blockquote .wpkmkz-tweetblock-btn {
  margin: 20px;
  background: #00acee url(../img/twitter.png) left center no-repeat;
  color: #fff;
  font-size: 13px;
  text-decoration: none;
  padding: 5px 12px;
  padding-left: 26px;
  border-radius: 4px;
}

blockquote .wpkmkz-tweetblock-btn:hover {
  color: #eee;
}