.btn-facebook-alt i {
  color: #23386a;
}
.btn-twitter-alt i {
  color: #0098d0;
}
.btn-google-alt i {
  color: #b6362d;
}
.btn-linkedin-alt i {
  color: #0073b2;
}
.btn-pinterest-alt i {
  color: #ab171e;
}
.btn-github-alt i {
  color: #333;
}

.icon-twitter {
  background-image: url(twitter_32.png);
  @include icon-generic;
}

.icon-github {
  background-image: url(github_32.png);
  @include icon-generic;
}

.btn-facebook-alt i {
  color: #23386a;
}
.btn-twitter-alt i {
  color: #0098d0;
}
.btn-google-alt i {
  color: #b6362d;
}
.btn-linkedin-alt i {
  color: #0073b2;
}
.btn-pinterest-alt i {
  color: #ab171e;
}
.btn-github-alt i {
  color: #333;
}

.icon-twitter {
  background-image: asset-url("twitter_32.png");
  @include icon-generic;
}

.icon-github {
  background-image: asset-url("github_32.png");
  @include icon-generic;
}

Use asset-url for login icons
Use asset-url for login icons
