.button {
    display: inline-block;
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    cursor: pointer;
    -webkit-transition: all 0.2s ease;
    transition: all 0.2s ease;
}
.button-flash {
    -webkit-animation: glowing 1500ms infinite;
    -moz-animation: glowing 1500ms infinite;
    -o-animation: glowing 1500ms infinite;
    animation: glowing 1500ms infinite;
    opacity: 1;
}
@-webkit-keyframes glowing {
  0% { background-color: #B20000; -webkit-box-shadow: 0 0 3px #B20000; }
  50% { background-color: #FF0000; -webkit-box-shadow: 0 0 40px #FF0000; }
  100% { background-color: #B20000; -webkit-box-shadow: 0 0 3px #B20000; }
}