#luoghi_sub_container {
   position: relative;
}

.dot {
   position: absolute;
   width: 20px;
   height: 20px;
   margin-top:-10px;
   margin-left: -10px;
   background-color: red;
   border-radius: 50%;
}

@media (max-width: 768px) {
   .dot {
      width: 16px;
      height: 16px;
      margin-top:-8px;
      margin-left: -8px;
   }
}