<div class="container">
  
  <div class="envelope">
    <div class="paper">
      <ul>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
      </ul>
      <div class="noti">1</div>
    </div>
  </div>
  
  <div class="open"></div>
  
  <a href="javascript:">Open</a>
  
</div>

* {
  box-sizing: border-box;
}

html {
  background: #444444; 
}

.container {
  width: 130px;
  margin: 20px auto;
  text-align: center;
  position: relative;
}

.envelope {
  background: #ca336d;
  width: 100%;
  height: 80px;
  position: relative;
  box-shadow: 0 5px 0 #3a3d3c;
  margin: 85px 0 30px 0;
  z-index: 1;
}

.envelope:before,
.envelope:after {
  content: "";
  position: absolute;
  bottom: 0;  
}

.envelope:before {
  right: 0;
  border-bottom: 0px solid transparent;
  border-top: 80px solid transparent;
  border-right: 130px solid #dc447f;
  z-index: 1;
}

.envelope:after {
  left: 0;
  border-bottom: 0px solid transparent;
  border-top: 80px solid transparent;
  border-left: 130px solid #ea4c89;  
  z-index: 1;
}

.open {
  border-right: 65px solid transparent;
  border-top: 40px solid #c8336c;
  border-left: 65px solid transparent;  
  position: absolute;
  z-index: 9999;
  left: 0;
  top: 0;
  transform-origin: 0% 0%;
}

.paper {
  width: 110px;
  height: 75px;
  position: absolute;
  bottom: 0;
  left: 50%;
  margin-left: -55px;
  background: #f2f2f2;
  z-index: 0;
}

.paper:before {
  content: "";
  position: absolute;
}  

.paper:before {
  width: 110px;
  height: 75px;
  background: rgba(177,177,177,0.1);
  bottom: 0;
  left: 0;
}

.noti {
  position: absolute;
  top: -15px;
  right: -15px;
  width: 35px;
  height: 35px;
  border-radius: 35px;
  color: #fff;
  font: bold 20px/36px "Helvetica";
  text-align: center;
  background: #2ecc71;
  box-shadow: 0 4px 0 rgba(216,217,216, 0.7);
  opacity: 0;  
}

ul {
  margin: 25px auto 0 auto;
  padding: 0;
  display: block;
  width: 80%;
}

li {
  list-style: none;
  background: #d3d3d3;
  width: 100%;
  height: 5px;
  margin-bottom: 5px;
}

li:nth-child(1) {
  width: 50%;  
}

li:nth-child(2) {
  margin-bottom: 20px;  
  width: 20%;
}

a {
  background: #878387;
  text-decoration: none;
  text-transform: uppercase;
  color: #fff;
  letter-spacing: 1px;
  font: bold 13px "helvetica"; 
  padding: 8px 15px;
  box-shadow: 0 3px 0 #2a2c2b;
}

a:active,
a:hover {
   box-shadow: 0 1px 0 #2a2c2b;
}

/* TRIGGER ANIMATIONS */
.is-active .open {
  animation: foldUp 1s ease-in-out; 
  animation-fill-mode: forwards;
}
  
.is-active .paper {
  animation: paperUp 1.5s ease-in-out; 
  animation-fill-mode: forwards;
  animation-delay: 1s; /* W3C and Opera */ 
}

.is-active .noti {
  animation: noti 0.5s ease-in-out; 
  animation-fill-mode: forwards;
  animation-delay: 2s; /* W3C and Opera */ 
}

/* ANIMATIONS */
@keyframes foldUp {  
from {  
    transform: rotateX(0deg);
}  
to {  
    transform:rotateX(180deg);
    z-index: 0;
   }  
}

@keyframes noti {  
  from {  
    opacity: 0;
  } to {  
    opacity: 1;
   }  
}


@keyframes paperUp {  
  from {  
      height: 75px;
  } 60% {
      height: 130px;
  } 70% {
      height: 110px;
  } 80% {
      height: 130px;
  } 90% {
      height: 120px;
  } 100% {
      height: 130px;
  }  
}

/* IDEA FOR ICON FROM HERE -> http://dribbble.com/shots/1003867-Dribbble-Invitation?list=popular&offset=2 */

/* Trigger Animation */
$('a').on('click', function() {
    $('.container').addClass('is-active');
    $(this).remove();
});