developer.css

* {
  box-sizing: border-box;
}

.column {
  float: left;
  width: 33.33%;
  padding: 70px;
  height: 70px;
}

/* Clearfix (clear floats) */
.row::after {
  content: "";
  clear: both;
  display: table;
}

/* Responsive layout - makes the three columns stack on top of each other instead of next to each other */
@media screen and (max-width: 500px) {
  .column {
    width: 100%;
    height:100% ;
  }
}

.fa {
  padding: 20px;
  font-size: 30px;
  width: 60px;
  text-align: center;
  text-decoration: none;
  margin: 5px 2px;
  border-radius: 50%;

}

.fa-linkedin {
  background: #007bb5;
  color: white;
}

.fa-twitter {
  background: #55ACEE;
  color: white;
}

.fa:hover {
    opacity: 0.7;
}