div.a {
width: 170px;
height:100px;
 background-color:red;
position:fixed;
    
}

.center {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 30%;
}

 /* Style all font awesome icons */
.fa {
  padding: 20px;
  font-size: 30px;
  width: 20px;
  text-align: center;
  text-decoration: none;
  border-radius: 50%;

}

/* Add a hover effect if you want */
.fa:hover {
  opacity: 0.7;
}

/* Set a specific color for each brand */

/* Facebook */
.fa-facebook {
  background: #3B5998;
  color: white;
}

/* Twitter */
.fa-youtube {
  background: #FF0000;;
  color: white;
}