CSS Social Ribbon

DEMO

HTML

<div class="container">
  <button class="ribbon facebook">
    <span class="entypo-facebook"></span>
  </button>
  <button class="ribbon googleplus">
    <span class="entypo-gplus"></span>
  </button>
  <button class="ribbon twitter">
    <span class="entypo-twitter"></span>
  </button>
</div>
<div id="author">by: Skyler Knight</div>

CSS

@import url(http://fonts.googleapis.com/css?family=Allura);
@import url(http://weloveiconfonts.com/api/?family=entypo);

/* entypo */
[class*="entypo-"]:before {
  font-family: 'entypo', sans-serif;
}

.container{
  padding:0;
  margin: 0 auto;
  width: 410px;
 }
.ribbon{
  float: left;
  @include appearance(none);
  @include border-radius(5px 5px 0px 0px);
  @include transition(all 0.2s ease);
  cursor: pointer;
  border: none;
  background: blue;
  width: 150px;
  height: 250px;
  position: relative;
  color: white;
  padding: 5px;
  margin-right: -20px;
  -webkit-filter: drop-shadow(0 1px 10px rgba(0,0,0,.5));
        -moz-filter: drop-shadow(0 1px 10px rgba(0,0,0,.5));
        -ms-filter: drop-shadow(0 1px 10px rgba(0,0,0,.5));
        -o-filter: drop-shadow(0 1px 10px rgba(0,0,0,.5));
        filter: drop-shadow(0 1px 10px rgba(0,0,0,.5));
&:hover{
  margin-top: 20px;
  color:white;
}
span{
line-height: 20px;
font-size: 5em;
  }
&::before{
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    width: 0;
      height: 0;
      border-top: 50px solid blue;
      border-right: 100px solid transparent;
 }
&::after{
    content: '';
    position: absolute;
    top: 100%;
    right: 0;
    width: 0;
      height: 0;
      border-top: 50px solid blue;
      border-left: 100px solid transparent;
 }
}
.facebook{
  margin-top: 10px;
  background: #3b5998;
  color: darken(#3b5998, 20%);
  &::after{border-top-color: #3b5998}
  &::before{border-top-color: #3b5998}
  }
.googleplus{
  z-index: 999;
  background:#c4302b;
  color: darken(#c4302b, 20%);
  &::after{border-top-color: #c4302b}
  &::before{border-top-color: #c4302b}
  }
.twitter{
  margin-top: 10px;
  background: #00a0d1;
  color: darken(#00a0d1, 20%);
  &::after{border-top-color: #00a0d1}
  &::before{border-top-color: #00a0d1}
  }
#author{
  font-family: 'Allura', cursive;
  position: absolute;
  bottom: 25px;
  right: 40px;
  color: #999;
  font-size: 2em;
 
  }