.icon-facebook-white { background-image: url('png/facebook-white.png'); background-repeat: no-repeat; }

.icon-facebook { background-image: url('png/facebook.png'); background-repeat: no-repeat; }

.icon-twitter-white { background-image: url('png/twitter-white.png'); background-repeat: no-repeat; }

.icon-twitter { background-image: url('png/twitter.png'); background-repeat: no-repeat; }