 0 0;padding:8px;
  background:#0b1220;border:1px solid #1f2937;border-radius:14px;
  box-shadow:0 12px 28px rgba(0,0,0,.25)
}
.fab__item{
  display:block;padding:8px 12px;color:#fff;text-decoration:none;border-radius:8px
}
.fab__item:hover{background:rgba(255,255,255,.08)}
/* Acessibilidade – texto só para leitores de tela */
.sr-only{position:absolute;left:-9999px;top:auto;width:1px;height:1px;overflow:hidden}
@media (prefers-reduced-motion:no-preference){
  .fab__list{transition:transform .2s ease, opacity .2s ease}
}
.fab__item.is-active { 
  background: rgba(255,255,255,.12); 
  font-weight: 600; 
}