Pulsing CSS Button

Adding some pulse to the button

HTML

<a class="large green button">Look at me!</a>

CSS

html {
 margin: 20px;
 font-family: arial;
}

@-webkit-keyframes greenPulse {
from { background-color: #b30b0b;}
50% { background-color: #b3360b; }
to { background-color: #b30b0b; }
}

a.green.button {
     margin: 0 auto;
-webkit-animation-name: greenPulse;
-webkit-animation-duration: 2s;
-webkit-animation-iteration-count: infinite;
    border-radius: 10px;
    padding: 4px 10px;
    box-shadow:
        0 1px 0 lightGrey inset;
    
   font-size:16px;
   color: #ffffff;
}