.icono{
  color: #fff;
  
  display: flex;
  justify-content: center;
  align-items: center;
  text-decoration: none;
  width: 45px;
   height: 45px;
  border: 5px solid #fff;
  border-radius: 50%;
  transition: all 0.3s;
  position: relative;
  top: 10%;
  margin:4px;
}

.icono::before{
  position: absolute;
  content:"";
  border-radius: 50%;
  background-color: #fff;
  top: 0;left: 0;
  width: 100%;height: 100%;
  transform: scale(0);
  transition: all 0.3s;
  z-index: -1;
}

.icono:hover{
  color: #b22023;
}

.icono:hover::before{
  transform: scale(1);
}