<div class='container'>
  <span class='pulse-button'>pulse</span>
</div>

@import "compass/css3";

body, html {
  height: 100%;
  background: #fff;
}

.container {
  width: 200px;
  height: 100%;
  margin: 0 auto 0;
  -webkit-perspective: 1000;
  -webkit-backface-visibility: hidden;
  background: #fff;
}

.pulse-button {
  position: relative;
  top: 50%;
  left: 50%;
  margin-left: -50px;
  margin-top: -50px;
  display: block;
  width: 100px;
  height: 100px;
  font-size: 1.3em;
  font-weight: light;
  font-family: 'Trebuchet MS', sans-serif;
  text-transform: uppercase;
  text-align: center;
  line-height: 100px;
  letter-spacing: -1px;
  color: white;
  border: none;
  border-radius: 50%;
  background: #5a99d4;
  cursor: pointer;
  box-shadow: 0 0 0 0 rgba(#5a99d4, .5);
  -webkit-animation: pulse 1.5s infinite;
}
.pulse-button:hover {
  -webkit-animation: none;
}

@-webkit-keyframes pulse {
  0% {
    @include transform(scale(.9));
  }
  70% {
    @include transform(scale(1));
    box-shadow: 0 0 0 50px rgba(#5a99d4, 0);
  }
    100% {
    @include transform(scale(.9));
    box-shadow: 0 0 0 0 rgba(#5a99d4, 0);
  }
}