After purge, all the hover styles are removed.

[metalbrick]

.toppest-right .iconfont {
  font-size: 1.4rem;
}
.toppest-right a:hover {
  text-decoration: none;
  color: #23a4db;
}
#topHeader {
  background: #08a1e5 url("../img/top-header.jpg") top no-repeat;
}

After css-purge

.toppest-right .iconfont {
  font-size: 1.4rem;
}
#topHeader {
  background: #08a1e5 url("../img/top-header.jpg") top no-repeat;
}