@charset "utf-8";
    .btn-danger{
      margin: 0 auto;
    float: left;}
    
    .fa-angle-double-up {
      width: 30px;
  /*height: 100px;*/
  border: 2px solid;
  animation: blink-border-opacity-animation 1s infinite;
} 
    
    @keyframes blink-border-opacity {
  0% { border-color: transparent; }
  100% { border-color: white; }
}

@keyframes blink-border-opacity-animation {
  0% { border-style: solid; border-color: transparent; }
  50% { border-style: solid; border-color: white; }
  100% { border-style: solid; border-color: transparent; }
}