Edit in JSFiddle

<ul class="social-networks square spin-icon">
  <li><a href="https://www.linkedin.com/" class="icon-linkedin">LinkedIn</a></li>
  <li><a href="https://twitter.com/" class="icon-twitter">Twitter</a></li>
  <li><a href="https://www.facebook.com/" class="icon-facebook">Facebook</a></li>
  <li><a href="https://twitch.tv" class="icon-twitch">Twitch</a></li>
  <li><a href="https://github.com" class="icon-github">GitHub</a></li>
  <li><a href="https://pinterest.com" class="icon-pinterest">Pinterest</a></li>
  <li><a href="https://instagram.com" class="icon-instagram">Instagram</a></li>
  <li><a href="https://vimeo.com" class="icon-vimeo">Vimeo</a></li>
</ul>

<ul class="social-networks spin-icon">
  <li><a href="https://www.linkedin.com/" class="icon-linkedin">LinkedIn</a></li>
  <li><a href="https://twitter.com/" class="icon-twitter">Twitter</a></li>
  <li><a href="https://www.facebook.com/" class="icon-facebook">Facebook</a></li>
  <li><a href="https://twitch.tv" class="icon-twitch">Twitch</a></li>
  <li><a href="https://github.com" class="icon-github">GitHub</a></li>
  <li><a href="https://pinterest.com" class="icon-pinterest">Pinterest</a></li>
  <li><a href="https://instagram.com" class="icon-instagram">Instagram</a></li>
  <li><a href="https://vimeo.com" class="icon-vimeo">Vimeo</a></li>
</ul>

<ul class="social-networks bounce">
  <li><a href="https://www.linkedin.com/" class="icon-linkedin">LinkedIn</a></li>
  <li><a href="https://twitter.com/" class="icon-twitter">Twitter</a></li>
  <li><a href="https://www.facebook.com/" class="icon-facebook">Facebook</a></li>
  <li><a href="https://twitch.tv" class="icon-twitch">Twitch</a></li>
  <li><a href="https://github.com" class="icon-github">GitHub</a></li>
  <li><a href="https://pinterest.com" class="icon-pinterest">Pinterest</a></li>
  <li><a href="https://instagram.com" class="icon-instagram">Instagram</a></li>
  <li><a href="https://vimeo.com" class="icon-vimeo">Vimeo</a></li>
</ul>
@font-face {
	font-family: 'icomoon';
	src:url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/93/icomoon.eot?3qkin2');
	src:url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/93/icomoon.eot?#iefix3qkin2') format('embedded-opentype'),
		url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/93/icomoon.woff?3qkin2') format('woff'),
		url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/93/icomoon.ttf?3qkin2') format('truetype'),
		url('fhttps://s3-us-west-2.amazonaws.com/s.cdpn.io/93/icomoon.svg?3qkin2#icomoon') format('svg');
	font-weight: normal;
	font-style: normal;
}

.social-networks {
  margin: 0 0 35px;
  padding: 0;
  font-size: 0;
  text-align: center;

  li {
    display: inline-block;
  }

  a {
    display: block;
    position: relative;
    margin: 0 7px;
    width: 68px;
    height: 68px;
    font-size: 0;
    line-height: 0;
    text-align: center;
    text-decoration: none;

    &:before {
      content: "";
      position: absolute;
      top: 50%;
      left: 50%;
      width: 100%;
      height: 100%;
      margin-top: -50%;
      margin-left: -50%;
      border-radius: 100px;
      background-color: #1f2027;
      transition: all 400ms;
    }

    &:after {
      position: relative;
      display: block;
      font-family: 'icomoon';
      speak: none;
      font-style: normal;
      font-weight: normal;
      font-variant: normal;
      text-transform: none;
      line-height: 1;
      color: #fff;
      font-size: 26px;
      line-height: 66px;
    }

    &:hover, &:focus {
      text-decoration: none;
    }
  }
  
  &.spin-icon a:hover:after, &.spin-icon a:focus:after {
    transition: transform 0.4s ease-out;
    transform: rotateZ(360deg);
  }
  
  &.square a:hover:before, &.square a:focus:before {
    border-radius: 0;
  }
  
  &.bounce a:hover, &.bounce a:focus {
    animation: bounce 1s;
  }
  
  $networks: linkedin '\eac9' #0077b5, facebook '\e603' #3b5998, twitter '\e618' #00b0ed, github '\eab1' #4183c4, instagram '\e604' #3f729b, vimeo '\ea9c' #1ab7ea, twitch '\ea9b' #6441a5, pinterest '\e605' #cc2127;
  
  @each $network in $networks {
     .icon-#{nth($network, 1)} {
       &:after {
         content: '#{nth($network, 2)}';
      }

      &:hover:before, &:focus:before {
        background: nth($network, 3);
      }
    }
  }
}

@keyframes bounce {
  0%, 20%, 53%, 80%, 100% {
    transition-timing-function: cubic-bezier(0.215, 0.610, 0.355, 1.000);
    transform: translate3d(0,0,0);
  }

  40% {
    transition-timing-function: cubic-bezier(0.755, 0.050, 0.855, 0.060);
    transform: translate3d(0, -6px, 0);
  }

  70% {
    transition-timing-function: cubic-bezier(0.755, 0.050, 0.855, 0.060);
    transform: translate3d(0, -4px, 0);
  }

  90% {
    transform: translate3d(0,-2px,0);
  }
}

/* Extra stuff just to make the demo pretty. */
body {
  padding: 35px 0;
  color: #fff;
  font-family: 'Lora', serif;
  font-size: 14px;
  text-align: center;
  line-height: 24px;
  background: #262730 url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/93/noise-bg.png) repeat 0 0;
}

h1 {
  margin-bottom: 0px;
  font-size: 55px;
  line-height: 1.0;
}

h2 {
  font-family: 'Montserrat', sans-serif;
  margin-bottom: 45px;
  font-size: 12px;
  text-transform: uppercase;
}

footer {
  margin: 75px 0 35px;
}

a {
  color: #4183c4;
  text-decoration: none;
  
  &:hover {
    color: lighten(#4183c4, 15%);
  }
}